Prognostic factors for dogs with granulomatous meningoencephalomyelitis: 42 cases (1982-1996).

OBJECTIVE: To assess signalment, clinical signs, results of CSF analysis, treatment, and survival times in dogs with granulomatous meningoencephalomyelitis (GME) and to identify factors associated with survival. DESIGN: Retrospective study. SAMPLE POPULATION: Medical records of 42 dogs with GME. PROCEDURE: Information on signalment, neurolocalization, presence of focal or multifocal signs, results of CSF analysis, method of treatment, and time from onset of clinical signs to death was retrieved from medical records of each dog. Kaplan-Meier survival analysis was used to assess survival times. The Cox proportional hazards method was used to identify predictors of survival. RESULTS: Females and toy and terrier breeds were predisposed to GME. Half of the dogs had focal neurologic signs, and half had multifocal involvement. Clinical signs referable to the forebrain were most common with focal involvement, whereas signs referable to the forebrain and brainstem were most commonly seen with multifocal involvement. Cerebrospinal fluid analysis commonly revealed a mononuclear pleocytosis. Survival times ranged from 1 to > 1,215 days. Significant differences in survival times were demonstrated for the following factors: focal versus multifocal clinical signs, neurolocalization of focal signs, and treatment with radiation. Radiation was the only independent predictor of survival. CLINICAL IMPLICATIONS: Dogs with signs suggesting focal involvement of GME tend to survive longer than those with multifocal involvement. Radiation is an effective treatment for dogs with GME, particularly those with clinical signs suggesting focal involvement.

Deafness in the dog and cat.

Deafness in dogs and cats can be divided into two major categories: (1) conduction deafness and (2) sensorineural deafness. History and otic examination will often provide a diagnosis. Electrodiagnostic testing will confirm the deafness and further elucidate the specific cause. Therapy depends on the cause of the deafness and extent of involvement.

Neurological manifestations of Niemann-Pick disease type C in cats.

Seven Domestic shorthair cats with a lysosomal storage disorder analogous to human Niemann-Pick disease type C, from a breeding colony were studied to characterize the neurological manifestations of this disorder. Affected cats were identified by means of liver biopsies at 4 to 6 weeks of age. Neurological examinations were performed at 2 week intervals from the onset of clinical signs. All cats displayed signs referrable to the cerebellum, with a subtle intention tremor noticed initially at 8 to 12 weeks of age; the disease was rapidly progressive. The tremor became more pronounced, menace response was lost, and severe dysmetria and ataxia developed. Three cats also had signs referrable to other areas of the central nervous system. Cats died or were euthanized between 12 and 43 weeks of age. Pathological findings included accumulation of substrate within neurons throughout the central nervous system, and axonal spheroid formation. The clinical and pathological findings in these cats are comparable to those in the human form of the disease.

Neoplasms of the spine.

Although the treatment of central nervous system neoplasms generally is unrewarding, some animals with spinal neoplasia may, for a variety of reasons, be successfully managed for extended periods of time. The veterinary profession has greater experience with spinal surgery than with intracranial surgery. As a result, surgeons are more willing to attempt and more successful at removing or debulking spinal neoplasms. Additionally, there are more affordable and accessible diagnostic procedures available to evaluate the spinal cord than there are to evaluate the brain. Finally, the majority of tumors that affect the spinal cord are extramedullary and are therefore amenable to attempts to remove them surgically.

Multicentric osseous lymphoma with spinal extradural involvement in a dog.

Multicentric osseous lymphoma involving the ribs and multiple vertebrae was observed in a 7-year-old Siberian Husky. Extradural spinal cord compression was treated by surgical decompressive hemilaminectomy of L1-2 without noticeable improvement of signs neurologic dysfunction. However, palliation of signs of pain was noticed after irradiation in conjunction with chemotherapy and surgical decompression.

Heinz body hemolytic anemia associated with high plasma zinc concentration in a dog.

Acute zinc toxicosis from the ingestion of pennies was diagnosed in a dog with Heinz body hemolytic anemia (PCV = 14%), leukocytosis (51,000 cells/ml) with a left shift (3,060 band neutrophils; 37,740 segmented neutrophils) and monocytosis (4,080 cells/ml), azotemia (BUN = 60 mg/dl), bilirubinemia (total bilirubin = 5.3 mg/dl), hypokalemia (3.0 mEq/L), high serum alkaline phosphatase activity (691 U/L), high total plasma solids (8.1 g/dl), hemoglobinuria, and proteinuria. Despite aggressive medical treatment, renal failure ensued, and the dog died of cardiac arrest. The clinical signs, clinical course, and laboratory findings in this dog were similar to what has been reported in other cases of acute zinc toxicosis in dogs, with the exception of a history of generalized seizures and the findings of Heinz bodies. Although a causative relationship between plasma zinc values and Heinz body formation cannot be proven, their association suggests that oxidative damage to erythrocyte hemoglobin and cell membrane proteins may be involved in the pathogenesis of zinc-induced hemolysis.

Epilepsy. Clinical cases.

Several cases are presented to serve as examples of various diagnostic and therapeutic approaches used in handling epileptic patients. These cases should show a wide variation of clinical severity and therapeutic control. The success or failure to control seizure activity in each case is reviewed with the intention of providing helpful suggestions to practicing veterinarians faced with similar cases.

Disseminated sarcocystosis in a cat with lymphosarcoma.

Cysts of the protozoan Sarcocystis sp were found in skeletal and cardiac musculature in a 1.5-year-old cat with lymphosarcoma. The cat was FeLV-positive and had grossly visible neoplastic involvement of the spinal cord, mediastinum, bone marrow, and kidneys. Ultrastructural examination of the parasitic cyst wall suggested that the species in this case was different from that described in the only other reported case. It was hypothesized that immunosuppression from FeLV infection permitted an aberrant life cycle with encystment of Sarcocystis sp in this cat.

Neuroradiology.

Neuroradiographs are an invaluable part of the diagnostic plan in most cases involving nervous system dysfunction in companion animals. High MAS, low KvP techniques used on standard radiographic equipment available in most veterinary practices will provide good-quality neuroradiographs of the skull and spine. Proper positioning of the animal, which necessitates use of general anesthesia, is required to obtain neuroradiographs of good diagnostic quality. A working knowledge of the normal anatomy of the skull and spine is required to make correct interpretations of the neuroradiographs.

Inflammatory disease of the central nervous system.

Inflammatory diseases involving the central nervous system can be difficult to diagnose and frustrating to treat. The clinician can maximize successful treatment of these patients by recognizing the clinical signs in the early stages of disease, following a logical diagnostic plan to identify the specific etiologic agent involved, and formulating an appropriate and aggressive therapeutic plan. Treatment will not always be successful owing to lack of effective treatments and irreversible neurologic damage.

Insulinoma in a ferret.

Insulinoma was diagnosed in a 7-year-old female ferret examined because of generalized seizures, intermittent paraplegia, and abnormal behavior. Low serum glucose, high serum insulin, and infinite amended insulin/glucose ratio values in this ferret supported the clinical diagnosis of insulinoma. Histologic examination of the pancreas confirmed the diagnosis of insulinoma. The clinical signs and laboratory evaluations in this case and in a previously reported case of insulinoma in a ferret were consistent with variations reported in dogs with insulinoma.

Brain stem auditory-evoked responses in the dog.

Brain stem auditory-evoked responses (BAER) were recorded from 58 dogs that did not have a known history of hearing problems. The BAER wave forms had an overall mean amplitude approximately 3.0 microV and typically consisted of a series of 4 to 5 vertex-positive peaks (peaks I through V). When acoustic clicks having intensities of 60-dB hearing level (decibels relative to the subjective hearing threshold) were used as stimuli, peak I had a latency of 1.49 +/- 0.13 ms; peak II, 2.32 +/- 0.14 ms; peak III, 3.01 +/- 0.25 ms; peak IV, 4.22 +/- 0.27 ms; and peak V, 5.55 +/- 0.37 ms. Latency values were influenced by a number of nonpathologic factors, including stimulus intensity and the body temperature of the dog. As stimulus intensity was decreased, there was a lengthening of the latency of each peak coupled with a decrease in the overall amplitude of BAER. Decreases in rectal temperature caused a similar lengthening of peak latencies. Age may have an influence on BAER, but under the conditions of the present study, the effect was not significant.

Dysmyelination in Chow Chow dogs: further studies in older dogs.

The ultrastructure of myelin deficiency in Chow Chow dogs was studied in the spinal cord of a 15-month-old and a 3-year-old animal. It was found that myelination progresses with age in these dogs but is still deficient at the age of 3 years. The findings included axons with thin or uncompacted myelin sheaths, separated from each other by massive astrocytosis, and bizarre myelin formations. Normal numbers of morphologically normal oligodendrocytes were present in the myelin-deficient areas. The disease in these Chow Chow dogs consists of a strongly retarded myelination which is possibly due to a dysfunction or delay in glial maturation.

Bovine papular stomatitis incidence in veterinary students.

Five cases of probable bovine papular stomatitis in faculty and students in a university veterinary clinic precipitated an intensive surveillance program. A senior class of veterinary medical students was questioned at the beginning of their clinical training to determine their history of exposure to cattle and presence of lesions resembling bovine papular stomatitis. Fifty-nine of the 115 students reported having had their hands in the mouths of cattle frequently. One of the 59 had experienced a hand lesion resembling bovine papular stomatitis. This class was maintained under close surveillance for bovine papular stomatitis-like lesions during the final 12 months of their clinical experience in veterinary school. One case developed in 8483 person days spent in the three high risk areas of beef cattle service, dairy cattle service and large animal anesthesiology. These two bovine papular stomatitis cases compare in frequency with five class members who had been vaccinated as a result of exposure to rabid animals and two class members with brucella antibodies in their sera. The findings suggest bovine papular stomatitis infections are not unusual in veterinary students but the mild clinical manifestations make the condition relatively unimportant.

Distal symmetrical polyneuropathy in a dog.

A 1.3-year-old Great Dane dog had a chronic progressive neurologic disease clinically expressed as a distal symmetrical polyneuropathy characterized by weakness and bilateral atrophy of bulbar and distal appendicular musculature. Qualitative and quantitative studies showed neurogenic atrophy of muscles below the elbow and stifle. There was Wallerian-type degeneration, Schwann cell proliferation and cell bands of Büngner, and marked depletion of medium (5 to 8 microns) to large (9 to 15 microns) diameter myelinated fibers in the distal parts of appendicular and laryngeal nerves. Sensory (saphenous and superficial radial) and autonomic (sympathetic and dorsal vagal trunk) nerves were affected to a lesser degree. A distribution of distal axonal degeneration suggested a dying back process. The disease differed from classical dying back disorders by absence of axonal degeneration in selected pathways of the central nervous system.

Idiopathic facial paralysis in the dog.

Facial nerve paralysis of acute onset is reported in seven mature dogs, five of which were cocker spaniels. The clinical signs were characterised by ear drooping, lip commissural paralysis, sialosis, and collection of food on the paralysed side of the mouth. All dogs showed absent menace responses and trigeminofacial/acousticofacial reflexes. Horner's syndrome was not present in any dog. In four dogs, bilateral facial paralysis developed. The facial paralysis was unrelated to otitis media. Electrodiagnostic studies revealed denervation potentials and absent evoked muscle potentials. Facial nerve biopsies from two cases showed nerve fibre degeneration and apparent loss of larger diameter myelinated fibres. The condition has been termed idiopathic facial paralysis since the aetiopathogenesis is presently unknown.