Cryptococcosis of the central nervous system in a dog

A 3-year-old female German Shepherd Dog was evaluated for progressive mental obtundation and vestibular signs. Central nervous system cryptococcosis was diagnosed on the basis of growth of Cryptococcus neoformans in fungal culture of CSF, as well as detection of the organism in CSF via microscopy. Cryptococcal capsular latex antigen agglutination titer was 1:262,144 in CSF and 1:1,048,576 in serum samples. Imaging with magnetic resonance augmented diagnosis. The dog improved after long-term treatment with fluconazole. Fluconazole is useful in the treatment of CNS cryptococcosis, because it attains high concentration in the CNS. Long-term therapy is often required for resolution of clinical signs, and affected animals may require long-term follow-up with periodic evaluation of CSF via fungal culture and latex agglutination tests. Monitoring serum latex agglutination test results may provide a safe, less invasive means of monitoring response to treatment.     

Reticulosis of the eyes and the central nervous system in a dog

Bilateral optic neuritis was diagnosed in a 5-year old dog, which had been blind for two days. Vision returned after corticosteroid therapy. Two weeks after the end of this treatment the dog became blind again and, in addition, showed ataxia. Post-mortem examination revealed changes in both the central nervous system and the eyes. The histopathological changes observed were consistent with those of reticulosis.     

Primary T-cell lymphoma of the central nervous system in a dog

Primary T-cell lymphoma is a rare form of CNS neoplasia. Diagnosis may be aided by use of cytologic examination of CSF. Primary CNS T-cell lymphoma should be considered in a patient with multiple cranial nerve abnormalities, even if results of imaging studies are considered normal.     

Primary central nervous system B-cell lymphoma in a young dog

This report describes a primary central nervous system B-cell lymphoma in a 3-year-old intact female Maltese dog. Canine primary central nervous system lymphomas constitute about 4% of all intracranial primary neoplasms, but comprehensive histopathologic classifications have rarely been carried out. This is the first report of this disease in a young adult dog.     

Fungal infections of the central nervous system in the dog and cat

Fungal infections of the central nervous system (CNS) in dogs and cats are uncommon. The purpose of this paper is to review the clinical signs, diagnostic tests, and therapeutic options of fungal infections of the CNS in the dog and cat. Clinical signs are dependent on lesion location and are often multifocal. Extraneural involvement is common. Antemortem diagnosis can be difficult and is definitively made via cytology, biopsy, or culture of an affected organ or cerebrospinal fluid (CSF). Magnetic resonance imaging can support a diagnosis and may assist in therapeutic decisions. Fungal serology can support a diagnosis when direct visualization of the organism is not possible. Long-term azole maintenance therapy is suggested to enhance survival and prevent relapse. Serial cerebrospinal fluid evaluation and magnetic resonance imaging may identify early relapse.     

Cryptococcal infection of the central nervous system of a dog in the United Kingdom

Cryptococcal infection of the C.N.S. is described in a two-year-old Borzoi dog. The animal showed limb weakness progressing over a period of five months to spastic paraplegia with head tremor, stiffness of the neck and nystagmus. On post-mortem examination there was severe hydrocephalus and granulomatous ependymitis. Cryptococci were found in the lesions and were identified on the basis of morphology and reaction to specific fluorescent antibody. This is believed to be the first case of canine cryptococcosis reported in the United Kingdom.     

Vasculitis in a dog resembling isolated angiitis of the central nervous system in humans

An 1-year-old dog succumbed to a seizure disorder of 18 days duration. At necropsy, an area of hemorrhage and discolored parenchyma was identified in the left pyriform lobe of the brain. Microscopic examination revealed a localized, necrotizing vasculitis with associated cerebral necrosis. Vasculitis was not present in other organs. This presentation is consistent with isolated central nervous system (CNS) angiitis, a rare form of vasculitis in humans.     

A case of primary hypothyroidism causing central nervous system atherosclerosis in a dog

A 2-year-old, castrated male, Australian shepherd was presented with a history of chronic mild ataxia, obesity, and lethargy. The dog was treated with levothyroxine, but the ataxia worsened. Cranial nerve abnormalities developed and the dog was euthanized. Postmortem examination revealed marked thyroid gland atrophy and widespread, severe central nervous system atherosclerosis.     

Central nervous system blastomycosis in a dog

An adult golden retriever was presented for progressive neurologic dysfunction. Clinical examination suggested brainstem disease. Blastomycosis was diagnosed based on fine-needle aspiration cytology of a normal sized lymph node and a positive blastomycosis urine antigen test. Systemic blastomycosis with neurologic involvement was confirmed at necropsy.     

Nutritional and metabolic diseases involving the nervous system

This article will discuss eight diseases that alter normal nervous system function: hypovitaminosis A, water deprivation/salt toxicity, ammonia toxicosis, hypomagnesemia, hypocalcemia, nervous ketosis, hepatoencephalopathy, and rumen metabolic acidosis.