Prussic acid is not normally present in plants; however, under certain conditions, several common plants can accumulate large quantities of cyanogenic glycosides which can convert to prussic acid. The risk of prussic acid poisoning in livestock is increased during periods of drought, and even more so after drought breaks when stressed, stunted plants begin to grow.

Prussic acid is a potent, rapidly acting poison, which enters the bloodstream of affected animals and is transported through the body. It then inhibits oxygen utilisation by the cells so that, in effect, the animal dies from asphyxia.

Prussic acid is also known as hydrocyanic acid (HCN). This Primefact includes information on the following:

• What is prussic acid poisoning?
• Sources of poison
• Plant factors
• Animal factors
• Signs of poisoning
• Diagnosis
• Treatment
• Prevention
• Testing feed samples.