Dogs may be infected with Mycobacterium tuberculosis, M bovis, and occasionally with M avium complex, commonly from a human, bovine or wildlife source, including bite wounds. Hereditarily immunocompromised breeds such as Miniature Schnauzers and Basset Hounds can be more susceptible to M avium.
Tuberculous lesions are usually found in the lungs, liver, kidney, pleura, and peritoneum, but locations such as the pericardium or bite wound abscesses have been recorded. Lesions can be calcified, with a necrotic center and usually a thin, fibrous layer. Tuberculosis is rare in dogs and can be subacute to chronic disease. Symptoms are nonspecific and depend on the location of the lesions. Tuberculosis should be suspected in dogs exposed to potentially infected humans, livestock, or wildlife and with abscesses nonresponsive to antibiotic therapy. Diagnosis may be assisted by radiography, echography, demonstration of mycobacteria by Ziehl-Neelsen coloration or PCR on biopsies or cytology specimens, and immunological tests such as lateral flow and IFNγ assays. False-negative tuberculin tests are often seen in dogs. Treatment can be effective in controlling disease progression but is often not performed, and the animals are euthanized for public health concerns.