Wedelia glauca poisoning in cattle in Uruguay

Abstract

An outbreak of spontaneous intoxication by Wedelia glauca in bovine, with sudden deaths in cows in the county of Soriano is reported. Of 130 pregnant cows 23 animals were affected (morbidity 17,6%, mortality 17,6% and lethality 100%). The most important macroscopic findings were swollen liver, congestion and mottled appereance with red areas intercalated with yellow areas. Gallbladder had oedema and enlarged wall. Small and large intestine with congestion or hemorrhagic areas. Histopathological examinations of the liver showed severe periacinar hemorrhagic necrosis and periportal fatty infiltration, whereas kidney had tubular degeneration and necrosis. Intestine had severe enteritis with mononuclear cell infiltration. Aerial parts of dried Wedelia glauca were administered at dose of 2 and 5 gr of DM/kg of body weight to two calves, being toxic at dose of 5 gr of DM/kg of bw. Macroscopic and microscopic lesions of this animal were similar to those observed in the cows affected spontaneously, confirming the toxicity of this plant. W. glauca is considered plague in Argentina, being the main toxic plant of Pampa Húmeda region and causes largest number of deaths in cattle. For this reason, it is important to identificate and control the plant in Uruguay.