Nierembergia hippomanica poisoning in cattle and sheep

Abstract

Eight outbreaks of intoxication by Nierembergia hippomanica were diagnosed in cattle in Uruguay between January and July, from 1989 to 1994. Morbidity was between 10% and 80%, and deaths did not occur. All outbreaks ocurred in cultivated pastures or wheat or barley stuble fields. Invasion of pastures by the plant was apparentely due to the utilization of seeds contaminated by seeds of N. hippomanica. Clinical signs were characterized by diarrhea, restlessness, abdominal pain and periodic motion of the head and limbs. Milking cows had a decreased milk production. The green plant was dosed experimentally to cattle and sheep at 10 to 50 g per Kg of body weight. The lower toxic dose was from 15 to 5Og/Kg. No differences were observed in the toxicity of plant samples collected in winter or spring. Clinical signs were similar to those observed in field cases. All animals recovered in 1 to 8 days, except one calf thilt died after the ingestion of 50 g/Kg. The main lesions were focal hemorrhages in the large intestine and enteritis in the small intestine. The dried plant was not toxic to cattle and sheep. One steer that received 10 daily doses of 5g/Kg showed clinical signs after the last dose demonstrating an acumulative effect in the plant. One sheep that received 20 gr/Kg of the plant colected in winter presented inappetency, diarrhea, abdominal pain and restlessness, and that one which ingested the same dose of plant but colected in spring, showed discreet restleesneed and sialorrhea.