Linfadenite granulomatosa por Mycobacterium intracellulare em cão : relato de caso

Abstract

Mycobacteriosis is caused by bacteria belonging to the Mycobacterium genus, which have a considerable zoonotic potential and are a threat to public health. Infection in dogs is considered rare, is generally associated with immunosuppression, and results from contact with food products, soil, or fomites. The present report describes the clinical, laboratory, cytological, histopathological, and molecular findings of a male canine of the Lhasa Apso breed seen at a university veterinary hospital, and with generalised lymphadenomegaly associated with infection by Mycobacterium intracellulare. Histopathological examination of the submandibular lymph nodes using special Ziehl-Neelsen staining revealed a large amount of acid-resistant structures of the bacillary format in the macrophages and largely filling the cytoplasm. Polymerase chain reaction was used to amplify the DNA of the lymph node fragment for the hsp65 gene, which was subjected to genetic sequencing and construction of a phylogenetic tree with 99.77% genetic similarity for the species M. intracellulare. Mycobacterial infection is considered rare in dogs. However, sporadic cases can occur and represent considerable zoonotic potential. The correct diagnosis by means of cytological, histopathological, and molecular examination is of paramount importance, considering the potential transmission of the disease to humans and other animals.