Death camas poisoning in sheep: a case report

Approximately 250 sheep were poisoned and died from ingesting death camas (Zygadenus paniculatus) within a 2-day period on a foothill range in southeastern Idaho. Sixty to 70% of the poisoned sheep were 80-90 lb lambs and the rest were mature ewes. Poisonings were confirmed by field investigation, microhistological analysis of plant fragments from rumen contents of dead sheep, clinical signs, gross and microscopic analysis of tissues, and by experimentally feeding death camas collected on the poisoning site to 3 ewes at the Poisonous Plant Research Laboratory at Logan, UT. Clinical signs and gross and microscopic analysis of tissues were similar in ewes from the field investigation to those in ewes experimentally fed death camas. Ataxia, muscular weakness, trembling, incoordination, discharge of frothy saliva from the mouth and nose, vomition, dyspnea, collapse and death were the most common clinical signs. Gross changes included severe pulmonary congestion and subcutaneous hemorrhage. Microscopic lesions were those of severe pulmonary congestion.