Abstract
The artifactual development of endothelial necrosis, pulmonary congestion, and oedema that has been reported in dogs, cats, and monkeys when the animals were killed with 1-1·5 ml/kg body weight of the euthanasia agent T-61 was reproduced in adult ewes of the merino breed. This species also exhibited a marked pulmonary congestion with intra-alveolar haemorrhages, septal oedema, and a diffuse cellular damage of the alveolar septa when the recommended dose of 0·3 ml/kg body weight was administered after forcing blood flow through one lung by clamping the contralateral hilum. The red coloration of the damaged lung areas may be due to haemolysis, another aspect of T-61 induced cell damage in this species. The degree of haemolysis increases with increasing blood concentration of the agent and approximates complete haemolysis at a T-61 blood concentration of 5%. The blood concentration dependent degree of haemolysis in sheep suggests a similar relationship between blood concentration of the agent and degree of pulmonary tissue damage.