It is important to consider plant toxicities when diagnosing death losses. Many plants are toxic or potentially toxic to sheep. Some plants accumulate toxins during specific times of their growing cycle or after periods of environmental stress. The incidence of plant poisoning in livestock tends to increase when normal forages are scarce, causing animals to eat plants that they would not normally eat.
The signs of plant poisoning are as varied as the plants themselves and may mimic other diseases. Many poisonous plants cause sudden death. Some plants cause photosensitization (a severe skin reaction). Other poisonous plants affect the nervous system. Some plant poisonings can be treated, if signs are recognized early. For many plant toxins, there are no treatments.