A Prospective Clinico-Epidemiological Evaluation and Management of Hump Nosed Pit Vipers (Hypnale Hypnale) Bite Envenoming in Dogs

Human envenoming from the bite of the abundant hump nosed pit viper ( Hypnale hypnale ) (HNPV) is a frequent occurrence with victims experiencing unpleasant and sometimes life-threatening consequences. Regrettably, our therapeutic armamentarium remains limited. Further, clinico-pathology, treatment and management measures in HNPV envenomed dogs are under recognized. Prospective investigations were performed to assess the clilinico-pathology and management options for HNPV envenomed dogs brought to the University of Peradeniya’s Veterinary Teaching Hospital from January, 2012 to March 2018. We recorded the local and systemic clinical manifestations, hematological and urinary abnormalities of 78 dogs in which HNPV bite had been witnessed by the owner. Mild swelling, extensive swelling, hemorrhagic blistering and hemorrhagic bullae at the site of bite were observed in 59%, 31%, 6% and 4% of the dogs, respectively. Some dogs were subjected to surgical excision of necrotized tissue including limb amputation. We observed the following systemic clinical effects in envenomed dogs: neurotoxicity (13%), acute kidney injuries (AKI) (14%) and coagulopathy (16%). All dogs showed leukocytosis with mean white blood cell count of 25.25×10 3 /µL. Mild anemia and thrombocytopenia were detected in 29% of the dogs. There was a significant correlation between extent of local tissue injuries with length of hospitalization (LH). The mean time of coagulopathy observed was 21.3 hours (IQR: 8-48 hours). In coagulopathic dogs, there was a strong correlation between LH and extent of local tissue injury ( r s = 0.7751, P  < 0.0001); LH and clotting time ( rs = 1.0, P  < 0.0001); PT and aPTT ( r s = 0.4712, P  < 0.001). LH was significantly correlated with the development of AKI ( p =0.0013). Lack of specific AVS for HNPV envenoming provided an opportunity to study the remaining treatment options. Therefore, the study allowed the identification of local and systemic effects, hematological abnormalities, possible auxiliary treatments and drawbacks of management measures for envenomed dogs.