Botulism is a motor paralysis caused by eating food containing the toxin (a poisonous substance) produced by Clostridium botulinum. This bacterium grows rapidly in decomposing animal tissue and sometimes in plant material. It results in rapid death due to the paralysis of vital organs. Botulism is not an infection. The paralysis is caused by the consumption of the toxin in food.

There are 7 types of Clostridium botulinum; the C₁ type is most common in animals. The usual source of the toxin is decaying carcasses or spoiled vegetation. Botulism occurs only sporadically in dogs.

The signs of botulism are caused by muscle paralysis and include progressive motor paralysis, disturbed vision, difficulty chewing and swallowing, and progressive weakness. Death is usually due to paralysis of the lungs or heart. Treatment is usually not possible, although a few experimental therapies have had limited success.

Last full review/revision July 2011 by Otto M. Radostits, CM, DVM, MSc, DACVIM (Deceased); David A. Ashford, DVM, MPH, DS; Craig E. Greene, DVM, MS; Eugene D. Janzen, DVM, MVS; Bert E. Stromberg, PhD; Max J. Appel, DMV, PhD; Stephen C. Barr, BVSc, MVS, PhD, DACVIM; J. P. Dubey, MVSc, PhD; Paul Ettestad, DVM, MS; Kenneth R. Harkin, DVM, DACVIM; Delores E. Hill, PhD; Johnny D. Hoskins, DVM, PhD; Jodie Low Choy, BVMS; Barton W. Rohrbach, VMD, MPH, DACVPM; J. Glenn Songer, PhD; Joseph Taboada, DVM, DACVIM; Charles O. Thoen, DVM, PhD; John F. Timoney, MVB, PhD, Dsc, MRCVS; Ian Tizard, BVMS, PhD, DACVM