Lantana camara poisoning in cattle and sheep in Uruguay

Abstract

In the influence area of Northwest Regional Laboratory of DILAVE «Miguel C. Rubino» were registered three outbreaks of intoxication by Lantana camara, between 1991 and 1994 in the counties of Paysandú and Río Negro. Two of them affected sheep (morbidity 34% and 90%; mortality 32,2% and 87% respectively) and the other one was in cattle (morbidity and mortality 100%). Affected categories were wethers and ewes, in bovine were cows. The outbreak in cattle was in April, while in ovine, both were in December. All cases occurred when the animals entered in parks or gardens of the farms with the presence of the plant. The main clinical signs in sheep were: photosensitization, weight loss, jaundice and photophobia. The principal macroscopic findings were jaundice, yellowish gelatinous subcutaneous edema, swollen liver with ocher or orange coloration and light brown kidney. Histopathological findings of liver showed severe vacuolation of hepatocytes, cholestasis and necrosis of the periportal region. Acute deaths with few clinical signs were observed in the outbreak occurred in cattle. The macroscopic appearance and histological lesions were similar to those of sheep. The green plant from two sources was administered experimentally to confirm the etiology, to two sheep at dose 20- 40 g/kg lw and one cattle at dose 25 g/kg lw, it was toxic to both species. Clinical signs and pathology were similar to those observed in field cases.