Meningeal tuberculosis in cattle

This communication describes a case of granulomatous meningitis in a crossbred cow, from Baidim municipality, Minas Gerais, Brazil. Clinically, the animal showed staggering gait, incoordination of the hind legs and decreased skin sensibility. These clinical signs progressed to sternal recumbency but the appetite and thirst were maintained. The animal died 30 days after beginning of the symptoms. Under post mortem examination enlargement of the internal and external lymph nodes was observed. Upon dissection, the lymph nodes showed caseous yellowish material replacing almost all the parenchyma. Granulomatous nodules ranging from 0.3 to 4cm, with the same gross aspect found in the lymph nodes, were observed in the lungs, liver, spleen, diaphragm and omentum The miliary nodules in the lungs were located mainly in the cranial lobes, and in the liver and spleen they were seen in the capsule and parenchyma as well. The involvement of the central nervous system occurred only in the meninges in the form of small nodules measuring around 2mm of diameter, which were located in the cerebral gyri sulcus (Fig. 1, white arrow). Also, there was conglomeration of tubercles in the leptomeninges of the mesencephalon (Fig. 1, dark arrow). Microscopy revealed a typical granulomatous inflammation in the cerebral meninges, with lymphocytes, epithelioid cells and Langhans giant cells infiltration (Fig. 2). Using Ziehl-Nielsen stain, it was possible to demonstrate red bacilli in epithelioid and giant cell cytoplasm. Based on gross and histological findings the diagnosis of tuberculous meningitis was made. In addition, toxicological examination of liver and gut contents, indicated a diagnosis of botulism. Thus, the cow presented pathology meriting diagnosis of both tubercular meningitis and botulism All clinical signs, however, could have been caused by botulism.