Aseptic Meningitis in Dogs

Overview of Canine Aseptic Meningitis

Meningitis is an inflammation of the meninges, which are three membranes covering the brain and spinal cord. There are many causes of meningitis including viral, bacterial, fungal, and immune mediated in dogs.

Aseptic meningitis is believed to be an immune-mediated disease of dogs although the exact cause is unknown. It is most frequently seen in medium to large breed dogs. Aseptic meningitis usually affects dogs younger than two years old with both male and female dogs equally affected.

Other diseases that may mimic this disease include viral, bacterial and fungal meningitis. Brain tumors and hydrocephalus may also show similar signs.

What to Watch For

Signs of meningitis in dogs may include:

Fever
Neck pain

Clinical signs may wax and wane spontaneously.

Diagnosis of Aseptic Meningitis in Dogs

Diagnostic tests are needed in addition to obtaining a complete medical history. The most commonly performed tests include a neurological assessment, laboratory evaluation and cerebrospinal tap (CSF).

The CBC may show a high white blood cell count of mainly neutrophils.
The CSF tap typically has a very high cell count and protein level but no infectious organisms are seen.

Treatment of Aseptic Meningitis in Dogs

Treatment for aseptic meningitis may include treatment with immunosuppressive drugs. The common drug used is prednisone. Side effects from the medications include increased eating, drinking, urinating, and panting.
Response to treatment is typically seen within 24 to 48 hours of starting medications.
Medications must be given long term; more than four weeks is typical. Medication is generally tapered gradually to alternate days over the course of treatment, usually several months. Relapses may occur during the tapering course. Relapses usually respond to increasing the medication dose.

Home Care

If your pet is showing signs of meningitis, you should contact your veterinarian immediately. There is no appropriate home care for this potentially life threatening illness.

If your veterinarian prescribes a medication, it is important to follow directions unless specifically told to change medication dosage or type.

Observe your pet closely for any worsening of clinical signs. If you notice any deterioration in your pet’s condition, especially during the taper, contact your veterinarian immediately.

Prognosis

Treatment of aseptic meningitis is successful in the vast majority of animals. Relapses are typically seen if the medications are withdrawn too rapidly. Dogs that relapse will typically respond to treatment with either higher doses of the initial drug or addition of a second drug.

In-depth Information on Aseptic Meningitis in Dogs

Meningitis is an inflammation of the meninges, which is the fibrous covering of the brain and spinal cords. There are many causes of meningitis including viral, bacterial, fungal and immune mediated.

Aseptic meningitis is believed to be an immune-mediated disease although the exact cause is unknown. The meninges become inflamed and thickened with an invasion of inflammatory cells. This usually occurs in the neck. The signs that your pet reflect the location of the inflamed meninges and vary from mild neck discomfort to severe cervical rigidity and intractable pain. Fever may accompany the signs of pain.

It is most frequently seen in medium to large breed dogs. Dog breeds that are seen most often are:

Labrador retrievers
Golden retrievers
Bernese Mountain dogs
Weimaraners
German shepherd dogs

Aseptic meningitis usually affects dogs younger than two years old with both male and female dogs equally affected.

Aseptic meningitis may be the most common form of meningitis seen in dogs. Dogs affected by aseptic meningitis usually do not show other signs of bacterial meningitis. Other conditions that can cause similar signs include:

Viral meningitis. This form can be caused by canine distemper, adenovirus, or rarely parvovirus.
Bacterial meningitis. Although rare, Staphylococcus intermedia, streptococcus, Escherichia coli and Pasteurella multocida are all bacteria that can cause bacterial meningitis.
Other infections causes of meningitis include Rickettsia (Rocky Mountain Spotted Fever), fungus (Cryptococcus neoformans) and parasites. These can cause meningitis but usually have other signs of illness.
Brain tumors. Tumors of the forebrain can cause neck stiffness or pain.
Hydrocephalus and syringomyelia. These are congenital (present at birth) conditions typically seen in smaller dog breeds.

Veterinary care should include diagnosis and treatment.

In-depth Information on Diagnosis

Diagnostic tests are needed to determine your pet’s general health and to rule-out other diseases that may mimic aseptic meningitis. In addition to obtaining a complete medical history and physical examination your veterinarian will perform the following tests:

Neurological assessment to evaluate your dog’s neurologic system
Ophthalmologic examination to evaluate your dog’s visual system especially the fundus, or the back of the eye
Laboratory evaluation, including a CBC, chemistry profile and urinalysis

With aseptic meningitis the commonly found abnormalities on the history, physical and neurological examination include fever, lethargy, neck pain and anorexia. There should be no other neurologic abnormalities found besides neck discomfort and proprioceptive deficits (placement of feet). Abnormalities found on the lab tests may include high white blood cell count, and decreased platelet counts. Other abnormalities may be found secondary to the illness.

Cerebrospinal tap (CSF) evaluating the cerebrospinal fluid that bathes the CNS. A CSF tap requires anesthesia, and the analysis of the fluid must be performed promptly to prevent errors. The CSF tap is typically inflammatory with no bacteria, virus, fungus or other cause visible. The CSF may be cultured to make sure there is not a bacterial component to the signs.

In-depth Information on Treatment

Treatment for aseptic meningitis may include treatment with immunosuppressive drugs, most commonly s prednisone at a dose of at least 2 mg/kg twice a day. Medication is usually given orally unless your dog is too sick. In these cases, your veterinarian may start injectable medications. Treatment may be delayed until the results of the CSF tap are known.
Medications must be given long term – more than 4 weeks is typical. Medication is generally tapered gradually to alternate days over the course of treatment, which is usually several months. Response to treatment is typically seen within 24 to 48 hours of starting medications. Side effects from the medications include increased eating, drinking, urinating, and panting.
Relapses may occur during the tapering course. Relapses usually respond to increasing the medication dose and/or adding a second immunosuppressive drug.

Follow-up Care for Dogs with Aseptic Meningitis

If your dogs is showing signs of meningitis, you should contact your veterinarian immediately. If your veterinarian prescribes a medication, it is important to follow directions unless specifically told to change medication dosage or type.

Observe your pet closely for any worsening of clinical signs. If you notice any deterioration in your pet’s condition, especially during the tapering of medication, contact your veterinarian immediately.