Marked MMP-2 transcriptional up-regulation in mononuclear leukocytes invading the subarachnoidal space in aseptic suppurative steroid-responsive meningitis-arteritis in dogs.

Canine Steroid-Responsive Meningitis-Arteritis (SRMA) is a suitable animal model for studies on the development of neutrophilic pleocytosis in aseptic meningitis. Samples of dogs in the acute phase of SRMA (n=16) were examined for gene expression of matrix metalloproteinases (MMP)-2 and -9 and tissue inhibitors of metalloproteinases (TIMP)-1 and -2. Results were compared to those of dogs under glucocorticosteroid treatment for SRMA (n=16) and dogs with other inflammatory and neoplastic diseases of the central nervous system (CNS) (n=19). Samples included mononuclear (PBMCs) and polymorphonuclear cells (PBPMNs) of peripheral blood and cerebrospinal fluid white blood cells (CSF WBCs). In the acute phase of SRMA CSF WBCs showed mRNA expression for MMP-2 and -9 and TIMP-1 and -2, highlighting a contribution of these cells to the overall content of MMPs and TIMPs in CSF. MMP-2 mRNA levels in CSF WBCs were significantly up-regulated in comparison to PBMC expression levels, suggesting that MMP-2 is relevant for PBMC invasion into the subarachnoidal space and that the expression is influenced by migratory activity through the blood-CSF-barrier.

A retrospective epidemiological study of clinical signs and familial predisposition associated with aseptic meningitis in the Norwegian population of Nova Scotia duck tolling retrievers born 1994-2003.

Aseptic meningitis (AM) is a disease that causes grave clinical signs such as intensive neck pain, fever, and lethargy. The severity of this disease is reflected in the fact that affected animals require long-term, and in chronic cases, lifelong therapy with corticosteroids. A number of dogs must be euthanized because of therapeutic failure. In recent years, the Norwegian population of Nova Scotia duck tolling retrievers has experienced an increase in individuals with AM. The aim of the present study was to investigate the prevalence of AM and to pursue the suspicion of hereditary factors influencing an accumulation of AM cases in the breed. Using the Norwegian Kennel Club registery, a random sample (362 dogs) stratified by year of birth was drawn from the total population born from 1994 to 2003 (1525 individuals). The owners were contacted and questioned about clinical signs of AM in their dogs. Subsequently, the practising veterinarians and the breeders of positive responders were contacted in order to confirm a clinical diagnosis of AM and to identify possible affected family members. Pedigrees of AM positive individuals and affected relatives were investigated. The study estimated a prevalence of AM of 2.5%. For all affected dogs, it was possible to trace the pedigree of both parents of affected dogs back to a specific founder dog. The genealogical investigation strongly indicates that genetic factors are involved in the etiology of the disease.

Aseptic suppurative meningitis in juvenile boxer dogs: retrospective study of 12 cases.

Immune-mediated central nervous system inflammation is described in a series of 12 juvenile boxer dogs. A diagnosis of steroid-responsive meningitis-arteritis was made based on the clinical presentation and on diagnostic findings. The boxer breed was at a higher risk for this inflammatory condition than other breeds. Long-term follow-up (>2 years) confirmed a better prognosis in this breed than in the beagle and the Bernese mountain dog. Complete resolution of clinical signs without significant deficits or recurrences was obtained in all cases. Early clinical recognition and immunosuppressive treatment resulted in a better response and complete resolution of the disorder.

Herpes simplex encephalitis in a domestic rabbit (Oryctolagus cuniculus).

An adult domestic rabbit showing neurological signs was subjected to euthanasia. At necropsy, macroscopical lesions were absent. Histopathologically, extensive lesions were seen, particularly in the cerebral cortex. Non-suppurative meningitis was present and there was lymphocytic and plasmacytic perivascular cuffing in the neuropil. The cerebral cortex showed extensive segmental neuronal and glial necrosis. Within the necrotic areas, large amphophilic intranuclear inclusion bodies were present in neurons and glial cells. Immunohistochemically, neurons and glial cells in the affected areas were labelled by polyclonal antibodies against both herpes simplex virus-1 (HSV-1) and HSV-2. The agent was classified as HSV-1 by polymerase chain reaction analysis. This is only the second reported natural case of herpes simplex infection in a rabbit.

Juvenile-onset polyarthritis syndrome in Akitas.

Two young Akitas were examined because of manifestation of a juvenile-onset form of polyarthritis. A search of medical records at the New York State College of Veterinary Medicine found 6 more similarly affected Akitas. The clinical manifestations were marked by cyclic febrile illness and signs of profound joint-related pain. Two dogs had concurrent aseptic meningitis. The syndrome resembles juvenile rheumatoid arthritis in human beings, although it shares features with systemic lupus erythematosus. Pedigree analysis of affected Akitas supported a heritable component to the syndrome. Treatment with immunosuppressive drugs was effective in 2 dogs that achieved complete remission, and in 2 dogs that achieved only partial remission. Classification of this syndrome is difficult and may represent an "overlap" syndrome commonly described in human beings.

Neurotoxicologic effects of the nonionic contrast agent iopamidol on the leptomeninges of the dog.

The effect of iopamidol on the leptomeninges was tested and compared with that of metrizamide and normal saline solution in 18 dogs. Pathologic and clinical effects were evaluated at 24 hours and 14 days after cisternal injection of iopamidol, metrizamide, or normal saline solution. Pathologic changes were evaluated by microscopic examination of serial CSF samples and of sections of brain and spinal cord with the leptomeninges intact. Clinical changes were subjectively evaluated. Electromyograms and EEG were performed on each dog after physical and neurologic examination. There were no changes seen in neurologic status, electromyogram, or EEG in any of the dogs immediately after subarachnoid injection nor at 24 hours or 14 days later. Pathologic changes were limited to mild, moderate, or severe patchy hemorrhagic leptomeningitis seen at 24 hours after iopamidol or metrizamide was injected. The severity of changes were judged to be similar with both these agents. The CSF analysis and histologic evaluation of brain and spinal cord sections revealed a neutrophilic response to iopamidol and a mononuclear response to metrizamide. These findings indicate that iopamidol has minimal neurotoxicologic effect on the leptomeninges and therefore has merit as a myelographic agent.