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.     

Central nervous system lymphosarcoma in the dog

Central nervous system lymphosarcoma was diagnosed in 8 dogs with seizures and clinical signs compatible with multifocal central nervous system involvement. Cerebrospinal fluid analysis showed high white cell counts with abnormal lymphoid cells in all dogs, and high protein concentration in 5 dogs. Two dogs were given systemic anticancer chemotherapy, and 4 dogs were given a combination of systemic chemotherapy, intrathecal cytosine arabinoside, and craniospinal irradiation, resulting in marked improvement of the clinical signs.     

Acute bilateral trigeminal neuropathy associated with nervous system lymphosarcoma in a dog

A nine-year-old dog presented with clinical signs consistent with bilateral trigeminal neuropathy. Multicentric lymphoma was diagnosed, and neoplastic lymphocytes were identified in the cerebrospinal fluid. Electromyography revealed spontaneous activity in temporal and masseter muscles. Histopathological examination demonstrated neoplastic cell invasion of temporal and masseter myofibers and of multiple peripheral nerves, including the trigeminal nerve. Central nervous system pathology consisted primarily of spinal root and leptomeningeal lymphoid cell infiltration with relative sparing of spinal cord and brain parenchyma.     

Central nervous system infection with Staphylococcus intermedius secondary to retrobulbar abscessation in a dog

In this report, we describe a case of retrobulbar abscessation in a dog that was initially diagnosed as masticatory myositis and treated with immunosuppressive doses of corticosteroids. Secondary bacterial infection of the central nervous system (CNS) occurred and was definitively diagnosed by the analysis and culture of the cerebrospinal fluid. This is the first time that retrobulbar infection has been definitively shown to result in secondary bacterial infection of the CNS in the dog and highlights the importance of ruling out infectious causes of retrobulbar disease before assuming and treating for an immune-mediated etiology.     

Toxicosis associated with ingestion of quick-dissolve granulated chlorine in a dog

CASE DESCRIPTION: A dog was referred for treatment after ingestion of quick-dissolve chlorine granules intended for use in a swimming pool. CLINICAL FINDINGS: At evaluation 18 hours after ingestion of the granules, the dog had tachypnea, signs of depression, approximately 5% dehydration, oral mucositis, and a productive cough. Increased respiratory tract sounds and wheezes were ausculted in all lung fields. Complete blood count revealed erythrocytosis and lymphopenia. Serum biochemical analyses revealed mildly high activities of hepatic enzymes and creatine kinase. Arterial blood gas concentrations were consistent with hypoxemia and hyperventilation. Thoracic radiography revealed widespread pulmonary alveolar infiltrates predominantly affecting the ventral portions of both lungs, consistent with noncardiogenic pulmonary edema secondary to aspiration of the granulated chlorine. TREATMENT AND OUTCOME: Initial treatment included IV administration of an electrolyte solution with supplemental KCl, ranitidine, furosemide, cefotaxime, buprenorphine, and supplemental oxygen. Subsequent treatment included administration of meloxicam and an endoscopically placed percutaneous gastrostomy tube. Endoscopic examination revealed esophagitis and mild gastritis; therefore, metoclopramide and sucralfate were also administered. Fifteen days later, the gastrostomy tube was removed prior to discharge; endoscopic examination revealed grossly normal esophageal and gastric mucosa, and thoracic radiography revealed complete resolution of the lung lesions. CLINICAL RELEVANCE: Although ingestion of granulated chlorine is rare in veterinary patients, the resulting disease processes are common and can be treated successfully.     

Granulomatous meningoencephalomyelitis with peripheral nervous system involvement in a dog

A 9-year-old male neutered Labrador Retriever presented with signs consistent with multifocal neurological disease. Cerebrospinal fluid analysis revealed a mononuclear pleocytosis and electromyography revealed abnormal electrical activity in distal appendicular and masticatory muscles. Treatment was declined and necropsy revealed disseminated granulomatous meningoencephalomyelitis with extensive involvement of the peripheral nervous system.     

Apparent toxicosis associated with lily-of-the-valley (Convallaria majalis) ingestion in a dog

Lily-of-the-valley (Convallaria majalis), an ornamental plant found in many urban settings, was believed responsible for the sudden collapse and death of a one-year-old mixed-breed dog. Postmortem examination revealed C majalis leaf fragments in the small intestine. The dog had gross and histologic lesions consistent with cardiac shock. Because C majalis contains cardiac glycosides that have digitalis-like activity, apparent C majalis intoxication was suspected in this dog on the basis of history, exposure to the plant, clinical signs of disease, postmortem lesions, and evidence of plant parts in the intestinal tract. A toxicologic assessment of excessive exposure to C majalis was based on the aforementioned criteria.     

Central nervous system cryptococcoma in a cat

This report describes the gross, histopathological, immunohistochemical and electron microscopic findings in a 4-year-old cat with systemic Cryptococcus neoformans infection. A 1-cm diameter pontine mass, pinpoint lesions in the cerebellum and in the right kidney were the main macroscopic findings. A presumptive diagnosis of cerebral neoplasia with metastasis was formulated. Light microscopy revealed a huge number of yeasts surrounded by a pyogranulomatous inflammatory reaction in the cerebral parenchyma and, to a lesser extent, in the kidney, while the meninges were not involved. The positive mucicarmine stain that coloured the capsule of the yeasts was indicative of cryptococcal infection. Immunohistochemistry confirmed the presence of C. neoformans var. grubii (C. neoformans serotype A). Electron microscopy revealed yeasts with a massive fibrillar capsule and lamellar cell wall free in the cerebral tissue and within macrophages.     

Hep atop athy and dermatitis in a dog associated with the ingestion of mycotoxins

A five-year-old German shepherd dog was presented with a severe scrotal dermatitis of four weeks duration which had failed to respond to antibiotic and corticosteroid therapy. Dermato-histopathology indicated that the lesion was a necrolytic process suggestive of the hepatocuta-neous syndrome. Clinical biochemistry investigations indicated the presence of acute hepatocellular damage and cholestasis. The animal was fed a biscuit meal which was damp and mouldy. Penicillium vindication was grown from this feedstuff and three mycotoxins, citrinin, ochratoxin A and sterigmatocystin, were found; substances which have been associated with renal and hepatic lesions in dogs and laboratory animals. Symptomatic therapy and nutritional management, led to rapid clinical improvement. Subsequent plasma biochemistry confirmed that hepatic enzyme activities were returning to normal levels.     

Central nervous system dysfunction associated with Rocky Mountain spotted fever infection in five dogs

Five dogs from the northeastern United States were presented with clinical signs of neurological disease associated with Rocky Mountain spotted fever (RMSF) infection. Four of the five dogs had vestibular system dysfunction. Other neurological signs included paresis, tremors, and changes in mentation. All of the dogs had an elevated indirect fluorescent antibody titer or a positive semiquantitative enzyme screening immunoassay titer for Rickettsia rickettsii at the time of presentation. Although a higher mortality rate has been reported for dogs with neurological symptoms and RMSF infection, all of the dogs in this study improved with appropriate medical therapy and supportive care.     

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.     

Central nervous system trauma

Traumatic injury to the central nervous system causes immediate damage and sets in motion a complex series of pathophysiologic events that result in further neuronal injury. This secondary damage seems to be related to changes in blood flow and pressure on a systemic, regional, and microvascular level. Currently, there is evidence that these changes are, in part, mediated by endogenous opioids and arachidonic acid metabolites, namely thromboxane A2. Medical management is generally designed to intervene at one or more stages in this secondary cascade of events. Further research should lead us to better understanding of the mechanisms involved in trauma to the central nervous system and, subsequently, more specific and effective treatments.     

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.     

Central diabetes insipidus in a cat with central nervous system B cell lymphoma

A 6-year-old male neutered cat presented with blindness, lethargy, polydipsia, hyposthenuria and severe hypernatraemia. Central diabetes insipidus was demonstrated by means of a low measured anti-diuretic hormone (ADH) concentration in the face of hypernatraemia, and clinical response to supplementation with desmopressin. Magnetic resonance imaging of the brain showed a discrete mass in the region of the hypothalamus. The cat was euthanased and post-mortem histological examination demonstrated B cell lymphoma involving the brain, optic nerves, urinary bladder wall and diaphragm. To the authors' knowledge, this case report is the first to describe central diabetes insipidus caused by central nervous system lymphoma in the cat.     

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.