The signs of meningitis are often easy to detect. If a veterinarian sees a dog with fever, stiffness, painful spasms in the back, rigidity of the muscles of the neck and forelimbs and extreme sensitivity to touch (called “hyperesthesia”), she probably will begin her diagnostic process by running blood and urine tests to detect possible causes of those signs. If the results of those tests are normal, she may prescribe medications on the assumption that the signs are caused by meningitis. This is called diagnosis by response to treatment. If the medication works, then the dog probably was suffering from meningitis.
In some cases, the veterinarian or owner wants at least a tentative diagnosis before treatment begins. Very few tests are available to diagnose meningitis. They ones that are available include computed tomography (CT or CAT scan), magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) tap and sample assessment. Blood tests can also help to narrow down or possibly identify the actual cause of a dog’s neurological condition. A CT/CAT scan or MRI, if available, will allow the veterinarian to visualize inflammation of the meninges, which are the tissue layers surrounding the brain and spinal cord. If inflammation is not seen, this will almost always rule out meningitis as a cause of the dog’s clinical signs.
Analysis of cerebrospinal fluid obtained by a spinal tap can be diagnostic as well. A sample of the cerebrospinal fluid which coats the brain and spinal cord can help with the diagnosis. This procedure involves collecting cerebrospinal fluid through a needle inserted between several of the vertebrae in the dog’s back. The fluid is analyzed microscopically for evidence suggestive of meningitis. During this procedure, the dog will be under general anesthesia. These tests are expensive, and they are not widely available. The only way to truly definitively diagnose canine meningitis is by histopathologic examination of affected brain and/or spinal cord tissue, which is not normally done in a clinical setting. It usually is done post-mortem.
Meningitis is a life-threatening condition. If a dog displays signs consistent with meningitis, its owner should please make an immediate visit to a veterinarian. Early diagnosis is essential for successful treatment and recovery.