Steroid responsive meningoencephalitis

Abstract

PHOTOS 1-2: Steroid responsive meningitis-arteritis (SRMA) is an immune mediated, inflammatory disease of the meninges and associated vasculature that is commonly documented in dogs. SRMA can occur in any breed of dog although some breeds like beagles, boxers, Bernese mountain dogs, Weimeraners and Nova Scotia duck tolling retrievers are more likely to be affected. Affected dogs may be seen to stand with an arched spine and be reluctant to walk as a result of pain. Furthermore, the dog may refuse to eat or drink unless the bowl is raised to head level. Two clinical forms of steroid responsive meningitis-arteritis are presented : a classical acute form and a less common chronic form. Typical symptoms of the acute form include hyperesthesia along the vertebral column, cervical rigidity, a stiff, hunched gait and fever. High immunoglobulin A concentrations in both serum and cerebral spinal fluid are typically found in affected dogs, and may aid in diagnosis. Polymorphonuclear pleocytosis, elevated protein and variable red blood cells are present in the cerebral spinal fluid (CSF). In severe cases, banded or segmented neutrophils may be observed in the CSF. Bacterial cultures will be negative and cervical vertebrate radiographs normally ruling out bacterial meningitis and damage to the cervical vertebrae. Dogs with acute SRMA that are treated with early anti-inflammatory and/or immunosuppressive therapy (Prednisone) generally recover well. Cerebral spinal fluid should be normal before discontinuing prednisone therapy. Additional immunosuppressive therapy like mycophenolate, azathioprine or cyclosporine may be required for the chronic form.

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