Three cats were presented with neurological deficits compatible with cerebral disease. Two of the cats had temporal lobe infarction diagnosed as ischaemic encephalopathy; one cat had granulomatous inflammation, diagnosed as focal granulomatous meningoencephalitis. In all three cases the lesions were characterized by necrotic, cavitated areas. Vascular insult was the cause of the ischaemic encephalopathy and the focal granulomatous meningoencephalitis may have been caused by feline infectious peritonitis (FIP) virus. An infectious aetiology, possibly FIP virus, is proposed for the ischaemic encephalopathy. A relationship between these two neurological diseases may exist.

The small animal practitioner is faced with an infinite number of potential toxins in our modern environment. Unapproved usage of drugs and insecticides requires the practitioner to keep informed about the development of new toxic syndromes. Recreational drug toxicosis in animals is still seen with some frequency in clinical practice and should not be overlooked, even when the owner denies the possible exposure. In this article, we have discussed a few of the more common and newer neurotoxicities seen in clinical practice today. Neurologic toxicities are complex, but treatment can be rewarding if early diagnosis is made and aggressive therapy is instituted. The practitioner will find it worthwhile to establish contact with a toxicologist or poison information center for additional support when necessary.

Nervous system diseases of the cat are being recognized with increasing frequency owing to both advances in our understanding of cat diseases and the willingness of the public to pursue diagnostic examinations and procedures. Hopefully, in the future, many large case studies will help define the frequency, clinical presentation, and signalment for these diseases.The following discussion will concern a few neurologic diseases that affect the cat. The specific disease, its pathogenesis, diagnosis, and treatment will be emphasized. MENINGIOMASPathologic features of spontaneous central nervous system tumors have been the subject of several reviews. 13 • 21 These studies discussed the relative incidence and morphology of central nervous system tumors. Based on necropsy findings, the meningioma is the most common central nervous system tumor of the cat. 13 • 21 One report indicated their incidence as 0. 9 per cent of all nonhematopoietic neoplasms. 21 The meningioma is a benign tumor that arises from the arachnoid cells of the meninges, which are mesodermal in origin: Compared to the dog, neuroectodermal tumors in the central nervous system are relatively rare in the cat. The vast majority of meningiomas occur cranial to the foramen magnum; therefore, accompanying signs suggest brain, rather than spinal cord, disease. 13 • 15 In one study, 25 of 30 solitary meningiomas arose from the supratentorial calvarium, compressing the cerebrum. 15 Although these tumors are benign, they cause devastating effects through compression and displacement of the surrounding nervous tissue, which is encased by the nonexpansive cranium. Edema of the nervous tissue is also a complication of the tumor, and often the signs observed are due to the edema rather than to the tumor mass itself. 6 The pathogenesis of this is unclear. In man, edema is not apparently due to increased vascularity, location, or histology of the meningioma but