Prevalence of cervicitis in dairy cows and its effect on reproduction

The objective of this study was to determine whether cervicitis in dairy cows is an independent disease or occurs concomitantly with inflammation of the uterus, and to clarify possible effects of cervicitis on reproductive performance. Dairy cows (n = 416) from 33 dairy farms were examined by rectal palpation and vaginoscopy between 42 and 50 days postpartum. Inclusion criteria for this study were absence of abnormal vaginal discharge and abnormalities of the uterus (fluctuation) at rectal palpation. Cervicitis was diagnosed when the second cervical fold was swollen and prolapsed with (C2) or without (C1) reddening. Cytobrush samples from the uterus (n = 370) and the cervix (n = 402) were collected, and the percentage of neutrophils in the uterus (PMNU) and the cervix as indicators of inflammation (threshold: ≥5%) was determined. In addition, endometrial biopsies for histology were collected, 300 of which were suitable for evaluation. Cervicitis (C1/C2) was diagnosed in 253 of 416 (60.8%) of cows. Of these, the prolapsed cervical mucosa was hyperemic (C2) in 29.1% of cases. Of 370 available uterine cytology samples, 221 cows had a clinical cervicitis; however, 170 (76.9%) had PMNU less than 5%. Of 300 uterine histologic examinations, 82 (27.3%) did not reveal any abnormalities; the remaining cows either had uterine inflammation and/or degenerative uterine changes such as endometriosis and angiosclerosis. Furthermore, of 300 biopsied animals, 184 revealed a cervicitis (C1/C2); however, 30.4% of these animals had no histopathologic uterine findings. For further analysis, only animals either without histopathologic findings and normal uterine cytology or with solely endometritis (defined as PMNU ≥ 5% and/or positive histopathology of the uterine tissue) were evaluated (n = 157). Of these, 95 cows had cervicitis. Unexpectedly, 63 of 95 (66.3%) cows had cervicitis without endometritis. With regard to reproductive performance, days to first service were not affected by cervicitis. Number of days open in animals with cervicitis but without endometritis tended to be lower than in cows with cervicitis plus endometritis (P = 0.092). Also, number of days open relative to percentage of neutrophils greater than 5% was lower when the cervical compared to the uterine mucosa was affected (P < 0.05). Total conception and pregnancy rates of animals 200 days into lactation decreased significantly in cows with severe cervical inflammation (C2). In conclusion, the results of this study suggested that cervicitis occurs independent of endometritis, and a higher degree of cervicitis is associated with poorer reproductive performance.