Aspectos clínico-patológicos e laboratoriais do envenenamento crotálico experimental em equinos

Lopes C.T.A., Tokarnia C.H., Brito M.F. Sousa M.G.S., Oliveira C.M.C., Silva N.S., Lima D.H.S. & Barbosa J.D. 2012. [Clinical and pathological aspects of experimental crotalic envenoming in horses.] Aspectos clinico-patologicos e laboratoriais do envenenamento crotalico experimental em equinos. Pesquisa Veterinaria Brasileira 32(9):843-849. Central de Diagnostico Veterinario, Universidade Federal do Para, Rua Maximino Porpino da Silva 1000, Pirapora, Castanhal, PA 68743-080, Brazil. E-mail: cinthiatal@gmail.com The clinic-pathological picture and laboratory findings in horses experimentally inoculated with the venom of Caudisona durissa terrificus (Crotalus durissus terrificus, according to the former nomenclature) are described. The purpose of this study was to contribute to the understanding of this type of snake accident in horses. The lyophilized venom was diluted into 1ml of a 0.9% saline solution and was inoculated subcutaneously into five horses, at the doses of 0.12mg/kg (one horse), 0.066mg/kg (two horses) and 0.03mg/kg (two horses). The venom caused death of the horse that had received 0.12mg/kg, and of one horse of the two that had received the dose of 0.066mg/kg. The clinical course varied from 27h27min to 52h29min. The second horse inoculated with 0.066mg/kg recovered within 12 days after inoculation. The dose of 0.03mg/kg had a course of 6 to 10 days, but did not cause fatal envenomation. The clinical picture in the horses was characterized by swelling of the inoculation site (shoulder) that spread to the whole leg, by apathy and lowered head, locomotory alterations shown by dragging of the hoves on the ground, decubitus and difficulty to get up, reduction of auricular, palatal, upperlip and threat reflexes, and increase of heart and breathing frequency. The laboratory examination revealed leukocytosis and lymphocytosis in two horses. There was increase of the creatine-kinase (CK), lactic dehydrogenase (DHL) and urea, and reduction in the seric levels of calcium, phosphorus and magnesium. The activated partial tromboplastina time (TTPA) increased in the horses that died. Postmortem findings were edema of the subcutaneous tissue of the whole leg into which the venom was inoculated, suffusions in the epicard of left and right heart ventricles, and bladder with hemorrhagic areas in its mucosa. Histopatologic examination revealed the liver parenchyma with diffuse moderate vacuolation affecting predominantly the intermediate area of the hepatic lobe, and slight dilation of the sinusoides in some areas, and slight dilation of the kidney tubules mainly in the cortex.