Crotalaria spectabilis Roth. (Fabaceae, Papilionoideae) seed poisoning in cattle and use of liver biopsy to diagnose subclinical disease

Intoxicação por sementes de Crotalaria spectabilis Roth. (Fabaceae, Papilionoideae) em bovinos e a utilização de biópsia hepática para diagnosticar doença subclínica

ABSTRACT:

Crotalaria spectabilis seed poisoning has been reported in cattle on rural properties in Diamantino and Campo Verde municipalities in Mato Grosso, Brazil. The disease appeared 75 to 120 days after the animals were fed a diet contaminated with C. spectabilis seeds. Clinically, the animals showed a lack of appetite, progressive weight loss, apathy, photosensitivity, lateral recumbency, and death. Some animals developed neurological manifestations as a consequence of hepatic encephalopathy. In total, 37 cattle died, and six cattle were necropsied. The main macroscopic changes consisted of ascites and a firm and decreased liver with an irregular surface and multifocal pale yellowish discoloration. Microscopically, hepatocyte loss with fibrosis, megalocytosis and bile duct proliferation was observed. Animals with severe hepatic damage also had status spongiosus in the central nervous system. Furthermore, a hepatic biopsy of 15 cows who consumed contaminated grains but did not develop clinical disease revealed histologic liver changes similar to necropsied animals.

INDEX TERMS:
Crotalaria spectabilis ; hepatic fibrosis; pyrrolizidine alkaloids; monocrotaline; cattle