Poisonig of cattle and sheep on Brachiaria decumbens pastures contaminated with Pithomyces chatarum

Abstract

Herd histories and clinical observations of outbreaks of poisoning with symptoms of photosensitization, which occurred in cattle and sheep on Brachiaria decumbens Stapf. pastures in the State of Mato Grosso, are presented. Post-mortem examination of five bovines and Iwo sheep revealed liver jaundice in several as the most important lesion. Histopathological changes were vacuolization and slight necrobiosis of liver cells, bilary stasis, pericholangitis with bileduct proliferation and slight fibrosis. Spores of the fungus Pithomyces chartarum (Berk. & Curt.) M.B. Ellis were detected in B. decumbens grass samples from all farms where outbreaks occurred. The findings strongly suggest that the disease is caused by P. chartarum.