Granulomatous lymphadenitis in a dog caused by Mycobacterium intracellulare

ABSTRACT

Background: Mycobacteriosis is caused by bacteria belonging to the genus Mycobacterium, with considerable zoonoticpotential and risk to public health. Infection in dogs is rare and is usually associated with immunosuppression, resultingfrom eating meat or contact with contaminated soil or fomites. Dogs are also known as potential sources for the spread ofatypical tuberculosis in humans and other animals. This paper aims to describe the clinical, cytological, histopathological,and molecular findings of a male canine seen at University Veterinary Hospital of Cuiabá, Mato Grosso, with generalizedlymphadenomegaly associated Mycobacterium intracellulare infection.Case A 2-year-old male Lhasa Apso dog was referred to the University Veterinary Hospital in Cuiabá city, located in theMidwest region of Brazil. The patient had a history of intermittent claudication of the left pelvic limb for approximately6 months and lymphadenomegaly with progression for approximately 2 months. The dog had wheezing and generalizedlymphadenopathy (submandibular, axillary, and popliteal lymph nodes); cryptorchidism was also observed. A completeblood count revealed nonspecific results, and in the serum biochemical profile, the values of urea, creatinine, albumin, andalanine aminotransferase were within the reference range. No changes were observed on the radiography of the femurotibiopatellar joints. Considering the generalised lymphadenopathy, fine needle aspiration cytology and histopathologicalexamination through biopsy of the lymph nodes was performed. On the cytology and histopathology, numerous negativeimages of moderately refringent bacillary structures distending the cytoplasm from the macrophages was found. Thesamples were also subjected to special Ziehl-Neelsen staining, which confirmed an accentuated and diffuse granulomatouslymphadenitis associated with alcohol...(AU)