Spontaneous poisoning by Brachiaria hybrid cv. mulato I in goats and sheep and experimental poisoning of Brachiaria hybrid cv. mulato II in sheep

Abstract

Described is the epidemiology, clinical signs and lesions of a disease that leads to photosensitization and death in sheep and goats. Spontaneous disease occurred in the municipality of Abelardo Luz, SC. From a flock of 350 sheep and 278 goats grazing Brachiaria hybrid cv. mulato I, 27 animals got sick, which 17 died and 10 recovered after being removed from the pasture. The disease was characterized by tearing, hyperemia, swelling of face, ears and eyelid followed by crusting, serous nasal discharge, ulcers on the cornea and sclera, and conjunctiva slightly yellowish. Six sheep and eleven goats were necropsied on the farm. The macroscopic lesions were brownish liver, distended gallbladder and lumpy bile, brownish kidneys with red dots on surface. Through microscopy was observed mild to moderate lesions in liver mainly characterized by swelling and vacuolation of hepatocytes, megalocytosis, periportal fibrosis, biliary hyperplasia; small clusters of macrophages and infiltration of eosinophils, neutrophils and macrophages were present in the periportal area. Crystal negative images were detected within bile ducts. Kidney tubules were dilated ranging from mild to severe with glomerular tuff contraction and distension of Bowman space. Four sheep experimentally fed Brachiaria hybrid cv. mulato II ad libitum for 90 days showed no clinical changes.