There are many disorders that can affect multiple parts of the body. These may be caused by bacteria, viruses, poisonous or toxic substances in the environment, and other health hazards. Disorders affecting multiple body systems can also be inherited or develop while the animal is still in the womb. Diseases or conditions that involve multiple organ systems may also be described as systemic or generalized.

Many disorders are discussed in this chapter. A listing of congenital and inherited conditions is followed by a discussion of the most significant disorders, which have been arranged alphabetically by medical name to help you locate a particular disease or condition easily.

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