Clinicopathologic abnormalities associated with snake envenomation in domestic animals

Abstract

Envenomation of domestic animals by snakes occurs frequently in certain geographic areas.However, reports describing clinical signs, clinicopathologic abnormalities, therapeutic approaches, and outcomes are sparse. This review summarizes various snake families, venom types associated with harmful snakes, and the significant hematologic, hemostatic, and biochemical abnormalities associated with envenomation. Hematologic abnormalities include RBC membrane abnormalities, hemolysis, hemoconcentration, leukogram changes, and platelet abnormalities, specifically thrombocytopenia.Coagulopathies associated with snake envenomation are well described in human medicine, and many studies have demonstrated properties of venoms that lead to both procoagulation and anticoagulation.As expected, similar abnormalities have been described in domestic animals. Biochemical abnormalities are associated with the effects of venom on tissues such as liver, skeletal and cardiac 2 muscle, vascular endothelium, and kidney as well as effects on protein components and cholesterol.This comprehensive review of clinicopathologic abnormalities associated with envenomation and their relationship to characterized venom constituents should be useful both in the diagnosis and management of envenomation and serve as a foundation for future research in this field.

Red-bellied black snake (Pseudechis porphyriacus) envenomation in the dog: Diagnosis and treatment of nine cases

“…However in these tiger snake cases the effect was delayed several days rather than hours. In vitro studies of other venoms have also shown that increasing doses of venom increase the degree of red cell membrane changes and spherocyte formation, particularly with viper venoms (Goddard et al, 2011;Walton et al, 1997). However, in this series, as with an earlier human study (Churchman et al, 2010), there was no clear correlation seen between the observed circulating venom levels and the severity of clinical effects such as the presence or absence of haemolysis.…”

Venomous and Poisonous Australian Animals of Veterinary Importance: A Rich Source of Novel Therapeutics

“…Hematological effects consistent with significant derangement of coagulation included marked thrombocytopenia, depletion of serum fibrinogen, prolonged prothrombin, and activated partial thromboplastin time [24]. The group C prothrombin activators in brown snake venom closely resemble mammalian prothrombinase (Xa:Va) which converts prothrombin into thrombin; thus the venom activates coagulation resulting in a consumptive coagulopathy termed venominduced consumptive coagulopathy [26]. …”

Evaluation of snake envenomation-induced renal dysfunction in dogs using early urinary biomarkers of nephrotoxicity

“…The most commonly observed clinical manifestations of renal abnormalities after snake envenomation in humans and dogs are acute kidney injury (AKI), proteinuria and hematuria (Sitprija, 2006;Kanjanabuch and Sitprija, 2008;Goddard et al, 2011) The majority of studies and reports of snake envenomation in dogs have focused on routine serum analyses and only to some extent on urinalysis (Heller et al, 2007;Lervik et al, 2010;Gilliam and Brunker, 2011;Sutton et al, 2011). Nevertheless, these parameters are nonspecific and insensitive as they are only altered at the point when about 50 -75% of renal function is already lost (Finco, 1997).…”

“…As a highly vascularised organ and also as a major elimination route of the snake venom, human and animal kidneys are very susceptible to nephrotoxic effects of envenomation (Sitprija, 2006;Kanjanabuch and Sitprija, 2008;Mello et al, 2010). Kidney injury after envenomation in humans, dogs and rats was reported to be caused either by a direct action of venom or an indirect action through inflammatory mediators, and nephrotoxic effects of myo-and haemoglobin, hypovolemia, disseminated intravascular coagulopathy (DIC) and renal ischemia (Sitprija, 2006;Mello et al, 2010;Goddard et al, 2011;Jacoby-Alner et al, 2011). Renal pathology inflicted by snake venom involves all renal structures, i.e.…”