With few exceptions, grazing animals will not eat poisonous plants unless forced to do so by some unusual or artificial condition. Lack of good forage, feeding a deficient diet, and feeding clippings from the yard, garden, or houseplants are situations to avoid. Many causes of poisoning cannot be related to a particular situation. Sometimes animals accidentally eat a poisonous plant while grazing or eating hay into which these plants have been mixed. There are a variety of chemical substances, like glycosides, alkaloids, oxalate and resins, found in toxic plants.
Numerous factors influence the action of the poisonous substances and severity of the poisoning.
Preventing the consumption of toxic plants is first and foremost, however, knowledge of proper treatment is just as important.