Field Efficacy Evaluation of Commonly Used Anthelmintics Against Gastrointestinal Nematodes on Naturally Infected Horses in and around Tulu Awuliya Town, North East Ethiopia

Field Efficacy Evaluation of Commonly Used Anthelmintics Against Gastrointestinal Nematodes on Naturally Infected Horses in and around Tulu Awuliya Town, North East Ethiopia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Field Efficacy Evaluation of Commonly Used Anthelmintics Against Gastrointestinal Nematodes on Naturally Infected Horses in and around Tulu Awuliya Town, North East Ethiopia Seid Kassaw, Alula Alemayehu Assen, Ahmed Yasine This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8864548/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Gastrointestinal nematode (GIN) infections are major constraints to horse productivity, with effective control relying largely on routine use of anthelmintic drugs. However, the emergence of anthelmintic resistance threatens the long term sustainability of this strategy. Therefore, a field-based experiment was conducted from November 2020 to May 2021 in and around Tullu-Awliya town of South Wollo Zone to evaluate the efficacy of commonly used anthelmintics against GINs in naturally infected horses and to assess the control practices of horse owners. Fecal samples from 520 randomly selected horses were examined using flotation and modified McMaster techniques. Horses with fecal egg counts (EPG ≥ 150) were assigned into six groups of ten, representing cart and pack horses. Four groups received either Ivermectin or Fenbendazole, while two served as untreated controls. Fecal samples collected on day 0 and day 14 were subjected to fecal egg count reduction tests (FECRT) to determine anthelmintic efficacy. Copro culture and modified Baermann techniques were used to identify L3 larvae associated with suspected resistance. Egg reappearance period (ERP) was also conducted to detect anthelmintic efficacy in packing horses. Additionally, a questionnaire survey involving 201 horse owners documented helminth control and anthelmintic use practices. The FECRT results showed mean fecal egg count reductions of 94.01% for Ivermectin and 99.6% for Fenbendazole, with significant differences between treated and control groups. Ivermectin exhibited suspected resistance, and Strongylus vulgaris, Strongylus equinus, and Cyathostomum spp. were identified post treatment of Ivermectin. Moreover, ERP results suggested no anthelmintic resistance in pack horses. The survey indicated that Ivermectin 62.3%, followed by Fenbendazole 31.8%, were the most widely used anthelmintics. These findings highlight the need for improved awareness of rational anthelmintic use and adoption of resistance‑management strategies, alongside further studies on factors contributing to reduced drug efficacy. Animal Science Anthelmintic resistance ERP FECRT Gastrointestinal nematodes Horses Tulu-Awlia Figures Figure 1 Figure 2 Figure 3 1. Introduction Gastrointestinal helminth infections remain one of the most significant constraints to profitable equine production worldwide, causing reduced performance, morbidity, and economic loss [ 1 ]. Equines are highly susceptible to a wide range of parasitic infections [ 2 ], and an apparently healthy horse may harbor hundreds of thousands of gastrointestinal helminths, including nematodes, cestodes, and trematodes [ 3 ]. Among these, gastrointestinal nematodes (GIN) such as Strongylidae, Spiruridae, Oxyuridae, Trichostrongylidae, Rhabditidae, and Ascaridae represent the most prevalent and economically important groups affecting horses [ 4 , 5 ]. In Ethiopia, several studies have reported a high burden of gastrointestinal nematodes in equines, with notable species including Strongyles (99.5%) and Parascaris equorum (53%) in Sululta and Gefersa by [ 6 ], Parascaris equorum (70.7%), Oxyuris equi (4.6%), and Dictyocaulus arnfieldi (22.6%) in Dessie and Kombolcha by [ 7 ], and Tridontophorus spp. (52.8%) in Dugda Bora by [ 8 ]. Additional reports from Dessie and Kombolcha indicated the presence of Strongyloides westeri (11%), while in Gonder town, cyathostomum spp. (99.5%) was detected, as documented by [ 9 ]. Together, these findings underscore the widespread distribution and high prevalence of diverse gastrointestinal nematodes in Ethiopian equine populations. The currently available tools for protecting equines from many gastrointestinal helminths depend mainly on using chemical treatments, namely anthelmintics, in many parts of the world. Chemical control through anthelmintics remains the primary strategy for managing equine helminths globally [ 10 ]. The widespread availability and routine use of broad‑spectrum anthelmintics such as benzimidazoles (e.g., Fenbendazole) and macrocyclic lactones (e.g., Ivermectin) have improved parasite control but also accelerated the emergence of anthelmintic resistance [ 11 , 12 ]. Resistance develops when a proportion of the parasite population survives treatment and passes heritable resistance traits to subsequent generations [ 13 , 14 ]. Risk factors include frequent and repeated treatments, incorrect dosing, exclusive reliance on chemical control, and lack of integrated parasite‑management practices [ 15 , 16 ]. Globally and in Ethiopia, the definition of resistance has been reported to be debated, as some consider it total anthelmintics' failure, while others define it as a decrease in efficacy, or perhaps when the maximum dose is no longer effective [ 17 ]. Standardized methods for detecting anthelmintic resistance include the Fecal Egg Count Reduction Test (FECRT), which evaluates the percentage reduction of fecal egg counts after treatment, and the Egg Reappearance Period (ERP), which measures how long after treatment parasite eggs reappear in feces, an important early indicator of developing resistance [ 18 ]. In Ethiopia, despite numerous studies documenting the prevalence of equine helminths [ 19 , 20 , 21 , 22 , and 23 ], research on anthelmintic efficacy and resistance in horses is extremely limited, with most investigations focusing on ruminants. The situation is further complicated by the widespread misuse, illegal trade, and irrational administration of anthelmintics due to the absence of stringent national policies [ 24 , 25 ]. Although gastrointestinal nematodes of horses are widely recognized in Ethiopia, no previous study has evaluated the field efficacy of commonly used anthelmintics (Fenbendazole and Ivermectin) against equine GIN in and around Tulu Awuliya town using both FECRT and ERP methods. In Tulu Awuliya town, Fenbendazole and Ivermectin are the most commonly used anthelmintics. However, horse owners frequently report reduced drug performance despite regular deworming practices. This suggests a possible decline in drug efficacy, yet no field‑based evaluation has been conducted in the area. Therefore, the present study was designed to evaluate the field efficacy of commonly used anthelmintics against gastrointestinal nematodes of naturally infected horses in and around Tulu Awuliya town and to assess the helminth‑control and anthelmintic‑use practices of horse owners in the study area. 2. MATERIALS AND METHODS 2.1. Study Area The study was conducted from November 2020 to May 2021 in Tullu Awuliya, located in South Wollo, Northeast Ethiopia, approximately 501 km from Addis Ababa (Fig. 1 ). The area lies at a latitude of 11°N and a longitude of 39°E, encompassing both highland and midland agro-ecological zones. Elevations range between 1,500 and 3,700 meters above sea level. According to the Legambo District Agricultural Extension Office (2019), the area experiences mean minimum and maximum temperatures of 16°C and 27°C, respectively, and an average annual rainfall of 933.9 mm. Agriculture in the district is predominantly cereal-based, with barley and wheat serving as major crops, and oxen and horses providing essential draught power for plowing. The main livestock species reared in the area include cattle, sheep, goats, horses, donkeys, mules, and poultry. Based on data from the Legambo Wereda Animal Resources Office (2020), the equine population comprises 26,639 donkeys, 10,584 horses, and 3,587 mules. 2.2. Study Animals The study animals were horses managed under extensive and semi-intensive production systems and owned by local farmers. During sampling, information on each horse, including age, sex, working type, management system, and body condition, was recorded. Age was determined using dentition and owners’ birth records following the method described by [ 26 ], Based on this, horses were categorized into three age groups: young ( 10 years). Body condition was categorized as poor, moderate, and good using visual appraisal and manual palpation of the spinous and transverse processes [27]. The study horses were all local breeds and were primarily used for human transportation and packing purposes. 2.3. Sample Size Determination The sample size for fecal egg count (FEC) was determined according to [ 28 ], considering the expected prevalence of 70.4% [ 7 ], with 5% desired absolute precision. Hence, the sample size was estimated by substituting into the formula $$\:\text{N}=\frac{1.96²Pexp(1-Pexp)}{d²}$$ Where, N= sample size, Pexp = expected prevalence, d2 = absolute precision Based on the formula, the total sample was 320, but the sample size was increased to 520 horses in order to increase the chance of having enough horses with high fecal egg count for the experimental study and to reduce sampling error and subsequently increase the accuracy. The sample size for the questionnaire survey was determined using the formula (n = 0.25/SE2) proposed by [ 29 ] at a standard error (SE) of 0.05 with a 95% confidence interval. Based on the formula, the total number of respondents was 100. However, the number of respondents was increased to 201 to get more accurate data from the owners. 2.4. Study Design and Sampling techniques A field experimental study was conducted to evaluate the efficacy of commonly used anthelmintics against gastrointestinal nematodes in horses in Tulu Awuliya town. A total of 520 horses were randomly selected using a lottery method for parasitological screening and fecal egg count (FEC) assessment. Each horse was identified using the owner’s name identification system. Fecal samples collected from all study horses were examined using simple flotation and the modified McMaster technique [ 30 , 31 ]. Of the 520 horses examined, 374 were found to be naturally infected with GIT nematodes. From these infected horses, 60 were selected for the field experimental trial based on the criteria recommended by the World Association for the Advancement of Veterinary Parasitology (WAAVP). Inclusion criteria required horses to have a medium body condition, be adults, be managed under extensive husbandry, and not be treated with any anthelmintic in the preceding three months. Additionally, only male cart horses used for transportation and non‑pregnant female pack horses used for packing were included. All selected horses were required to have an FEC ≥ 150 eggs per gram (EPG) [ 32 ]. The 60 horses were randomly allocated into six experimental groups (10 horses each): Ivermectin‑treated, Fenbendazole‑treated, and untreated control groups for both cart and pack horses. Horses were treated according to manufacturer‑recommended doses using Fenbendazole (2400 mg, Rangfebenda 20FB0404) or Ivermectin 1% (Ivertor 201001) in (Table 1 ). Table 1 Experimental layout Groups Treatment Description of drugs G 1 Cart horses Treated with Ivermectin Ivermectin 1%, 0.2 mg/kg Po, Ivertor Habei Chengshengtang Animal Pharmaceuticals Co., Ltd/China Batch No.201001 and Exp date, 10/2023 G 2 Cart horses Treated with Fenbendazole Fenbendazole 2400 mg, 7.5 mg /kg with grain Rangfebenda, Chenqdu Qiankun Veterinary Pharmaceuticals Co., Ltd./ China Batch No. 20FB0404 and exp. date, 10/2023 G 3 Cart horses - Un treated G 4 Pack horses Treated with Ivermectin Ivermectin 1%, 0.2 mg/kg Po, Ivertor Habei Chengshengtang Animal Pharmaceuticals Co., Ltd/China Batch No.201001 and Exp date, 10/2023 G 5 Pack horses Treated with Fenbendazole Fenbendazole 2400 mg, 7.5 mg /kg with grain Rangfebenda, Chenqdu Qiankun Veterinary Pharmaceuticals Co., Ltd./ China Batch No. 20FB0404 and exp. date, 10/2023 G 6 Pack horses - Un treated 2.5. Data Collection Methods 2.5.1. Questionnaire survey A structured questionnaire was prepared and translated into the local language of the respondents (Amharic) and pretested before the commencement of the study. A total of 201 horse owners were randomly selected and interviewed in order to collect information on the anthelmintic utilization and helminth control practices. The respondents were horse owners whose horses were included or selected for the preliminary screening test by fecal examination and FEC determination. The questionnaire focused mainly on information on the commonly used anthelmintics, the frequency of use, criteria for selection, and the main source of the anthelmintics, the management system, and observations on the responses after treatment (efficacy). 2.5.2. Faecal sample collection and examination Fecal samples were collected directly from the rectum using clean gloves for screening and fecal egg count (FEC) analysis. During sampling, sampling date, body condition, working type, age, sex, management system, and owner identity were recorded for each horse. For the experimental study, fecal samples were collected per rectum before treatment (day 0) and after treatment (day 14). Each sample was placed in a properly labeled container and transported in an ice box to the Parasitology Laboratory of Wollo University, Faculty of Veterinary Medicine, and the Akesta Animal Health Clinic Laboratory. Samples were stored at + 4°C when immediate processing was not possible, and all were processed within 48 hours. Parasitological examination involved both qualitative and quantitative techniques. Simple flotation was used to detect gastrointestinal nematode eggs, while the modified McMaster method was employed to determine FEC and assess infection intensity [ 33 ]. For flotation, 3 g of feces were mixed with 45 ml of saturated NaCl solution, strained, centrifuged, and topped with flotation fluid to create a reverse meniscus before placing a coverslip for microscopic examination. For the modified McMaster technique, 3 g of feces were mixed with 42 ml of saturated NaCl, strained, centrifuged, and the mixture was used to fill the McMaster counting chamber, after which eggs per gram of feces were counted [ 31 , 33 ]. Anthelmintic efficacy was evaluated using the fecal egg count reduction test (FECRT), following standard procedures described by [ 32 ]. 2.5.3. Faecal egg count reduction test (FECR) The fecal egg count reduction test was used for the evaluation of anthelmintic efficacy. The efficacy of the anthelmintics was tested according to the World Association for the Advancement of Veterinary Parasitology (WAAVP) recommendations for the detection of anthelmintic efficacy in horses by the percentage reduction of mean egg excretion on the 14th day post treatment [ 32 ]. The efficacy was calculated by comparing the arithmetic mean of egg counts 14 days post-treatment to those of day 0 using the formula. When the percentage reduction of EPG was equal to or more than 95%, and the lower 95% CI was equal to or more than 90%, the anthelmintic was considered effective. Resistance to an anthelmintic is considered to be present if the value of the FECR percentage is less than 95% and the lower confidence limit of the confidence interval is less than 90%. If only one of these criteria is met, anthelmintic resistance is suspected [ 32 , 34 , and 35 ]. 2.5.4. Larvascopy A modified Baermann technique was used to isolate the 3rd larvae stage of nematode parasites from fecal cultures. In the current study, fecal culture of eggs of third-stage larvae was undertaken along with the fecal egg counting to differentiate the genus or species of GIT nematodes before treatment on day 0 and after treatment on day 14 in each anthelmintic treatment and the control groups. Fecal samples containing nematode eggs from each group of horses were pooled, finely crushed using a mortar and pestle, and cultured in Petridish. A small amount of water was added to moisten the fecal sample, and incubated at 27 oC for 10 days and mixed periodically. Then, the larvae were recovered using a modified Baermann technique [ 36 ]. After collection of the larvae, a drop of the sample was mounted on a microscopic slide, killed with Lugol’s iodine, and identified at the genus/species level in each group based on morphological characteristics as described previously [ 37 , 38 ]. 2.5.5. Egg reappearance period (ERP) Egg reappearance period (ERP) is the amount of time it takes for parasite eggs to begin recurring in the feces following anthelmintic treatment [ 39 ]. The egg reappearance period was used for the detection of anthelmintic efficacy when initial efficacy was 100% (egg disappearance) [ 40 ]. It was described by using three important parameters: (1) the first time a positive fecal egg count was recorded as post treatment [ 41 ], (2) 10% of the Day 0 value [ 42 , 43 ]. These parameters were fulfilled, indicating shorter egg reappearance, which leads to a reduction in the efficacy of anthelmintics [ 44 ]. 2.6. Data Management and Analysis Data were collected and stored in Microsoft Excel, analyzed using SPSS V-20 statistical software [ 45 ]. The preliminary data of helminth infection and questionnaire data were analyzed using descriptive statistics to compute the frequency and percentages. A P < 0.05 was used to determine the level of significance. One-way ANOVA was used to compare the mean number of eggs per gram of each experimental group. The effectiveness of each anthelmintic was evaluated by computing the mean of fecal egg count reduction (FECRT) for each treatment group. 3. RESULTS 3.1. Questionnaire Survey on Horse Owners’ Helminth Control Practices and Anthelmintic Use A majority (62.7%) indicated that veterinary services were sufficient, and 70.1% reported using anthelmintics for their horses. Ivermectin was the most frequently used drug (63.2%), followed by Fenbendazole (31.8%), and while 5.0% used both, Fig. 2 A. The main reasons for drug preference were accessibility (56.7%), price (28.9%), and ease of use (14.4%), Fig. 2 B. Government veterinary clinics were the predominant drug source (65.1%), with private clinics (20.9%), open markets (8%), and illegal sellers (6%) also contributing. Most treatments were administered by government veterinarians (67.7%), though a smaller proportion relied on private veterinarians (10.3%). Body weight estimation before dosing was commonly done by eye (78.1%), while only 21.9% used prescription‑based estimation. Anthelmintics were mainly administered for general disease conditions (58.2%), abdominal problems (31.7%), and inappetence (9.9%). Regarding treatment frequency, 49.7% dewormed their horses every two months, 31.8% every six months, 10.5% annually, and 7.5% had never dewormed their horses in (Table 2 ). Table 2 Summary of horse owners’ helminth control practices and anthelmintic use in the study area S. No. Variables Response Frequency (%) 1. There are sufficient veterinary services Yes 126(62.7%) No 75(37.3%) 2 Use of anthelmintic to treat your horses Yes 141(70.1%) No 60(29.9%) 3 Most commonly used anthelmintic Ivermectin 127(63.2%) Fenbendazole 64(31.8%) Both 10(5.0%) 4 The reason behind preference of anthelmintic Accessibility 114(56,7%) Considerable price 58(28.9%) Comfortability to use 29(14.4%) 5 The common sources of anthelmintic Governmental clinic 131(65.1%) Private clinic 42(20.9%) Open market 16(8%) Illegal sellers 12(6%) 6 Who prescribing and administering anthelmintic By governmental veterinarian 136(67.7%) By Private veterinarian 49(10.3%) 7 How to estimate your horse body weight During administration By others person 4(2%) By eye estimation 157(78.1%) By prescription 44(21.9%) 8 For what purpose administered anthelmintic to your horse General diseases condition 117(58.2%) Abdominal problem 64(31.7%) Inappetence 20(9.9%) 9 Frequency of administered anthelmintic to horses Every two month 100(49.7%) Every six month 64(31.8%) Every year 22(10.5%) Never once 15(7.5%) 3.2. Mean Faecal Egg Counts and Percentage Reduction of Faecal Egg Counts The percentage reduction of fecal egg count for Ivermectin and Fenbendazole was 94.0% and 99.6%, for cart horses, respectively. Although Ivermectin had a fecal egg count reduction percentage of less than 95%, the lower confidence limit of 95% is greater than 90%. Based on the results, it can be concluded that Ivermectin is suspected to be associated with the development of resistance to gastrointestinal nematode parasites. From the analysis of a percentage reduction of fecal egg counts, fenbendazole was found to be effective. Because the faecal egg count reduction for Fenbendazole was greater than 95%, and its lower 95% confidence limit was above 90%, the drug was considered fully effective. Whereas, in the case of the packing horse, the percentage reduction of fecal egg counts for Ivermectin and Fenbendazole was 100% and 100%, respectively. From the analysis of a percentage reduction of fecal egg counts, both Ivermectin and Fenbendazole were found to be fully effective. Because the result of the fecal egg count reduction for Ivermectin and Fenbendazole was greater than 95%, and the lower confidence limit 95% of these anthelmintics was greater than 90%. From the analysis, the mean FEC between groups (treated and control non-treated) was not significantly different (P > 0.05) before treatment (day zero). On day 14, post-treatment egg counts and percentage reduction of FEC or FEC were significantly different (P < 0.05) between groups (treated and control non-treated). Fenbendazole-treated horses recorded significantly (P < 0.05) lower mean egg count than ivermectin-treated and untreated control groups of horses. Ivermectin-treated horses also showed significantly (P < 0.05) lower egg output than untreated groups after treatment.in (Table 3 ). Table 3 The Mean EPG and percentage of Fecal Egg Reduction test (FERCT) in both carts and packing horses Animal groups Treatment No. animal Mean EPG %FEC R 95%CI Pre-treatment ± SD Post-treatment ± SD LCL UCL Cart horses Ivermectin 10 5850 ± 2966.6 350 ± 278.8 a 94.01 90.9 97.8 Fenbendazole 10 6480 ± 3866.5 20 ± 34.9 b 99.60 99.4 100.06 Control 10 6490 ± 2352.3 6500 ± 2271.9 c NA NA NA Packing horses Ivermectin 10 8110 ± 4594.8 0 ± 0.00 d 100 - - Fenbendazole 10 7025 ± 3705.7 0 ± 0.00 e 100 - - Control 10 7050 ± 4344.9 7295 ± 4332.6 f NA NA NA SD: standard deviation, NA: not applicable, a, b, c, d, e, f Statistically different at P < 0.05. 3.3. Results of Larvascope by Modified Baermann Techniques The fecal culture of eggs for third-stage larvae was undertaken in parallel to fecal egg counting to differentiate the genus/species of nematodes before and after treatment in each anthelmintic treatment and the control group. Overall, the parasite genera/species identified (but not quantified) before treatment, irrespective of a group, were Cyathostomum spp, Strongyles (Strongylus vulgaris, Strongylus edentates and Strongylus equinus ), Oxyuris equi , and Parascaris equroum . But, Cyathostomum spp, Strongylus vulgaris , and Strongylus equinus were observed after treatment with Ivermectin or with suspects of Ivermectin resistance in (Fig. 3 ). 3.4. Results of Egg Reappearance Period Fecal egg counts of the samples taken on day 42 yielded the following results: from 10 horses, 4(40%) showed a negative EPG count, and 6(60%) showed a positive egg count for post-treatment of Ivermectin and for Fenbendazole 7(70%) showed a negative EPG count, and 3(30%) showed a positive egg count. At six weeks post treatment with Ivermectin and Fenbendazole, the mean FECR were (97.7%) and (99.2%) respectively. The % of FECR difference between pre-treatment and post-treatment of Ivermectin was 2.3%, and Fenbendazole was 0.8%. The mean of EPG on day 42 was 180 from Ivermectin treated horse and 50 from Fenbendazole treated horse. Therefore, long ERP (time to first positive fecal egg count) was observed for both Ivermectin and Fenbendazole in (Table 4 ). Table 4 Results of Egg Reappearance Period No. horse (positive) Types of treatment Pre-treatment (mean of E PG) Days after treatments with mean of EPG and (%FECR) % difference b/n pre and post FECR (%) Day 0 14 21 28 35 42 10(6) Ivermectin 8110 0(100) 0(100) 0(100) 0(100) 180(97) 2.3% 10(3) Fenbendazole 7025 0(100) 0(100) 0(100) 0(100) 50(99.2) 0.8% 4. Discussions The result of the questionnaire survey in this study focused on probing parasite control and management practices of horse owners. The majority (47.3%) of the respondents were managing their horses extensively, which agreed with the findings of [ 46 , 47 , 48 , 49 ]. In this study, the majority of respondents (67.7%) indicated that they have been administering anthelmintics to their horse through a veterinarian’s prescription, which agrees with previous work by [ 50 ] in Denmark and [ 51 ] in Denmark. The weights of horses were usually evaluated by visual estimation (78.1%). Given this possible bias, this practice may be a cause of the incorrect dosage of anthelmintics, which may lead to reduced anthelmintic efficacy. This finding agrees with the report of [ 46 , 49 , 52 ]. Ivermectin (63.2%) was the most widely-used anthelmintic, followed by Fenbendazole (31.8%). This study was in agreement with reports of [ 50 ] in Denmark, and [ 52 ] in Ireland. This was due to easy availability in the area and a lower price as compared to other anthelmintics. The present result showed that the mean FECRT values of Ivermectin for cart horse and packing horse were 94.01% and 100%, respectively. The resistance suspicion of the GIT nematode observed in the present study on Ivermectin might be due to the prolonged, frequent, repeated usage and improper dosage. This result was in agreement with the previous study done in Germany ([53] and in the USA [ 41 ]. They reported that the reduction of activity of Ivermectin against nematode parasites seems to be due to the survival of some of the luminal immature stages in the large intestines after treatment. However, this result was inconsistent with the study in Greece [ 54 ] and in Ethiopia [ 49 ]. This was because the monitoring activity applied to the efficacy of Ivermectin against intestinal nematodes was very high. Moreover, the faecal egg count reduction percentage of ivermectin on packing horses was (100%). Ivermectin was effective against the gastrointestinal nematode parasite of the packing horse. This was due to the extensively managed farm horses, which were not dewormed repeatedly, or dewormed once a year, or never. This study was in agreement with the previous study of (100%) around Hosanna [ 55 ] and (97.2%) around Gondar town [ 49 ]. The present study was in contrast with the study done in Germany [53] and in the USA [ 41 ]. In the present study, carried out on cart horses and packing horses, showed the effectiveness of Fenbendazole against nematodes parasite were (99.6%) and (100%), respectively. Hence, the result indicated that Fenbendazole was fully effective in both packing and cart of horses due to less frequent use and low availability in the study area. This study was in agreement with a study of (99.49%) in Romania [56] and in Ethiopia [ 55 ]. They reported that horses have been dewormed once per year or less or never. This may probably be the reason why the resistance against anthelmintics was not found in these studies. However, the current study was in contrast to studies done in Ethiopia [ 49 ] in Sweden [ 46 ] and in Romania [ 57 ]. There was not significantly different (P > 0.05) between groups (treated and non-treated) on day zero in both (cart horse and packing horse). However, on day 14, post-treatment egg counts and percentage reduction of FEC were significantly different (P < 0.05) between treated groups and control groups. This was in agreement with [ 55 ] around Hoseana and [ 49 ] around Gondar. In the present study, the nematode genera identified after treatment were similar to those found by other Ethiopian-based studies and studies conducted worldwide based on characteristics of nematode eggs. Strongylus vulgaris, Strongylus equinus, and Cyathostomum species were the only nematodes that remained post-treatment with reduced efficacy of ivermectin. This finding supports previous reports of [ 58 ] in Cambridge. This finding is also consistent with that of [ 37 ] from Brazil, [ 38 ] from the United States, and [ 59 ] from Ethiopia. Sangster [ 39 ] suggested that a reduction (shorter term) in the ERP of an anthelmintic is an early indicator of reduced efficacy, while a longer term will lead to efficacy. The current study showed the longer egg reappearance period following treatment with ivermectin and fenbendazole in the packing horse. This study was in agreement with previous reports of [ 60 ] in Germany. The current study was inconsistent with previous works done in Kentucky [ 61 ], in Italy [56], in the UK [ 62 ], and [53], which reported shorter egg reappearance. Reduced (shorter) ERPs have been associated with the survival of the luminal of fourth larval stages, which reach sexual maturity before the encysted fourth larval stage and/or newly ingested third larval stage. 5. Conclusion and Recommendations The current study demonstrated that gastrointestinal nematodes remain prevalent among horses in and around Tullu-Awuliya, with control efforts heavily reliant on two major anthelmintics: Ivermectin and Fenbendazole. Field evaluation using FECRT revealed that Fenbendazole maintained high efficacy (99.6%), whereas Ivermectin showed reduced effectiveness (94.01%), indicating suspected resistance. The detection of Strongylus vulgaris, Strongylus equinus , and Cyathostomum spp. in post treatment samples further supports emerging resistance to Ivermectin. ERP assessments in pack horses, however, showed no evidence of shortened intervals, suggesting no established resistance for either drug in this group. The questionnaire survey highlighted widespread use of Ivermectin and Fenbendazole, often without proper dosing or veterinary guidance. Overall, the findings underscore the need for improved helminth control strategies to delay further development of anthelmintic resistance. Based on the present study, the following recommendations were forwarded Adopt evidence-based deworming by integrating routine faecal egg count monitoring and FECRT to guide treatment decisions. Reduce indiscriminate anthelmintic use by promoting strategic, need-based deworming instead of frequent blanket treatments. Educate horse owners and local practitioners on correct dosing, drug rotation, and the risks of underdoing and misuse. Implement integrated parasite management strategies, including improved sanitation, grazing management, and minimizing pasture contamination. Conduct further longitudinal and molecular studies to confirm resistance patterns and identify factors influencing reduced drug efficacy in the region Declarations Acknowledgements Not applicable Authorship contribution statement Seid Kassaw: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Visualization, Writing– original draft and Writing– Review and editing. Alula Alemayehu Assen: Conceptualization, Methodology, Formal analysis, Writing– Review and Editing, Writing– original draft. Ahmed Yasine: Methodology, Supervision, Formal analysis, Writing– Review and Editing, Writing– original draft. Data availability The datasets for the current study are available from the corresponding author upon request. Conflicts of interest The authors declare that there is no known competing financial interest or personal relationship that could have appeared to influence the work reported in this paper. Ethical approval All research procedures involving animals, samples, or data were conducted in accordance with the relevant institutional Wollo University and international guidelines. Ethical approval was obtained from Wollo University, institutional research ethics review committee. Funding The authors did not receive support from any organization for the submitted work. Consent of participation and publication Not applicable References Andersen, U. V., Howe, D. K., Dangoudoubiyam, S., Toft, N., Reinemeyer, C. R., Lyons, E. T., Olsen, S. N., Monrad, J., Nejsum, P., & Nielsen, M. K. (2013). Strongylus vulgaris antigen with potential for pre-patent diagnosis . Parasites & Vectors, 6, 1–13. Wannas, H. Y., Dawood, K. H., & Gassem, G. H. (2012). Prevalence of gastrointestinal parasites in horses and donkeys in Al Diwaniyah Governorate, Al-Qadisiya. Journal of Veterinary Medical Science, 11 (1), 841–855. Martin, I. V., Verona, G. G., & Correia, T. R. (2009). Survey on control and management practices of equine helminth infections. Pesquisa Veterinária Brasileira, 29 (3), 253–257. Pereira, J. R., & Vianna, S. S. (2006). Gastrointestinal parasitic worms in equines in the Paraíba Valley, State of São Paulo, Brazil. Veterinary Parasitology , 289–295. Taylor, M. A., Coop, R. L., & Waller, L. (2007). Veterinary parasitology (3rd ed.). Blackwell Science. Zerihun, A., Bersisa, K., Bojia, E., Ayele, G., Tesfaye, M., & Etana, D. (2011). Endoparasites of donkeys in Sululta and Gefersa districts of central Oromia, Ethiopia. Journal of Animal and Veterinary Advances, 10 , 1850–1854. Alemayehu, R., & Etaferahu, Y. (2013). Gastrointestinal parasites of equines in South Wollo Zone, northeastern Ethiopia. Global Veterinaria, 11 (6), 824–830. Abebew, D., Bojia, E., & Ayele, G. (2011). Status of parasitism in donkeys of project and control areas in central Ethiopia: A comparative study. Ethiopian Veterinary Journal, 15 (2), 45–55. Getachew, M., Trawford, A., Feseha, G., & Reid, S. W. (2010). Gastrointestinal parasites of working donkeys in Ethiopia. Tropical Animal Health and Production, 42 (1), 27–33. Bath, E. H., & Malan, F. S. (1995). The FAMACHA ovine anemia guide . Livestock Health and Production Group of the South African Veterinary Association. Wolstenholme, A. J., Fairweather, I., Prichard, R., von Samson-Himmelstjerna, G., & Sangster, N. C. (2004). Drug resistance in veterinary helminths. Trends in Parasitology, 20 (10), 469–476. https://doi.org/10.1016/j.pt.2004.07.010 Matthews, J. B. (2014). Anthelmintic resistance in equine nematodes. International Journal for Parasitology: Drugs and Drug Resistance, 4 (3), 310–315. https://doi.org/10.1016/j.ijpddr.2014.10.003 Peregrine, A. S., Molento, M. B., Kaplan, R. M., & Nielsen, M. K. (2014). Anthelmintic resistance in important parasites of horses: Does it really matter? Veterinary Parasitology, 201 (1–2), 1–8. https://doi.org/10.1016/j.vetpar.2014.01.004 Scott, I., & Hodgkinson, J. E. (2015). An evidence-based approach to worm control. Equine Veterinary Education . Tzelos, T., & Matthews, J. B. (2016). Anthelmintic resistance in equine helminths and mitigating its effects. In Practice, 38 (10), 489–499. https://doi.org/10.1136/inp.i5287 Raza, A., Qamar, A. G., Hayat, K., Ashraf, S., & Williams, A. R. (2019). Anthelmintic resistance and novel control options in equine gastrointestinal nematodes. Parasitology, 146 , 425–437. https://doi.org/10.1017/S0031182018001786 James, C. E., Hudson, A. L., & Davey, M. W. (2009). Drug resistance mechanisms in helminths: Is it survival of the fittest? Trends in Parasitology, 25 , 328–335. Kaplan, R. M., & Nielsen, M. K. (2010). An evidence-based approach to equine parasite control: It ain’t the 60s anymore. Equine Veterinary Education, 22 (6), 306–316. https://doi.org/10.1111/j.2042-3292.2010.00084.x Ayele, G., Feseha, G., Bojia, E., & Joe, A. (2006). Prevalence of gastrointestinal parasites of donkeys in Dugda Bora District, Ethiopia. Livestock Research for Rural Development, 18 (11). http://www.cipav.org.co/lrrd/lrrd18/10/aye18136.htm Nuraddis, I., Tilahun, B., Benti, D., & Tadele, T. (2011). Survey of prevalence of helminth parasites of donkeys in and around Hawassa, Southern Ethiopia. Global Veterinaria, 6 (3), 223–227. Tihitna, S., Basaznew, B., Mersha, C., & Achenef, M. (2012). Occurrence of lungworm infection in equines and their associated risk factors. Global Veterinaria, 8 (1), 35–38. Yacob, H. T., & Ashenafi, H. (2013). Epidemiological study on gastrointestinal helminths of horses in Arsi Bale highlands of Oromia Region, Ethiopia. Ethiopian Veterinary Journal, 17 (2), 51–62. Tilahun, B., Nuraddis, I., Benti, D., & Tadele, T. (2014). Prevalence of helminth parasites of horses in and around Hawassa Town, Southern Ethiopia. Acta Parasitologica Globalis, 5 (1), 7–11. Asmare, K., Gelaye, E., & Ayelet, G. (2005). Anthelmintic resistance test in gastrointestinal nematodes of small ruminants in southern Ethiopia. Bulletin of Animal Health and Production in Africa, 53 , 89–95. Menkir, S. M., Sissay, M. M., Uggla, A., & Waller, P. J. (2006). Anthelmintic resistance of nematode parasites of small ruminants in eastern Ethiopia: Exploitation of refugia to restore anthelmintic efficacy. Veterinary Parasitology, 135 (3–4), 337–346. Svendsen, E. D. (1997). The professional handbook of the donkey (3rd ed.). Whittet Books. Reed, M. S., Bayly, M. W., & Sellon, C. D. (2004). Equine internal medicine . Elsevier Saunders. Reinemeyer, C. R., & Nielsen, M. K. (2014). Review of the biology and control of Oxyuris equi . Equine Veterinary Education, 26 , 584–591. Thrusfield, M. (2005). Veterinary epidemiology (3rd ed.). Blackwell Science Ltd. Arsham, H. (2002). Descriptive sampling data analysis: Statistical thinking for managerial decision making. http://home.ubalt.edu/ntsbarsh/Business-stat/opre504.htm Saari, S., Näreaho, A., & Nikander, S. E. (2018). Canine parasites and parasitic diseases . Academic Press. Lester, H. E., & Matthews, J. B. (2014). Faecal worm egg count analysis for targeting anthelmintic treatment in horses: Points to consider. Equine Veterinary Journal, 46 , 139–145. Coles, G. C., Bauer, C. F., & Borgsteede, H. M. (1992). World Association for the Advancement of Veterinary Parasitology (WAAVP) methods for the detection of anthelmintic resistance in nematodes of veterinary importance. Veterinary Parasitology, 44 (1–2), 35–44. Jørgensen, H., & Brian, P. (1994). The epidemiology, diagnosis and control of helminth parasites of ruminants . International Laboratory for Research on Animal Diseases (ILRAD). Wood, I. B., Amaral, N. K., Bairden, K., Duncan, J. L., Kassai, T., Malone, J. B., … Vercruysse, J. (1995). WAAVP guidelines for evaluating the efficacy of anthelmintics in ruminants (2nd ed.). Veterinary Parasitology, 58 (3), 181–213. https://doi.org/10.1016/0304-4017(95)00806-2 Murphy, L. M., Ehrlich, W. K., & Mayer, D. G. (2014). Anthelmintic resistance in ovine gastrointestinal nematodes in inland southern Queensland. Australian Veterinary Journal, 92 (11), 415–420. https://doi.org/10.1111/avj.12250 Ministry of Agriculture Fisheries and Food (MAFF). (1984). Manual of veterinary investigation laboratory techniques (Vol. 390). Bevilaqua, C. M. L., Rodrigues, M. D. L., & Concordet, D. (1993). Identification of infective larvae of some common nematode strongylids of horses. Revue de Médecine Vétérinaire, 144 (12), 989–995. Lichtenfels, J. R., Kharchenko, V. A., & Dvojnos, G. M. (2008). Illustrated identification keys to strongylid parasites of horses, zebras, and asses. Veterinary Parasitology, 156 , 4–161. Sangster, N. C. (1999). Pharmacology of anthelmintic resistance in cyathostomes. Veterinary Parasitology, 85 , 189–201. Nielsen, M. K. (2016). Equine tapeworm infection: Disease, diagnosis, and control. Equine Veterinary Education, 28 , 388–395. Lyons, E. T., Tolliver, S. C., Ionita, M., Lewellen, A., & Collins, S. S. (2008). Field studies indicating reduced activity of ivermectin on small strongyles. Parasitology Research, 103 (1), 209–215. Leathwick, D. M., & Hosking, B. C. (2009). Managing anthelmintic resistance: Modeling strategic use of a new anthelmintic class. New Zealand Veterinary Journal, 57 , 203–207. Nielsen, M. K., Reist, M., Kaplan, R. M., Pfister, K., van Doorn, D. C. K., & Becher, A. (2013). Equine parasite control under prescription-only conditions in Denmark. Veterinary Parasitology . https://doi.org/10.1016/j.vetpar.2013.10.016 Boersema, J. H., Eysker, M., Maas, J., & van der Aar, W. M. (1996). Comparison of the reappearance of strongyle eggs in foals, yearlings, and adults after treatment with ivermectin or pyrantel. Veterinary Quarterly, 18 , 7–9. IBM Corp. (2011). IBM SPSS Statistics for Windows (Version 20.0). IBM Corp. Lind, E. O., Uggla, A. E., Waller, P. J., Morrison, D. A., & Höglund, J. (2007). Parasite control practices on Swedish horse farms. Acta Veterinaria Scandinavica, 49 (25). Hinney, B., Wirtherle, N. C., Kyule, M., Miethe, N., Zessin, K. H., & Clausen, P. H. (2011). Questionnaire survey on helminth control on horse farms in Brandenburg, Germany. Parasitology Research, 109 (6), 1625–1635. Nielsen, M. K., Reist, M., Kaplan, R. M., Pfister, K., van Doorn, D. C., & Becher, A. (2014). Equine parasite control under prescription-only conditions in Denmark. Veterinary Parasitology, 204 (1–2), 64–72. Seyoum, Z., Zedwu, A., Dagnachew, S., & Bogale, B. (2017). Anthelmintic resistance of strongyle nematodes to ivermectin and fenbendazole in cart horses of Gondar. BioMed Research International, 2017 , 63–96. Nielsen, M. K., Haaning, N., & Olsen, S. N. (2006). Strongyle egg shedding consistency in horses under selective therapy. Veterinary Parasitology, 135 (3–4), 333–335. Nielsen, M. K., Reist, M., Kaplan, R. M., Pfister, K., van Doorn, D. C. K., & Becher, A. (2013). Equine parasite control in Denmark. Veterinary Parasitology . https://doi.org/10.1016/j.vetpar.2013.10.016 Elghryani, N., Duggan, V., Relf, V., & de Waal, T. (2019). Questionnaire survey on helminth control practices in horse farms in Ireland. Parasitology , 1–10. https://doi.org/10.1017/S0031182019000271 von Samson-Himmelstjerna, G., Fritzen, B., & Demeler, J. (2007). Reduced egg reappearance periods & Parascaris equorum drug failure. Veterinary Parasitology, 144 (1–2), 74–80. Papadopoulos, E., Hamhougias, K., Himonas, C., & Dorchies, P. H. (2000). Strongyle anthelmintic resistance in horses and cattle in Greece. Revue de Médecine Vétérinaire, 151 (12), 1139–1142. Feseha, H., Mesfin, M., & Friat, K. (2020). Anthelmintic efficacy of ivermectin and fenbendazole on working donkeys in Hosaena, Ethiopia. Veterinary Medicine International, 2020 , Article 4868797. Traversa, D., von Samson-Himmelstjerna, G., & Demeler, J. (2009). Anthelmintic resistance in cyathostomins from horse yards in Europe. Parasites & Vectors, 2 (2). Cernea, M., Cristina, R. T., Tefanut, L. C., de Carvalho, L. M. M., Taulescu, M. A., & Cozma, V. (2015). Screening for anthelmintic resistance in equid strongyles in Romania. Folia Parasitologica, 62 (1), 1–7. Molena, R. A., Peachey, L. E., Cesare, A., Traversa, D., & Cantacessi, C. (2018). Cyathostomine egg reappearance period after ivermectin in UK Thoroughbreds. Parasites & Vectors , 3–8. Abebe, B. G. (2015). Impact assessment of strategic mass deworming of donkeys in central Oromia, Ethiopia . Addis Ababa University. Fischer, J., Hinney, B., Zessin, K. H., von Samson-Himmelstjerna, G., & Clausen, P. H. (2015). Efficacy of selected anthelmintic drugs against cyathostomins in horses . ISBN 978-3-86387-618-0. Lyons, E., Tolliver, S., Collins, S., Ionita, M., Kuzmina, T., & Rossano, M. (2011). Reduced activity of ivermectin and moxidectin against small strongyles. Parasitology Research, 108 , 355–360. Relf, V. E., Lester, H. E., Morgan, E. R., Hodgkinson, J. E., & Matthews, J. B. (2014). Anthelmintic efficacy on UK Thoroughbred stud farms. International Journal for Parasitology, 44 , 507–514. Additional Declarations The authors declare no competing interests. Supplementary Files EggsofStrongyles.tif larva of horse nematodes Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8864548","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":590437865,"identity":"b3017f31-7d2d-4de1-8b37-eada15503e48","order_by":0,"name":"Seid 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17:19:22","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":true,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":true},"doi":"10.21203/rs.3.rs-8864548/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8864548/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102729745,"identity":"6014da95-0179-4640-b3d3-553c5593c3ba","added_by":"auto","created_at":"2026-02-16 04:20:23","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":127098,"visible":true,"origin":"","legend":"\u003cp\u003eStudy Area Map\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8864548/v1/b096ec4bd71c80582e81d9fc.png"},{"id":102729747,"identity":"17426891-d61a-41fe-91ad-5c0c0eed6dca","added_by":"auto","created_at":"2026-02-16 04:20:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":169650,"visible":true,"origin":"","legend":"\u003cp\u003eCommonly used and preferences of anthelmintic in the study area\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8864548/v1/a6ba83852494f3164113ec07.png"},{"id":102749235,"identity":"5ed944fa-78c7-4190-9e0d-318d6c414f0c","added_by":"auto","created_at":"2026-02-16 09:12:16","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":347228,"visible":true,"origin":"","legend":"\u003cp\u003eNematode parasites identified in association with suspected Ivermectin resistance in horses\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8864548/v1/8a3480448e07e3dfbac78447.png"},{"id":102751282,"identity":"ccaa9624-fe6d-47a9-81a4-6c2b08a12c9f","added_by":"auto","created_at":"2026-02-16 09:24:45","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1785844,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8864548/v1/b2c26907-fc22-416e-8527-d2874465651e.pdf"},{"id":102729748,"identity":"983f2f42-b48c-461b-b54d-4112cdd2524a","added_by":"auto","created_at":"2026-02-16 04:20:23","extension":"tif","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":591514,"visible":true,"origin":"","legend":"\u003cp\u003elarva of horse nematodes\u0026nbsp;\u003c/p\u003e","description":"","filename":"EggsofStrongyles.tif","url":"https://assets-eu.researchsquare.com/files/rs-8864548/v1/786aea05bd9ff9588c1e9539.tif"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eField Efficacy Evaluation of Commonly Used Anthelmintics Against Gastrointestinal Nematodes on Naturally Infected Horses in and around Tulu Awuliya Town, North East Ethiopia\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eGastrointestinal helminth infections remain one of the most significant constraints to profitable equine production worldwide, causing reduced performance, morbidity, and economic loss [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Equines are highly susceptible to a wide range of parasitic infections [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], and an apparently healthy horse may harbor hundreds of thousands of gastrointestinal helminths, including nematodes, cestodes, and trematodes [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Among these, gastrointestinal nematodes (GIN) such as Strongylidae, Spiruridae, Oxyuridae, Trichostrongylidae, Rhabditidae, and Ascaridae represent the most prevalent and economically important groups affecting horses [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn Ethiopia, several studies have reported a high burden of gastrointestinal nematodes in equines, with notable species including Strongyles (99.5%) and Parascaris equorum (53%) in Sululta and Gefersa by [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], Parascaris equorum (70.7%), Oxyuris equi (4.6%), and Dictyocaulus arnfieldi (22.6%) in Dessie and Kombolcha by [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], and Tridontophorus spp. (52.8%) in Dugda Bora by [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Additional reports from Dessie and Kombolcha indicated the presence of Strongyloides westeri (11%), while in Gonder town, cyathostomum spp. (99.5%) was detected, as documented by [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Together, these findings underscore the widespread distribution and high prevalence of diverse gastrointestinal nematodes in Ethiopian equine populations.\u003c/p\u003e \u003cp\u003eThe currently available tools for protecting equines from many gastrointestinal helminths depend mainly on using chemical treatments, namely anthelmintics, in many parts of the world. Chemical control through anthelmintics remains the primary strategy for managing equine helminths globally [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. The widespread availability and routine use of broad‑spectrum anthelmintics such as benzimidazoles (e.g., Fenbendazole) and macrocyclic lactones (e.g., Ivermectin) have improved parasite control but also accelerated the emergence of anthelmintic resistance [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Resistance develops when a proportion of the parasite population survives treatment and passes heritable resistance traits to subsequent generations [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Risk factors include frequent and repeated treatments, incorrect dosing, exclusive reliance on chemical control, and lack of integrated parasite‑management practices [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGlobally and in Ethiopia, the definition of resistance has been reported to be debated, as some consider it total anthelmintics' failure, while others define it as a decrease in efficacy, or perhaps when the maximum dose is no longer effective [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Standardized methods for detecting anthelmintic resistance include the Fecal Egg Count Reduction Test (FECRT), which evaluates the percentage reduction of fecal egg counts after treatment, and the Egg Reappearance Period (ERP), which measures how long after treatment parasite eggs reappear in feces, an important early indicator of developing resistance [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn Ethiopia, despite numerous studies documenting the prevalence of equine helminths [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, and \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], research on anthelmintic efficacy and resistance in horses is extremely limited, with most investigations focusing on ruminants. The situation is further complicated by the widespread misuse, illegal trade, and irrational administration of anthelmintics due to the absence of stringent national policies [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlthough gastrointestinal nematodes of horses are widely recognized in Ethiopia, no previous study has evaluated the field efficacy of commonly used anthelmintics (Fenbendazole and Ivermectin) against equine GIN in and around Tulu Awuliya town using both FECRT and ERP methods. In Tulu Awuliya town, Fenbendazole and Ivermectin are the most commonly used anthelmintics. However, horse owners frequently report reduced drug performance despite regular deworming practices. This suggests a possible decline in drug efficacy, yet no field‑based evaluation has been conducted in the area. Therefore, the present study was designed to evaluate the field efficacy of commonly used anthelmintics against gastrointestinal nematodes of naturally infected horses in and around Tulu Awuliya town and to assess the helminth‑control and anthelmintic‑use practices of horse owners in the study area.\u003c/p\u003e"},{"header":"2. MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e2.1. Study Area\u003c/h2\u003e\n \u003cp\u003eThe study was conducted from November 2020 to May 2021 in Tullu Awuliya, located in South Wollo, Northeast Ethiopia, approximately 501 km from Addis Ababa (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). The area lies at a latitude of 11\u0026deg;N and a longitude of 39\u0026deg;E, encompassing both highland and midland agro-ecological zones. Elevations range between 1,500 and 3,700 meters above sea level. According to the Legambo District Agricultural Extension Office (2019), the area experiences mean minimum and maximum temperatures of 16\u0026deg;C and 27\u0026deg;C, respectively, and an average annual rainfall of 933.9 mm. Agriculture in the district is predominantly cereal-based, with barley and wheat serving as major crops, and oxen and horses providing essential draught power for plowing. The main livestock species reared in the area include cattle, sheep, goats, horses, donkeys, mules, and poultry. Based on data from the Legambo Wereda Animal Resources Office (2020), the equine population comprises 26,639 donkeys, 10,584 horses, and 3,587 mules.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003e2.2. Study Animals\u003c/h2\u003e\n \u003cp\u003eThe study animals were horses managed under extensive and semi-intensive production systems and owned by local farmers. During sampling, information on each horse, including age, sex, working type, management system, and body condition, was recorded. Age was determined using dentition and owners\u0026rsquo; birth records following the method described by [\u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e], Based on this, horses were categorized into three age groups: young (\u0026lt;\u0026thinsp;3 years), adult (3\u0026ndash;10 years), and old (\u0026gt;\u0026thinsp;10 years). Body condition was categorized as poor, moderate, and good using visual appraisal and manual palpation of the spinous and transverse processes [27]. The study horses were all local breeds and were primarily used for human transportation and packing purposes.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003e2.3. Sample Size Determination\u003c/h2\u003e\n \u003cp\u003eThe sample size for fecal egg count (FEC) was determined according to [\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e], considering the expected prevalence of 70.4% [\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e], with 5% desired absolute precision. Hence, the sample size was estimated by substituting into the formula\u003c/p\u003e\n \u003cdiv id=\"Equa\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e$$\\:\\text{N}=\\frac{1.96\u0026sup2;Pexp(1-Pexp)}{d\u0026sup2;}$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003eWhere, N= sample size, Pexp\u0026thinsp;=\u0026thinsp;expected prevalence, d2\u0026thinsp;=\u0026thinsp;absolute precision\u003c/p\u003e\n \u003cp\u003eBased on the formula, the total sample was 320, but the sample size was increased to 520 horses in order to increase the chance of having enough horses with high fecal egg count for the experimental study and to reduce sampling error and subsequently increase the accuracy. The sample size for the questionnaire survey was determined using the formula (n\u0026thinsp;=\u0026thinsp;0.25/SE2) proposed by [\u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e] at a standard error (SE) of 0.05 with a 95% confidence interval. Based on the formula, the total number of respondents was 100. However, the number of respondents was increased to 201 to get more accurate data from the owners.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003e2.4. Study Design and Sampling techniques\u003c/h2\u003e\n \u003cp\u003eA field experimental study was conducted to evaluate the efficacy of commonly used anthelmintics against gastrointestinal nematodes in horses in Tulu Awuliya town. A total of 520 horses were randomly selected using a lottery method for parasitological screening and fecal egg count (FEC) assessment. Each horse was identified using the owner\u0026rsquo;s name identification system. Fecal samples collected from all study horses were examined using simple flotation and the modified McMaster technique [\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e]. Of the 520 horses examined, 374 were found to be naturally infected with GIT nematodes. From these infected horses, 60 were selected for the field experimental trial based on the criteria recommended by the World Association for the Advancement of Veterinary Parasitology (WAAVP). Inclusion criteria required horses to have a medium body condition, be adults, be managed under extensive husbandry, and not be treated with any anthelmintic in the preceding three months. Additionally, only male cart horses used for transportation and non‑pregnant female pack horses used for packing were included. All selected horses were required to have an FEC\u0026thinsp;\u0026ge;\u0026thinsp;150 eggs per gram (EPG) [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e]. The 60 horses were randomly allocated into six experimental groups (10 horses each): Ivermectin‑treated, Fenbendazole‑treated, and untreated control groups for both cart and pack horses. Horses were treated according to manufacturer‑recommended doses using Fenbendazole (2400 mg, Rangfebenda 20FB0404) or Ivermectin 1% (Ivertor 201001) in (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eExperimental layout\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroups\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTreatment\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDescription of drugs\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eG\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCart horses Treated with Ivermectin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIvermectin 1%, 0.2 mg/kg Po, Ivertor Habei Chengshengtang Animal Pharmaceuticals Co., Ltd/China Batch No.201001 and Exp date, 10/2023\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eG\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCart horses Treated with Fenbendazole\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFenbendazole 2400 mg, 7.5 mg /kg with grain Rangfebenda, Chenqdu Qiankun Veterinary Pharmaceuticals Co., Ltd./ China Batch No. 20FB0404 and exp. date, 10/2023\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eG\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCart horses - Un treated\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eG\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e4\u003c/strong\u003e\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePack horses Treated with Ivermectin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIvermectin 1%, 0.2 mg/kg Po, Ivertor Habei Chengshengtang Animal Pharmaceuticals Co., Ltd/China Batch No.201001 and Exp date, 10/2023\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eG\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePack horses Treated with Fenbendazole\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFenbendazole 2400 mg, 7.5 mg /kg with grain Rangfebenda, Chenqdu Qiankun Veterinary Pharmaceuticals Co., Ltd./ China Batch No. 20FB0404 and exp. date, 10/2023\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eG\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e6\u003c/strong\u003e\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePack horses - Un treated\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003ch2\u003e2.5. Data Collection Methods\u003c/h2\u003e\n \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.1. Questionnaire survey\u003c/h2\u003e\n \u003cp\u003eA structured questionnaire was prepared and translated into the local language of the respondents (Amharic) and pretested before the commencement of the study. A total of 201 horse owners were randomly selected and interviewed in order to collect information on the anthelmintic utilization and helminth control practices. The respondents were horse owners whose horses were included or selected for the preliminary screening test by fecal examination and FEC determination. The questionnaire focused mainly on information on the commonly used anthelmintics, the frequency of use, criteria for selection, and the main source of the anthelmintics, the management system, and observations on the responses after treatment (efficacy).\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.2. Faecal sample collection and examination\u003c/h2\u003e\n \u003cp\u003eFecal samples were collected directly from the rectum using clean gloves for screening and fecal egg count (FEC) analysis. During sampling, sampling date, body condition, working type, age, sex, management system, and owner identity were recorded for each horse. For the experimental study, fecal samples were collected per rectum before treatment (day 0) and after treatment (day 14). Each sample was placed in a properly labeled container and transported in an ice box to the Parasitology Laboratory of Wollo University, Faculty of Veterinary Medicine, and the Akesta Animal Health Clinic Laboratory. Samples were stored at +\u0026thinsp;4\u0026deg;C when immediate processing was not possible, and all were processed within 48 hours. Parasitological examination involved both qualitative and quantitative techniques. Simple flotation was used to detect gastrointestinal nematode eggs, while the modified McMaster method was employed to determine FEC and assess infection intensity [\u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e]. For flotation, 3 g of feces were mixed with 45 ml of saturated NaCl solution, strained, centrifuged, and topped with flotation fluid to create a reverse meniscus before placing a coverslip for microscopic examination. For the modified McMaster technique, 3 g of feces were mixed with 42 ml of saturated NaCl, strained, centrifuged, and the mixture was used to fill the McMaster counting chamber, after which eggs per gram of feces were counted [\u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e]. Anthelmintic efficacy was evaluated using the fecal egg count reduction test (FECRT), following standard procedures described by [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.3. Faecal egg count reduction test (FECR)\u003c/h2\u003e\n \u003cp\u003eThe fecal egg count reduction test was used for the evaluation of anthelmintic efficacy. The efficacy of the anthelmintics was tested according to the World Association for the Advancement of Veterinary Parasitology (WAAVP) recommendations for the detection of anthelmintic efficacy in horses by the percentage reduction of mean egg excretion on the 14th day post treatment [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e]. The efficacy was calculated by comparing the arithmetic mean of egg counts 14 days post-treatment to those of day 0 using the formula.\u003c/p\u003e\n \u003cp\u003e\u003cimg 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\"\u003e\u003c/p\u003e\n \u003cp\u003eWhen the percentage reduction of EPG was equal to or more than 95%, and the lower 95% CI was equal to or more than 90%, the anthelmintic was considered effective. Resistance to an anthelmintic is considered to be present if the value of the FECR percentage is less than 95% and the lower confidence limit of the confidence interval is less than 90%. If only one of these criteria is met, anthelmintic resistance is suspected [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e34\u003c/span\u003e, and \u003cspan class=\"CitationRef\"\u003e35\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.4. Larvascopy\u003c/h2\u003e\n \u003cp\u003eA modified Baermann technique was used to isolate the 3rd larvae stage of nematode parasites from fecal cultures. In the current study, fecal culture of eggs of third-stage larvae was undertaken along with the fecal egg counting to differentiate the genus or species of GIT nematodes before treatment on day 0 and after treatment on day 14 in each anthelmintic treatment and the control groups. Fecal samples containing nematode eggs from each group of horses were pooled, finely crushed using a mortar and pestle, and cultured in Petridish. A small amount of water was added to moisten the fecal sample, and incubated at 27 oC for 10 days and mixed periodically. Then, the larvae were recovered using a modified Baermann technique [\u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e]. After collection of the larvae, a drop of the sample was mounted on a microscopic slide, killed with Lugol\u0026rsquo;s iodine, and identified at the genus/species level in each group based on morphological characteristics as described previously [\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.5. Egg reappearance period (ERP)\u003c/h2\u003e\n \u003cp\u003eEgg reappearance period (ERP) is the amount of time it takes for parasite eggs to begin recurring in the feces following anthelmintic treatment [\u003cspan class=\"CitationRef\"\u003e39\u003c/span\u003e]. The egg reappearance period was used for the detection of anthelmintic efficacy when initial efficacy was 100% (egg disappearance) [\u003cspan class=\"CitationRef\"\u003e40\u003c/span\u003e]. It was described by using three important parameters: (1) the first time a positive fecal egg count was recorded as post treatment [\u003cspan class=\"CitationRef\"\u003e41\u003c/span\u003e], (2) 10% of the Day 0 value [\u003cspan class=\"CitationRef\"\u003e42\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e43\u003c/span\u003e]. These parameters were fulfilled, indicating shorter egg reappearance, which leads to a reduction in the efficacy of anthelmintics [\u003cspan class=\"CitationRef\"\u003e44\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003e2.6. Data Management and Analysis\u003c/h2\u003e\n \u003cp\u003eData were collected and stored in Microsoft Excel, analyzed using SPSS V-20 statistical software [\u003cspan class=\"CitationRef\"\u003e45\u003c/span\u003e]. The preliminary data of helminth infection and questionnaire data were analyzed using descriptive statistics to compute the frequency and percentages. A P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was used to determine the level of significance. One-way ANOVA was used to compare the mean number of eggs per gram of each experimental group. The effectiveness of each anthelmintic was evaluated by computing the mean of fecal egg count reduction (FECRT) for each treatment group.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"3. RESULTS","content":"\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Questionnaire Survey on Horse Owners\u0026rsquo; Helminth Control Practices and Anthelmintic Use\u003c/h2\u003e \u003cp\u003eA majority (62.7%) indicated that veterinary services were sufficient, and 70.1% reported using anthelmintics for their horses. Ivermectin was the most frequently used drug (63.2%), followed by Fenbendazole (31.8%), and while 5.0% used both, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA. The main reasons for drug preference were accessibility (56.7%), price (28.9%), and ease of use (14.4%), Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB. Government veterinary clinics were the predominant drug source (65.1%), with private clinics (20.9%), open markets (8%), and illegal sellers (6%) also contributing. Most treatments were administered by government veterinarians (67.7%), though a smaller proportion relied on private veterinarians (10.3%). Body weight estimation before dosing was commonly done by eye (78.1%), while only 21.9% used prescription‑based estimation. Anthelmintics were mainly administered for general disease conditions (58.2%), abdominal problems (31.7%), and inappetence (9.9%). Regarding treatment frequency, 49.7% dewormed their horses every two months, 31.8% every six months, 10.5% annually, and 7.5% had never dewormed their horses in (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSummary of horse owners\u0026rsquo; helminth control practices and anthelmintic use in the study area\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS. No.\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eResponse\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFrequency (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eThere are sufficient veterinary services\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e126(62.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e75(37.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eUse of anthelmintic to treat your horses\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e141(70.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e60(29.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eMost commonly used anthelmintic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eIvermectin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e127(63.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFenbendazole\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e64(31.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBoth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10(5.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eThe reason behind preference of anthelmintic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAccessibility\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e114(56,7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eConsiderable price\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e58(28.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eComfortability to use\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29(14.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003eThe common sources of anthelmintic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGovernmental clinic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e131(65.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePrivate clinic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42(20.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOpen market\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16(8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eIllegal sellers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12(6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eWho prescribing and administering anthelmintic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBy governmental veterinarian\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e136(67.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBy Private veterinarian\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e49(10.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eHow to estimate your horse body weight During administration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBy others person\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4(2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBy eye estimation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e157(78.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBy prescription\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44(21.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eFor what purpose administered anthelmintic to your horse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGeneral diseases condition\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e117(58.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAbdominal problem\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e64(31.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInappetence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20(9.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003eFrequency of administered anthelmintic to horses\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEvery two month\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100(49.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEvery six month\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e64(31.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEvery year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22(10.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNever once\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15(7.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Mean Faecal Egg Counts and Percentage Reduction of Faecal Egg Counts\u003c/h2\u003e \u003cp\u003eThe percentage reduction of fecal egg count for Ivermectin and Fenbendazole was 94.0% and 99.6%, for cart horses, respectively. Although Ivermectin had a fecal egg count reduction percentage of less than 95%, the lower confidence limit of 95% is greater than 90%. Based on the results, it can be concluded that Ivermectin is suspected to be associated with the development of resistance to gastrointestinal nematode parasites. From the analysis of a percentage reduction of fecal egg counts, fenbendazole was found to be effective. Because the faecal egg count reduction for Fenbendazole was greater than 95%, and its lower 95% confidence limit was above 90%, the drug was considered fully effective. Whereas, in the case of the packing horse, the percentage reduction of fecal egg counts for Ivermectin and Fenbendazole was 100% and 100%, respectively. From the analysis of a percentage reduction of fecal egg counts, both Ivermectin and Fenbendazole were found to be fully effective. Because the result of the fecal egg count reduction for Ivermectin and Fenbendazole was greater than 95%, and the lower confidence limit 95% of these anthelmintics was greater than 90%. From the analysis, the mean FEC between groups (treated and control non-treated) was not significantly different (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) before treatment (day zero). On day 14, post-treatment egg counts and percentage reduction of FEC or FEC were significantly different (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) between groups (treated and control non-treated). Fenbendazole-treated horses recorded significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) lower mean egg count than ivermectin-treated and untreated control groups of horses. Ivermectin-treated horses also showed significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) lower egg output than untreated groups after treatment.in (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe Mean EPG and percentage of Fecal Egg Reduction test (FERCT) in both carts and packing horses\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAnimal groups\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eNo. animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eMean EPG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e%FEC R\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e95%CI\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-treatment\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePost-treatment\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLCL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eUCL\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCart horses\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIvermectin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5850\u0026thinsp;\u0026plusmn;\u0026thinsp;2966.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e350\u0026thinsp;\u0026plusmn;\u0026thinsp;278.8\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e94.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e90.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e97.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFenbendazole\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6480\u0026thinsp;\u0026plusmn;\u0026thinsp;3866.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20\u0026thinsp;\u0026plusmn;\u0026thinsp;34.9\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e99.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e99.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e100.06\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6490\u0026thinsp;\u0026plusmn;\u0026thinsp;2352.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6500\u0026thinsp;\u0026plusmn;\u0026thinsp;2271.9\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePacking horses\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIvermectin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8110\u0026thinsp;\u0026plusmn;\u0026thinsp;4594.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFenbendazole\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7025\u0026thinsp;\u0026plusmn;\u0026thinsp;3705.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00\u003csup\u003ee\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7050\u0026thinsp;\u0026plusmn;\u0026thinsp;4344.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7295\u0026thinsp;\u0026plusmn;\u0026thinsp;4332.6\u003csup\u003ef\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eSD: standard deviation, NA: not applicable, \u003csup\u003e\u003cb\u003ea, b, c, d, e, f\u003c/b\u003e\u003c/sup\u003e Statistically different at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Results of Larvascope by Modified Baermann Techniques\u003c/h2\u003e \u003cp\u003eThe fecal culture of eggs for third-stage larvae was undertaken in parallel to fecal egg counting to differentiate the genus/species of nematodes before and after treatment in each anthelmintic treatment and the control group. Overall, the parasite genera/species identified (but not quantified) before treatment, irrespective of a group, were \u003cem\u003eCyathostomum\u003c/em\u003e spp, \u003cem\u003eStrongyles (Strongylus vulgaris, Strongylus edentates\u003c/em\u003e and \u003cem\u003eStrongylus equinus\u003c/em\u003e), \u003cem\u003eOxyuris equi\u003c/em\u003e, and \u003cem\u003eParascaris equroum\u003c/em\u003e. But, \u003cem\u003eCyathostomum\u003c/em\u003e spp, \u003cem\u003eStrongylus vulgaris\u003c/em\u003e, and \u003cem\u003eStrongylus equinus\u003c/em\u003e were observed after treatment with Ivermectin or with suspects of Ivermectin resistance in (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003e3.4. Results of Egg Reappearance Period\u003c/h2\u003e \u003cp\u003eFecal egg counts of the samples taken on day 42 yielded the following results: from 10 horses, 4(40%) showed a negative EPG count, and 6(60%) showed a positive egg count for post-treatment of Ivermectin and for Fenbendazole 7(70%) showed a negative EPG count, and 3(30%) showed a positive egg count. At six weeks post treatment with Ivermectin and Fenbendazole, the mean FECR were (97.7%) and (99.2%) respectively. The % of FECR difference between pre-treatment and post-treatment of Ivermectin was 2.3%, and Fenbendazole was 0.8%. The mean of EPG on day 42 was 180 from Ivermectin treated horse and 50 from Fenbendazole treated horse. Therefore, long ERP (time to first positive fecal egg count) was observed for both Ivermectin and Fenbendazole in (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of Egg Reappearance Period\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. horse (positive)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTypes of treatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePre-treatment (mean of E\u003c/p\u003e \u003cp\u003ePG)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c8\" namest=\"c4\"\u003e \u003cp\u003eDays after treatments with mean of EPG and (%FECR)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e% difference b/n pre and post FECR (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDay 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10(6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIvermectin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8110\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e180(97)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.3%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10(3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFenbendazole\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7025\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e50(99.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.8%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Discussions","content":"\u003cp\u003eThe result of the questionnaire survey in this study focused on probing parasite control and management practices of horse owners. The majority (47.3%) of the respondents were managing their horses extensively, which agreed with the findings of [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e47\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e48\u003c/span\u003e, \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. In this study, the majority of respondents (67.7%) indicated that they have been administering anthelmintics to their horse through a veterinarian\u0026rsquo;s prescription, which agrees with previous work by [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e50\u003c/span\u003e] in Denmark and [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e51\u003c/span\u003e] in Denmark. The weights of horses were usually evaluated by visual estimation (78.1%). Given this possible bias, this practice may be a cause of the incorrect dosage of anthelmintics, which may lead to reduced anthelmintic efficacy. This finding agrees with the report of [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e49\u003c/span\u003e, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. Ivermectin (63.2%) was the most widely-used anthelmintic, followed by Fenbendazole (31.8%). This study was in agreement with reports of [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e50\u003c/span\u003e] in Denmark, and [\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e52\u003c/span\u003e] in Ireland. This was due to easy availability in the area and a lower price as compared to other anthelmintics.\u003c/p\u003e \u003cp\u003eThe present result showed that the mean FECRT values of Ivermectin for cart horse and packing horse were 94.01% and 100%, respectively. The resistance suspicion of the GIT nematode observed in the present study on Ivermectin might be due to the prolonged, frequent, repeated usage and improper dosage. This result was in agreement with the previous study done in Germany ([53] and in the USA [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. They reported that the reduction of activity of Ivermectin against nematode parasites seems to be due to the survival of some of the luminal immature stages in the large intestines after treatment. However, this result was inconsistent with the study in Greece [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e54\u003c/span\u003e] and in Ethiopia [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. This was because the monitoring activity applied to the efficacy of Ivermectin against intestinal nematodes was very high. Moreover, the faecal egg count reduction percentage of ivermectin on packing horses was (100%). Ivermectin was effective against the gastrointestinal nematode parasite of the packing horse. This was due to the extensively managed farm horses, which were not dewormed repeatedly, or dewormed once a year, or never. This study was in agreement with the previous study of (100%) around Hosanna [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e] and (97.2%) around Gondar town [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. The present study was in contrast with the study done in Germany [53] and in the USA [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e41\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn the present study, carried out on cart horses and packing horses, showed the effectiveness of Fenbendazole against nematodes parasite were (99.6%) and (100%), respectively. Hence, the result indicated that Fenbendazole was fully effective in both packing and cart of horses due to less frequent use and low availability in the study area. This study was in agreement with a study of (99.49%) in Romania [56] and in Ethiopia [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]. They reported that horses have been dewormed once per year or less or never. This may probably be the reason why the resistance against anthelmintics was not found in these studies. However, the current study was in contrast to studies done in Ethiopia [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e49\u003c/span\u003e] in Sweden [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e46\u003c/span\u003e] and in Romania [\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e57\u003c/span\u003e]. There was not significantly different (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) between groups (treated and non-treated) on day zero in both (cart horse and packing horse). However, on day 14, post-treatment egg counts and percentage reduction of FEC were significantly different (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) between treated groups and control groups. This was in agreement with [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e] around Hoseana and [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e49\u003c/span\u003e] around Gondar.\u003c/p\u003e \u003cp\u003eIn the present study, the nematode genera identified after treatment were similar to those found by other Ethiopian-based studies and studies conducted worldwide based on characteristics of nematode eggs. Strongylus vulgaris, Strongylus equinus, and Cyathostomum species were the only nematodes that remained post-treatment with reduced efficacy of ivermectin. This finding supports previous reports of [\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e58\u003c/span\u003e] in Cambridge. This finding is also consistent with that of [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e37\u003c/span\u003e] from Brazil, [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e38\u003c/span\u003e] from the United States, and [\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e59\u003c/span\u003e] from Ethiopia.\u003c/p\u003e \u003cp\u003eSangster [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e39\u003c/span\u003e] suggested that a reduction (shorter term) in the ERP of an anthelmintic is an early indicator of reduced efficacy, while a longer term will lead to efficacy. The current study showed the longer egg reappearance period following treatment with ivermectin and fenbendazole in the packing horse. This study was in agreement with previous reports of [\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e60\u003c/span\u003e] in Germany. The current study was inconsistent with previous works done in Kentucky [\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e61\u003c/span\u003e], in Italy [56], in the UK [\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e62\u003c/span\u003e], and [53], which reported shorter egg reappearance. Reduced (shorter) ERPs have been associated with the survival of the luminal of fourth larval stages, which reach sexual maturity before the encysted fourth larval stage and/or newly ingested third larval stage.\u003c/p\u003e"},{"header":"5. Conclusion and Recommendations","content":"\u003cp\u003eThe current study demonstrated that gastrointestinal nematodes remain prevalent among horses in and around Tullu-Awuliya, with control efforts heavily reliant on two major anthelmintics: Ivermectin and Fenbendazole. Field evaluation using FECRT revealed that Fenbendazole maintained high efficacy (99.6%), whereas Ivermectin showed reduced effectiveness (94.01%), indicating suspected resistance. The detection of \u003cem\u003eStrongylus vulgaris, Strongylus equinus\u003c/em\u003e, and \u003cem\u003eCyathostomum\u003c/em\u003e spp. in post treatment samples further supports emerging resistance to Ivermectin. ERP assessments in pack horses, however, showed no evidence of shortened intervals, suggesting no established resistance for either drug in this group. The questionnaire survey highlighted widespread use of Ivermectin and Fenbendazole, often without proper dosing or veterinary guidance. Overall, the findings underscore the need for improved helminth control strategies to delay further development of anthelmintic resistance.\u003c/p\u003e \u003cp\u003eBased on the present study, the following recommendations were forwarded\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eAdopt evidence-based deworming by integrating routine faecal egg count monitoring and FECRT to guide treatment decisions.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eReduce indiscriminate anthelmintic use by promoting strategic, need-based deworming instead of frequent blanket treatments.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eEducate horse owners and local practitioners on correct dosing, drug rotation, and the risks of underdoing and misuse.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eImplement integrated parasite management strategies, including improved sanitation, grazing management, and minimizing pasture contamination.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eConduct further longitudinal and molecular studies to confirm resistance patterns and identify factors influencing reduced drug efficacy in the region\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthorship contribution statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSeid Kassaw: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Visualization, Writing\u0026ndash; original draft and Writing\u0026ndash; Review and editing. \u0026nbsp;Alula Alemayehu Assen: Conceptualization, Methodology, Formal analysis, Writing\u0026ndash; Review and Editing, Writing\u0026ndash; original draft. Ahmed Yasine: Methodology, Supervision, Formal analysis, Writing\u0026ndash; Review and Editing, Writing\u0026ndash; original draft.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets for the current study are available from the corresponding author upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that there is no known competing financial interest or personal relationship that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll research procedures involving animals, samples, or data were conducted in accordance with the relevant institutional Wollo University and international guidelines. Ethical approval was obtained from Wollo University, institutional research ethics review committee.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors did not receive support from any organization for the submitted work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent of participation and publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAndersen, U. V., Howe, D. K., Dangoudoubiyam, S., Toft, N., Reinemeyer, C. R., Lyons, E. T., Olsen, S. N., Monrad, J., Nejsum, P., \u0026amp; Nielsen, M. K. (2013). \u003cem\u003eStrongylus vulgaris antigen with potential for pre-patent diagnosis\u003c/em\u003e. Parasites \u0026amp; Vectors, 6, 1\u0026ndash;13.\u003c/li\u003e\n \u003cli\u003eWannas, H. Y., Dawood, K. H., \u0026amp; Gassem, G. H. (2012). Prevalence of gastrointestinal parasites in horses and donkeys in Al Diwaniyah Governorate, Al-Qadisiya. \u003cem\u003eJournal of Veterinary Medical Science, 11\u003c/em\u003e(1), 841\u0026ndash;855.\u003c/li\u003e\n \u003cli\u003eMartin, I. V., Verona, G. G., \u0026amp; Correia, T. R. (2009). Survey on control and management practices of equine helminth infections. \u003cem\u003ePesquisa Veterin\u0026aacute;ria Brasileira, 29\u003c/em\u003e(3), 253\u0026ndash;257.\u003c/li\u003e\n \u003cli\u003ePereira, J. R., \u0026amp; Vianna, S. S. (2006). Gastrointestinal parasitic worms in equines in the Para\u0026iacute;ba Valley, State of S\u0026atilde;o Paulo, Brazil. \u003cem\u003eVeterinary Parasitology\u003c/em\u003e, 289\u0026ndash;295.\u003c/li\u003e\n \u003cli\u003eTaylor, M. A., Coop, R. L., \u0026amp; Waller, L. (2007). \u003cem\u003eVeterinary parasitology\u003c/em\u003e (3rd ed.). Blackwell Science.\u003c/li\u003e\n \u003cli\u003eZerihun, A., Bersisa, K., Bojia, E., Ayele, G., Tesfaye, M., \u0026amp; Etana, D. (2011). Endoparasites of donkeys in Sululta and Gefersa districts of central Oromia, Ethiopia. \u003cem\u003eJournal of Animal and Veterinary Advances, 10\u003c/em\u003e, 1850\u0026ndash;1854.\u003c/li\u003e\n \u003cli\u003eAlemayehu, R., \u0026amp; Etaferahu, Y. (2013). Gastrointestinal parasites of equines in South Wollo Zone, northeastern Ethiopia. \u003cem\u003eGlobal Veterinaria, 11\u003c/em\u003e(6), 824\u0026ndash;830.\u003c/li\u003e\n \u003cli\u003eAbebew, D., Bojia, E., \u0026amp; Ayele, G. (2011). Status of parasitism in donkeys of project and control areas in central Ethiopia: A comparative study. \u003cem\u003eEthiopian Veterinary Journal, 15\u003c/em\u003e(2), 45\u0026ndash;55.\u003c/li\u003e\n \u003cli\u003eGetachew, M., Trawford, A., Feseha, G., \u0026amp; Reid, S. W. (2010). Gastrointestinal parasites of working donkeys in Ethiopia. \u003cem\u003eTropical Animal Health and Production, 42\u003c/em\u003e(1), 27\u0026ndash;33.\u003c/li\u003e\n \u003cli\u003eBath, E. H., \u0026amp; Malan, F. S. (1995).\u0026nbsp;\u003cem\u003eThe FAMACHA ovine anemia guide\u003c/em\u003e. Livestock Health and Production Group of the South African Veterinary Association.\u003c/li\u003e\n \u003cli\u003eWolstenholme, A. J., Fairweather, I., Prichard, R., von Samson-Himmelstjerna, G., \u0026amp; Sangster, N. C. (2004). Drug resistance in veterinary helminths. \u003cem\u003eTrends in Parasitology, 20\u003c/em\u003e(10), 469\u0026ndash;476. https://doi.org/10.1016/j.pt.2004.07.010\u003c/li\u003e\n \u003cli\u003eMatthews, J. B. (2014). Anthelmintic resistance in equine nematodes. \u003cem\u003eInternational Journal for Parasitology: Drugs and Drug Resistance, 4\u003c/em\u003e(3), 310\u0026ndash;315. https://doi.org/10.1016/j.ijpddr.2014.10.003\u003c/li\u003e\n \u003cli\u003ePeregrine, A. S., Molento, M. B., Kaplan, R. M., \u0026amp; Nielsen, M. K. (2014). Anthelmintic resistance in important parasites of horses: Does it really matter? \u003cem\u003eVeterinary Parasitology, 201\u003c/em\u003e(1\u0026ndash;2), 1\u0026ndash;8. https://doi.org/10.1016/j.vetpar.2014.01.004\u003c/li\u003e\n \u003cli\u003eScott, I., \u0026amp; Hodgkinson, J. E. (2015). An evidence-based approach to worm control. \u003cem\u003eEquine Veterinary Education\u003c/em\u003e.\u003c/li\u003e\n \u003cli\u003eTzelos, T., \u0026amp; Matthews, J. B. (2016). Anthelmintic resistance in equine helminths and mitigating its effects. \u003cem\u003eIn Practice, 38\u003c/em\u003e(10), 489\u0026ndash;499. https://doi.org/10.1136/inp.i5287\u003c/li\u003e\n \u003cli\u003eRaza, A., Qamar, A. G., Hayat, K., Ashraf, S., \u0026amp; Williams, A. R. (2019). Anthelmintic resistance and novel control options in equine gastrointestinal nematodes. \u003cem\u003eParasitology, 146\u003c/em\u003e, 425\u0026ndash;437. https://doi.org/10.1017/S0031182018001786\u003c/li\u003e\n \u003cli\u003eJames, C. E., Hudson, A. L., \u0026amp; Davey, M. W. (2009). Drug resistance mechanisms in helminths: Is it survival of the fittest? \u003cem\u003eTrends in Parasitology, 25\u003c/em\u003e, 328\u0026ndash;335.\u003c/li\u003e\n \u003cli\u003eKaplan, R. M., \u0026amp; Nielsen, M. K. (2010). An evidence-based approach to equine parasite control: It ain\u0026rsquo;t the 60s anymore. \u003cem\u003eEquine Veterinary Education, 22\u003c/em\u003e(6), 306\u0026ndash;316. https://doi.org/10.1111/j.2042-3292.2010.00084.x\u003c/li\u003e\n \u003cli\u003eAyele, G., Feseha, G., Bojia, E., \u0026amp; Joe, A. (2006). Prevalence of gastrointestinal parasites of donkeys in Dugda Bora District, Ethiopia. \u003cem\u003eLivestock Research for Rural Development, 18\u003c/em\u003e(11). http://www.cipav.org.co/lrrd/lrrd18/10/aye18136.htm\u003c/li\u003e\n \u003cli\u003eNuraddis, I., Tilahun, B., Benti, D., \u0026amp; Tadele, T. (2011). Survey of prevalence of helminth parasites of donkeys in and around Hawassa, Southern Ethiopia. \u003cem\u003eGlobal Veterinaria, 6\u003c/em\u003e(3), 223\u0026ndash;227.\u003c/li\u003e\n \u003cli\u003eTihitna, S., Basaznew, B., Mersha, C., \u0026amp; Achenef, M. (2012). Occurrence of lungworm infection in equines and their associated risk factors. \u003cem\u003eGlobal Veterinaria, 8\u003c/em\u003e(1), 35\u0026ndash;38.\u003c/li\u003e\n \u003cli\u003eYacob, H. T., \u0026amp; Ashenafi, H. (2013). Epidemiological study on gastrointestinal helminths of horses in Arsi Bale highlands of Oromia Region, Ethiopia. \u003cem\u003eEthiopian Veterinary Journal, 17\u003c/em\u003e(2), 51\u0026ndash;62.\u003c/li\u003e\n \u003cli\u003eTilahun, B., Nuraddis, I., Benti, D., \u0026amp; Tadele, T. (2014). Prevalence of helminth parasites of horses in and around Hawassa Town, Southern Ethiopia. \u003cem\u003eActa Parasitologica Globalis, 5\u003c/em\u003e(1), 7\u0026ndash;11.\u003c/li\u003e\n \u003cli\u003eAsmare, K., Gelaye, E., \u0026amp; Ayelet, G. (2005). Anthelmintic resistance test in gastrointestinal nematodes of small ruminants in southern Ethiopia. \u003cem\u003eBulletin of Animal Health and Production in Africa, 53\u003c/em\u003e, 89\u0026ndash;95.\u003c/li\u003e\n \u003cli\u003eMenkir, S. M., Sissay, M. M., Uggla, A., \u0026amp; Waller, P. J. (2006). Anthelmintic resistance of nematode parasites of small ruminants in eastern Ethiopia: Exploitation of refugia to restore anthelmintic efficacy. \u003cem\u003eVeterinary Parasitology, 135\u003c/em\u003e(3\u0026ndash;4), 337\u0026ndash;346.\u003c/li\u003e\n \u003cli\u003eSvendsen, E. D. (1997). \u003cem\u003eThe professional handbook of the donkey\u003c/em\u003e (3rd ed.). Whittet Books.\u003c/li\u003e\n \u003cli\u003eReed, M. S., Bayly, M. W., \u0026amp; Sellon, C. D. (2004). \u003cem\u003eEquine internal medicine\u003c/em\u003e. Elsevier Saunders. Reinemeyer, C. R., \u0026amp; Nielsen, M. K. (2014). Review of the biology and control of \u003cem\u003eOxyuris equi\u003c/em\u003e. \u003cem\u003eEquine Veterinary Education, 26\u003c/em\u003e, 584\u0026ndash;591.\u003c/li\u003e\n \u003cli\u003eThrusfield, M. (2005). \u003cem\u003eVeterinary epidemiology\u003c/em\u003e (3rd ed.). Blackwell Science Ltd.\u003c/li\u003e\n \u003cli\u003eArsham, H. (2002). Descriptive sampling data analysis: Statistical thinking for managerial decision making. http://home.ubalt.edu/ntsbarsh/Business-stat/opre504.htm\u003c/li\u003e\n \u003cli\u003eSaari, S., N\u0026auml;reaho, A., \u0026amp; Nikander, S. E. (2018).\u0026nbsp;\u003cem\u003eCanine parasites and parasitic diseases\u003c/em\u003e. Academic Press.\u003c/li\u003e\n \u003cli\u003eLester, H. E., \u0026amp; Matthews, J. B. (2014). Faecal worm egg count analysis for targeting anthelmintic treatment in horses: Points to consider. \u003cem\u003eEquine Veterinary Journal, 46\u003c/em\u003e, 139\u0026ndash;145.\u003c/li\u003e\n \u003cli\u003eColes, G. C., Bauer, C. F., \u0026amp; Borgsteede, H. M. (1992). World Association for the Advancement of Veterinary Parasitology (WAAVP) methods for the detection of anthelmintic resistance in nematodes of veterinary importance. \u003cem\u003eVeterinary Parasitology, 44\u003c/em\u003e(1\u0026ndash;2), 35\u0026ndash;44.\u003c/li\u003e\n \u003cli\u003eJ\u0026oslash;rgensen, H., \u0026amp; Brian, P. (1994). \u003cem\u003eThe epidemiology, diagnosis and control of helminth parasites of ruminants\u003c/em\u003e. International Laboratory for Research on Animal Diseases (ILRAD).\u003c/li\u003e\n \u003cli\u003eWood, I. B., Amaral, N. K., Bairden, K., Duncan, J. L., Kassai, T., Malone, J. B., \u0026hellip; Vercruysse, J. (1995). WAAVP guidelines for evaluating the efficacy of anthelmintics in ruminants (2nd ed.). \u003cem\u003eVeterinary Parasitology, 58\u003c/em\u003e(3), 181\u0026ndash;213. https://doi.org/10.1016/0304-4017(95)00806-2\u003c/li\u003e\n \u003cli\u003eMurphy, L. M., Ehrlich, W. K., \u0026amp; Mayer, D. G. (2014). Anthelmintic resistance in ovine gastrointestinal nematodes in inland southern Queensland. \u003cem\u003eAustralian Veterinary Journal, 92\u003c/em\u003e(11), 415\u0026ndash;420. https://doi.org/10.1111/avj.12250\u003c/li\u003e\n \u003cli\u003eMinistry of Agriculture Fisheries and Food (MAFF). (1984). \u003cem\u003eManual of veterinary investigation laboratory techniques\u003c/em\u003e (Vol. 390).\u003c/li\u003e\n \u003cli\u003eBevilaqua, C. M. L., Rodrigues, M. D. L., \u0026amp; Concordet, D. (1993). Identification of infective larvae of some common nematode strongylids of horses. \u003cem\u003eRevue de M\u0026eacute;decine V\u0026eacute;t\u0026eacute;rinaire, 144\u003c/em\u003e(12), 989\u0026ndash;995.\u003c/li\u003e\n \u003cli\u003eLichtenfels, J. R., Kharchenko, V. A., \u0026amp; Dvojnos, G. M. (2008). Illustrated identification keys to strongylid parasites of horses, zebras, and asses. \u003cem\u003eVeterinary Parasitology, 156\u003c/em\u003e, 4\u0026ndash;161.\u003c/li\u003e\n \u003cli\u003eSangster, N. C. (1999). Pharmacology of anthelmintic resistance in cyathostomes. \u003cem\u003eVeterinary Parasitology, 85\u003c/em\u003e, 189\u0026ndash;201.\u003c/li\u003e\n \u003cli\u003eNielsen, M. K. (2016). Equine tapeworm infection: Disease, diagnosis, and control. \u003cem\u003eEquine Veterinary Education, 28\u003c/em\u003e, 388\u0026ndash;395.\u003c/li\u003e\n \u003cli\u003eLyons, E. T., Tolliver, S. C., Ionita, M., Lewellen, A., \u0026amp; Collins, S. S. (2008). Field studies indicating reduced activity of ivermectin on small strongyles. \u003cem\u003eParasitology Research, 103\u003c/em\u003e(1), 209\u0026ndash;215.\u003c/li\u003e\n \u003cli\u003eLeathwick, D. M., \u0026amp; Hosking, B. C. (2009). Managing anthelmintic resistance: Modeling strategic use of a new anthelmintic class. \u003cem\u003eNew Zealand Veterinary Journal, 57\u003c/em\u003e, 203\u0026ndash;207.\u003c/li\u003e\n \u003cli\u003eNielsen, M. K., Reist, M., Kaplan, R. M., Pfister, K., van Doorn, D. C. K., \u0026amp; Becher, A. (2013). Equine parasite control under prescription-only conditions in Denmark. \u003cem\u003eVeterinary Parasitology\u003c/em\u003e. https://doi.org/10.1016/j.vetpar.2013.10.016\u003c/li\u003e\n \u003cli\u003eBoersema, J. H., Eysker, M., Maas, J., \u0026amp; van der Aar, W. M. (1996). Comparison of the reappearance of strongyle eggs in foals, yearlings, and adults after treatment with ivermectin or pyrantel. \u003cem\u003eVeterinary Quarterly, 18\u003c/em\u003e, 7\u0026ndash;9.\u003c/li\u003e\n \u003cli\u003eIBM Corp. (2011). \u003cem\u003eIBM SPSS Statistics for Windows\u003c/em\u003e (Version 20.0). IBM Corp.\u003c/li\u003e\n \u003cli\u003eLind, E. O., Uggla, A. E., Waller, P. J., Morrison, D. A., \u0026amp; H\u0026ouml;glund, J. (2007). Parasite control practices on Swedish horse farms. \u003cem\u003eActa Veterinaria Scandinavica, 49\u003c/em\u003e(25).\u003c/li\u003e\n \u003cli\u003eHinney, B., Wirtherle, N. C., Kyule, M., Miethe, N., Zessin, K. H., \u0026amp; Clausen, P. H. (2011). Questionnaire survey on helminth control on horse farms in Brandenburg, Germany. \u003cem\u003eParasitology Research, 109\u003c/em\u003e(6), 1625\u0026ndash;1635.\u003c/li\u003e\n \u003cli\u003eNielsen, M. K., Reist, M., Kaplan, R. M., Pfister, K., van Doorn, D. C., \u0026amp; Becher, A. (2014). Equine parasite control under prescription-only conditions in Denmark. \u003cem\u003eVeterinary Parasitology, 204\u003c/em\u003e(1\u0026ndash;2), 64\u0026ndash;72.\u003c/li\u003e\n \u003cli\u003eSeyoum, Z., Zedwu, A., Dagnachew, S., \u0026amp; Bogale, B. (2017). Anthelmintic resistance of strongyle nematodes to ivermectin and fenbendazole in cart horses of Gondar. \u003cem\u003eBioMed Research International, 2017\u003c/em\u003e, 63\u0026ndash;96.\u003c/li\u003e\n \u003cli\u003eNielsen, M. K., Haaning, N., \u0026amp; Olsen, S. N. (2006). Strongyle egg shedding consistency in horses under selective therapy. \u003cem\u003eVeterinary Parasitology, 135\u003c/em\u003e(3\u0026ndash;4), 333\u0026ndash;335.\u003c/li\u003e\n \u003cli\u003eNielsen, M. K., Reist, M., Kaplan, R. M., Pfister, K., van Doorn, D. C. K., \u0026amp; Becher, A. (2013). Equine parasite control in Denmark. \u003cem\u003eVeterinary Parasitology\u003c/em\u003e. https://doi.org/10.1016/j.vetpar.2013.10.016\u003c/li\u003e\n \u003cli\u003eElghryani, N., Duggan, V., Relf, V., \u0026amp; de Waal, T. (2019). Questionnaire survey on helminth control practices in horse farms in Ireland. \u003cem\u003eParasitology\u003c/em\u003e, 1\u0026ndash;10. https://doi.org/10.1017/S0031182019000271\u003c/li\u003e\n \u003cli\u003evon Samson-Himmelstjerna, G., Fritzen, B., \u0026amp; Demeler, J. (2007). Reduced egg reappearance periods \u0026amp; \u003cem\u003eParascaris equorum\u003c/em\u003e drug failure. \u003cem\u003eVeterinary Parasitology, 144\u003c/em\u003e(1\u0026ndash;2), 74\u0026ndash;80.\u003c/li\u003e\n \u003cli\u003ePapadopoulos, E., Hamhougias, K., Himonas, C., \u0026amp; Dorchies, P. H. (2000). Strongyle anthelmintic resistance in horses and cattle in Greece. \u003cem\u003eRevue de M\u0026eacute;decine V\u0026eacute;t\u0026eacute;rinaire, 151\u003c/em\u003e(12), 1139\u0026ndash;1142.\u003c/li\u003e\n \u003cli\u003eFeseha, H., Mesfin, M., \u0026amp; Friat, K. (2020). Anthelmintic efficacy of ivermectin and fenbendazole on working donkeys in Hosaena, Ethiopia. \u003cem\u003eVeterinary Medicine International, 2020\u003c/em\u003e, Article 4868797.\u003c/li\u003e\n \u003cli\u003eTraversa, D., von Samson-Himmelstjerna, G., \u0026amp; Demeler, J. (2009). Anthelmintic resistance in cyathostomins from horse yards in Europe. \u003cem\u003eParasites \u0026amp; Vectors, 2\u003c/em\u003e(2).\u003c/li\u003e\n \u003cli\u003eCernea, M., Cristina, R. T., Tefanut, L. C., de Carvalho, L. M. M., Taulescu, M. A., \u0026amp; Cozma, V. (2015). Screening for anthelmintic resistance in equid strongyles in Romania. \u003cem\u003eFolia Parasitologica, 62\u003c/em\u003e(1), 1\u0026ndash;7.\u003c/li\u003e\n \u003cli\u003eMolena, R. A., Peachey, L. E., Cesare, A., Traversa, D., \u0026amp; Cantacessi, C. (2018). Cyathostomine egg reappearance period after ivermectin in UK Thoroughbreds. \u003cem\u003eParasites \u0026amp; Vectors\u003c/em\u003e, 3\u0026ndash;8.\u003c/li\u003e\n \u003cli\u003eAbebe, B. G. (2015). \u003cem\u003eImpact assessment of strategic mass deworming of donkeys in central Oromia, Ethiopia\u003c/em\u003e. Addis Ababa University.\u003c/li\u003e\n \u003cli\u003eFischer, J., Hinney, B., Zessin, K. H., von Samson-Himmelstjerna, G., \u0026amp; Clausen, P. H. (2015). \u003cem\u003eEfficacy of selected anthelmintic drugs against cyathostomins in horses\u003c/em\u003e. ISBN 978-3-86387-618-0.\u003c/li\u003e\n \u003cli\u003eLyons, E., Tolliver, S., Collins, S., Ionita, M., Kuzmina, T., \u0026amp; Rossano, M. (2011). Reduced activity of ivermectin and moxidectin against small strongyles. \u003cem\u003eParasitology Research, 108\u003c/em\u003e, 355\u0026ndash;360.\u003c/li\u003e\n \u003cli\u003eRelf, V. E., Lester, H. E., Morgan, E. R., Hodgkinson, J. E., \u0026amp; Matthews, J. B. (2014). Anthelmintic efficacy on UK Thoroughbred stud farms. \u003cem\u003eInternational Journal for Parasitology, 44\u003c/em\u003e, 507\u0026ndash;514.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Mekdela Amba University","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Anthelmintic resistance, ERP, FECRT, Gastrointestinal nematodes, Horses, Tulu-Awlia","lastPublishedDoi":"10.21203/rs.3.rs-8864548/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8864548/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eGastrointestinal nematode (GIN) infections are major constraints to horse productivity, with effective control relying largely on routine use of anthelmintic drugs. However, the emergence of anthelmintic resistance threatens the long term sustainability of this strategy. Therefore, a field-based experiment was conducted from November 2020 to May 2021 in and around Tullu-Awliya town of South Wollo Zone to evaluate the efficacy of commonly used anthelmintics against GINs in naturally infected horses and to assess the control practices of horse owners. Fecal samples from 520 randomly selected horses were examined using flotation and modified McMaster techniques. Horses with fecal egg counts (EPG\u0026thinsp;\u0026ge;\u0026thinsp;150) were assigned into six groups of ten, representing cart and pack horses. Four groups received either Ivermectin or Fenbendazole, while two served as untreated controls. Fecal samples collected on day 0 and day 14 were subjected to fecal egg count reduction tests (FECRT) to determine anthelmintic efficacy. Copro culture and modified Baermann techniques were used to identify L3 larvae associated with suspected resistance. Egg reappearance period (ERP) was also conducted to detect anthelmintic efficacy in packing horses. Additionally, a questionnaire survey involving 201 horse owners documented helminth control and anthelmintic use practices. The FECRT results showed mean fecal egg count reductions of 94.01% for Ivermectin and 99.6% for Fenbendazole, with significant differences between treated and control groups. Ivermectin exhibited suspected resistance, and Strongylus vulgaris, Strongylus equinus, and Cyathostomum spp. were identified post treatment of Ivermectin. Moreover, ERP results suggested no anthelmintic resistance in pack horses. The survey indicated that Ivermectin 62.3%, followed by Fenbendazole 31.8%, were the most widely used anthelmintics. These findings highlight the need for improved awareness of rational anthelmintic use and adoption of resistance‑management strategies, alongside further studies on factors contributing to reduced drug efficacy.\u003c/p\u003e","manuscriptTitle":"Field Efficacy Evaluation of Commonly Used Anthelmintics Against Gastrointestinal Nematodes on Naturally Infected Horses in and around Tulu Awuliya Town, North East Ethiopia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-16 04:20:18","doi":"10.21203/rs.3.rs-8864548/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"fcd3861b-2e90-424f-8589-2097bee2014b","owner":[],"postedDate":"February 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":62972478,"name":"Animal Science"}],"tags":[],"updatedAt":"2026-02-16T04:20:18+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-16 04:20:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8864548","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8864548","identity":"rs-8864548","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}