Plants causing sudden death in livestock

A number of plants are capable of producing intoxication of sufficient severity as to cause death within 12 hours of the onset of clinical signs. Those most rapid in their lethal effects are the cyanogenic plants and yew. Nitrate-accumulating plants likewise are capable of causing sudden death with only a brief appearance of signs. Most toxic plants, however, typically either require a longer time for the intoxication to develop and become lethal or sudden death is the exception rather than the rule following ingestion. In these cases, diagnosis of the problem may be facilitated by recognition of arrays of clinical signs that appear. Seven major groups of presenting signs can be distinguished: dyspnea and polypnea, hemorrhage, prominent excessive muscular activity, depression and/or weakness, diarrhea and weakness, excessive salivation and/or regurgitation and/or colic, and weakness and incoordination and/or tremors. Based on these and accompanying signs in surviving animals, many of the causes of sudden death can be differentiated. In addition, pathological changes visible on necropsy and identification of plant fragments in the rumen and stomach may be of diagnostic value.