Acute hepatic necrosis associated with Trema micranthum poisoning in cattle in Brazil.

Trema micranthum (L.) Blume (Jamaican nettletree) is a hepatotoxic tree that is widely distributed throughout the Americas and has been associated with poisoning in several domestic animal species. To our knowledge, spontaneous intoxication in cattle has not been reported previously. Here, we describe 2 spontaneous outbreaks of T. micranthum poisoning in Nelore cows in the state of Mato Grosso, Brazil. Affected cattle developed apathy, ataxia, and recumbency, followed by death within hours. Autopsy revealed jaundice and enlarged livers with a diffuse mottled red-and-white appearance. Histologically, severe centrilobular-to-massive hepatocellular coagulative necrosis was observed. Epidemiologic investigation identified recent access to paddocks containing vigorously sprouting T. micranthum following deforestation or tree fall, with clear evidence of grazing. The combination of pathology findings and field investigation established the diagnosis of acute toxic hepatopathy caused by T. micranthum.