Case Report: Diffuse Granulomatous Lymphadenitis in a Miniature Schnauzer Associated with Acid-Alcohol Resistant Bacillus (Mycobacterium avium) from Paraguay
M. avium is considered an emerging and opportunistic pathogen that can infect animal and human species. The dog has been seen as an animal resistant to infections by M. avium, cases have been reported in Miniature Schnauzers and Basset Hounds. It is believed that the cause would be a defect in the immune response of genetic origin with a pattern of autosomal recessive inheritance in Miniature Schnauzer bloodlines.
Describe a case of diffuse granulomatous lymphadenitis in a Miniature Schnauzer associated with BAAR.
Miniature Schnauzer, male, 2-year-old, for gradual weight loss, superficial adenopathy and intermittent lameness. All cytological lymph node samples were stained with 10% Giemsa and ZN; and evaluated by a 100x light optical microscope. The owner authorizes the necropsy, taking samples and corresponding studies of the pet.
Cytological samples from lymph nodes showed a poorly defined intracytoplasmic presence of refractive linear structures to pale basophils. ZN staining was positive by revealing the presence of BAAR in the macrophages.
The PCR technique using primers (Telenti 1993), where a pattern corresponding to Mycobacterium intracellulare type 1/Mycobacterium chimera type 1 is obtained, both correspond to the Mycobacterium avium complex. Both samples tested positive for this test.
This disease can present as a generalized lymphadenopathy, so a differential diagnosis should be made with lymphoma. This is the first report of a systemic infection of M. avium in a canine in the Paraguay and should be included as a differential diagnosis and zoonotic potential in immunocompromised persons.