Final answer:
Ergotism in animals is caused by the ergot toxin from the fungus Claviceps purpurea, leading to gangrenous or convulsive symptoms, such as gangrene or hallucinations, especially in cattle which may also suffer from loss of milk production.
Step-by-step explanation:
The symptoms associated with ergotism in animals are primarily the result of a mycotoxin known as ergot toxin, produced by the fungus Claviceps purpurea. Ergotism comes in two forms: gangrenous and convulsive. The gangrenous form leads to vasoconstriction which can cause improper blood flow to extremities, eventually leading to gangrene. The convulsive form, on the other hand, affects the central nervous system, causing symptoms such as mania and hallucinations. In animals like cattle, ergotism can lead to loss of milk production, convulsions, and gangrene.
Its occurrence in history as a devastating epidemic in humans underscores the significant impact this fungal infection can have. The importance of this mycotoxin extends to animal health, as exposure to contaminated grains can produce severe and sometimes life-threatening symptoms in livestock.