RESUMO
Bothrops alternatus venom was intramuscularly inoculated (3mg/kg) into 12 dogs, 30 to 65 days old. Spontaneou bleeding commenced twenty minutes later. Blood samples obtained 3 and 20 minutes after venom inoculation presented spontaneuous clotting formation. Plasmatic fibrinogen decreased within 3 minutes. Partial thromboplastin time (PTT) and one-stage prothrombin time (PT) were found. Plasma did not coagulate 40 minutes after inoculation. Platelet counts did not vary but their function was altered. Histopathology pointed out severe muscular necrosis and massive hemorrhage in the inoculation area. Regional ganglia showed intense hemorrhage. The 45 and 65-day-old animals showed alveolar thickening of the septum and generalized congestion, but the 30-day-old animals showed thrombosis of small arteries and arterioles. Renal lesions were different with the age. Cortical tubular necrosis was present in puppies, and intense cortical tubular hydropic degeneration was present in adult dogs. Thymus hemorrhage and necrosis were present.