HEMATOLOGICAL, HEMOSTATIC AND BIOCHEMICAL DISTURBANCES INDUCED BY Crotalus durissus terrificus ENVENOMATION IN DOGS

Sousa-e-Silva, M.C.C.(1), Tomy, S.C.(1), Tavares, F.L.(1), Navajas, L.C. (2), Larsson, M.H.A.(2), Sano-Martins, I.S.(1)

(1)laboratório de Fisiopatologia, Instituto Butantan, (2)Clínica Médica, Faculdade de Medicina Veterinária e Zootecnica da USP, SP, Brazil.

The aim of this study was to investigate the hematological, hemostatic and biochemical alterations induced by Crotalus durissus terrificus venom (VCdt) in dogs. Three groups of animals were used: an experimental group (E) that was injected intramuscularly with VCdt (1 mg/kg) and 2 hours later was treated with Crotalus antivenom (i.v.), a control group(C) that was injected with saline (i.m.), and a control group (AV) injected with saline (i.m.) and 2 hours later was treated with Crotalus antivenom. Blood samples for biochemical, hematological and hemostatic parameters were collected at 24 hours before, 2 h after venom or saline administration, and 24 and 48 hours following serumtherapy. The levels of alkaline phosphatase and alanine aminotransferase were increased in E and AV groups at 24 and 48 hours after serumtherapy. The high levels of the enzymes creatinekinase, aspartate aminotransferase and myoglobin demonstrate that the animals developed rhabdomyolysis. These alterations were not normalized 48 h after the administration of antivenom. No alterations were observed for other analyzed biochemical parameters. No evidence of erythron disturbances was observed. However, 2 hours after envenomation, a persistent neutrophilic leukocytosis was observed, which lasted even after serumtherapy. The animals of E and AV groups presented eosinopenia at 24 hours after serumtherapy. After 2 hours of envenomation the animals presented altered coagulation time, prothrombin time and activated partial thromboplastin time, fibrinogen and alfa₂-antiplasmin consumption, increased levels of fibrinogen/fibrin degradation products (FDP) and platelet hypoaggregation. The increased levels of FDP and the decreased alfa₂-antiplasmin levels indicate secondary activation of the fibrinolytic system. Our data suggest that the biochemical and hemostatic disturbances induced by Cdt venom in dogs are related to its myotoxic and thrombin-like activities.

CORRESPONDENCE TO:

Maria Cristina Cirillo de Sousa e Silva, Avenida dos eucaliptos 217, Apto. 133, SP, CEP: 04517-050, Brasil, Email: mccss@yahoo.com