From 2007 to 2009 a nephrotoxic disease of subacute course and high mortality in goats occurred on a farm in the county of Itaguaí, Rio de Janeiro. Metternichia princeps, a plant of the Solanaceae family, was suspected to be the cause. Through experiments in goats the clinical-pathological picture of poisoning by the plant and the lethal dose were established. For the experiments 12 young and adult goats of different races, both sexes and with weights above 15 kg were used. The goats that received 30g/kg in 5 days, 15g/kg in 3 days, single doses of 10g/kg and 5g/kg, all died. Of two goats that received single doses of 2.5g/kg, one died but the other did not show any clinical sign; a goat that received the single dose of 1.25g/kg also did not show any symptom of poisoning. First clinical signs were observed from 7 hours to 46h45min after the plant intake. The clinical course varied from 3h6min to 126h40min. First clinical signs were loss of appetite, adipsia, apathy and reluctance to move. After the animals entered in sternal decubitus and when they were placed in standing position, they kept their front limbs flexed, supported only by the posterior limbs on the floor until evolving into flexion of all four limbs followed by lateral decubitus. Postmortem examination revealed edema of the perirenal adipose tissue, pale kidneys which on the cut-surface showed whitish stripes from the cortex to the medullar area. At histopathology, severe coagulative necrosis of epithelial cells of the kidney tubules was seen. Compared with the natural cases, the goats experimentally poisoned by M. princeps, presented a similar clinic-pathological picture. By these experiments it could be proved that Metternichia princeps is the toxic plant that causes a nephrotoxic disease in goats in the Rio de Janeiro area; the minor lethal dose was 2,5g/kg in the experiments.
Poisonous plants; Metternichia princeps; Solanaceae; pathology; ruminants