Botulism is a rare but sometimes fatal paralytic illness caused by botulinum toxin which is a protein produced by the bacterium Clostridium botulinum under anaerobic conditions. The toxins enter the body either by ingestion of toxin from foods (food borne botulism) or by contamination of a wound by the bacterium (wound botulism). Usually in dogs it is related to ingestion of raw meat and dead animals. Typically, symptoms appear within a few hours to six days after eating spoiled animal meat that is infected with the Clostridium botulinum neurotoxin. This causes spreading weakness, starting in the back legs and ascending to the trunk, front legs and neck.
Dogs are generally resistant to the more severe effects of Clostridium botulinum. Mildly affected dogs recover over a period of several days with supportive treatment. However hospitalization may be required for dogs with difficulties breathing and in severe cases, paralysis can affect the ability to breathe and be fatal. Constipation may also be seen due to decreased peristalsis.