Congenital feline tuberculosis: the first case report

This study presents the first report of congenital tuberculosis in an 8-month-old male British Shorthair cat. The case was examined using histopathological and immunohistochemical methods. The cat was referred to a private veterinary clinic with general respiratory system problems and subsequent deterioration, leading to death. The cat owner granted permission for the cat necropsy and pathological examinations at Department of Pathology, Faculty of Veterinary Medicine, Selçuk University, Konya, Türkiye. During systemic necropsy, white round foci with diameters ranging from 3.00 to 5.00 mm were observed in the lung and spleen. Tissue samples were collected from the lung, spleen, liver, heart, kidney, mediastinal lymph nodes and brain for histopathological examinations. The tissues were subjected to routine histological tissue processing and sections were stained with Hematoxylin and Eosin and Ziehl-Neelsen. Additionally, Mycobacterium spp. antibodies were used for immunohistochemical staining. Microscopic examination revealed exudative tuberculosis lesions, areas of necrosis without a fibrous capsule and karyorrhectic cells only in the lung and spleen. Acid-resistant bacteria observed by ZN staining in the lesioned areas of the lung and spleen were identified as Mycobacterium spp. using immunohistochemical staining. No positive staining was observed in other organs using ZN and immunohistochemical methods. As a result, congenital tuberculosis was diagnosed in a cat for the first time, especially in relation to lesions in the spleen.