Nocardiosis is a chronic, noncontagious disease caused by the bacteria of the genus Nocardia. These bacteria are found commonly in soil, decaying vegetation, compost, and other environmental sources. They enter the body through contamination of wounds or by inhalation. Species in this genus are found in temperate regions, as well as in tropical and subtropical areas.

Poor appetite, fever, lethargy, and weight loss are common nonspecific signs associated with all infection sites. Infections in dogs are often localized, with lesions beneath the skin, mycetomas, and inflammation of one or more lymph nodes. There may be swelling and inflammation of the gums around the teeth and ulcers in the mouth accompanied by severe bad breath. Nocardiosis affecting the chest often involves pus-producing inflammation of the chest cavity or abdominal cavity. The heart, liver, kidneys, and brain may also be affected. Occasionally, young dogs have a form of disease that begins in the lower respiratory tract after inhalation of the organism and spreads throughout the body.

Your veterinarian will prescribe antibiotics based on identification of the bacteria. Nocardial infections are resistant to some types of antibiotics. Treatment must often be continued for more than 3 months. It is important to continue treatment as directed to allow your pet the best possibility for recovery. The prognosis is guarded due to the long treatment time and the likelihood of relapse.

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