A retrospective study of 286 cases of neurological disorders of the cat

Abstract

Archive central nervous tissue from 286 cats with neurological disorders was reviewed for histological evidence of feline spongiform encephalopathy (FSE), which may have occurred before it was first recognized in 1990. The following six categories of disease were identified: congenital; degenerative; inflammatory; neoplastic; FSE; lesion-free. The largest category (inflammatory) contained 92 cats, of which 47 were considered to be consistent with infection by feline infectious peritonitis (FIP) virus. Six cats showed evidence of more than one disease process; thus, one cat with FIP also had toxocara infection of the lateral ventricles and five cats with FSE also showed perivascular cuffing suggestive of concurrent viral infection. In only two cases did the diagnosis on review differ significantly from the original interpretation. There was no evidence of FSE before the original case was recognized in April 1990.

Fig. 1

Cat brain, medulla. Lysosomal storage disease: floccular appearance of neuronal cytoplasm (arrow). HE. ×400.

Fig. 2

Cat brain, lateral ventricle. Incidental infection with nematode (Toxocara) larvae. HE. ×400.

Fig. 3

Cat brain, cerebrum. Protozoal tissue cysts (arrows) associated with glial reaction. HE. ×400.

Fig. 4

Cat brain, mid cerebrum, meninges. Cryptococcal organisms (arrows) associated with a granulomatous, inflammatory cell infiltrate. Periodic acid-Schiff. ×150.

Fig. 5

Cat brain, medulla. Meningoencephalitis. Mixed inflammatory cell infiltrate. HE. ×150. Inset: coccoid bacteria in the inflamed area. EM. ×4500.

Fig. 6

Cat brain, thalamus. Feline immunodeficiency virus infection: bizarre giant cells are present (arrow). HE. ×400.

Fig. 7

Cat brain, thalamus. Feline spongiform encephalopathy with possible co-existent viral infection, indicated by perivascular lymphoid cuff (lower right). Vacuolated neuron (arrow). HE. ×400.