Epidemiology of snakebite in dogs in Sri Lanka

Abstract

Dogs (Canis familiaris) have several behavioral characteristics that may contribute to snakebites. Dogs generally are inquisitive, lack ophidiophobia (fear of snakes), and may attack a snake in defense of self or a human companion. This is a descriptive cross-sectional study of 115 dogs presented to the Veterinary Teaching Hospital during a 36 month period with bites caused by three venomous snakes namely; Russell's viper, (Daboia russelii: n ¼ 65) cobra (Naja naja: n ¼ 36) and hump nosed viper (Genus Hypnale: n ¼ 14). Adult dogs (2-8 years: 58%) and medium sized breed dogs (60%) were the frequent victims of snakebites and the least number of envenomation were reported from small sized breeds (5%). Despite treatments, the highest number of deaths resulted with D. russelii (n ¼ 8, 7%) bites followed by N. naja (n ¼ 4, 3.5%). Fang marks were multiple (50% of dogs), single (42%), or unidentifiable (8%). Most bites of Russell's viper and hump nosed viper were nocturnal, clustered around dusk and dawn while all cobra bites were reported only at day time.

Clinico-epidemiology and management of hump-nosed pit viper (Hypnale spp.) bites in dogs

“…Consistent with studies of snakebite incidence from other venomous snakes this study observed a higher proportion of males suffered HNPV bites. It is hypothesised this reflects the more prominent territorial behaviour of male dogs 8 , 22 , 23 . This observation parallels the incidence of snakebite in human males in farming communities due to social norms governing occupational roles 4 , 25 .…”

“…H. hypnale is most commonly found under stones, logs and leaf litter in and around human settlements. Therefore, the pattern of behaviour of both dog and HNPV increases the possibility of envenoming in dogs at dusk and dawn 8 . By contrast the majority of HNPV bites in human are reported in day time in their home gardens 2 .…”

“…Although human fatalities from HNPV bite are infrequent they occur across a widely dispersed area in Sri Lanka and South-Western India, a high incidence being reported 1 , 3 – 7 . However, HNPV envenoming has a low comparative incidence in dogs 8 . H. hypnale is one of the first snakes for which the pathophysiology of envenoming was scientifically studied.…”

Clinico-epidemiology and management of Russell’s viper (Daboia russelii) envenoming in dogs in Sri Lanka

“…Predictable local and systemic effects due to envenoming and their progression were documented according to studies conducted by Refs. [2,19,3], on envenoming. Expected local clinical manifestations of envenoming due to Russell’s viper bites included inflammation (swelling, pyrexia, and erythema), bruising, blistering, and local necrosis at the site detected by fang marks, pain, haemorrhages from inter-digital spaces and gingival regions, lymphadenopathy, and infected wounds at the site of the bite.…”

“…It is the deadliest venomous viper in Sri Lanka [1,2]. The high morbidity and mortality due to snakebites in dogs in Sri Lanka result from Russell's viper ( Daboia russelii ), cobra ( Naja naja ), and hump nosed viper (Genus Hypnale ) [3]. The proteome profile of Sri Lankan Russell’s vipers is identical, where composition of the venom is dominated by the neurotoxic basic phospholipases A2 (>30% of total protein abundance) and several hemotoxic or coagulopathic protein families (approximately 50% in total) and is correlated with the functional and toxinological characterizations of the venom, and reflects the pathophysiological effects of envenoming [4].…”