Meningitis, Meningoencephalitis, Meningomyelitis in Cats

By PetMD Editorial on Feb. 14, 2010

Bacterial Meningitis and other Nervous System Infections in Cats

The system of membranes which envelops the cat's central nervous system is called the meninges. If this system becomes inflamed, it is referred to as meningitis. Meningoencephalitis, meanwhile, is the inflammation of the meninges and brain, and meningomyelitis is the inflammation of the meninges and spinal cord.

Inflammation of meninges commonly leads to secondary inflammation of the brain and/or spinal cord, resulting in various neurological complications. Long-term inflammation can also obstruct the flow of cerebrospinal fluid (CSF) -- the protective and nourishing fluid that circulates around the brain and spinal cord -- which leads to accumulation of CSF in the brain and thus severe complications such as seizures and paresis.

Symptoms and Types

Neurological symptoms often associated with meningitis, meningoencephalitis, and meningomyelitis such as impaired movement, altered mental state, and seizures, may be profound and progressive. Other symptoms generally seen in cats suffering from one of these conditions include:

Depression
Shock
Low blood pressure
Fever
Vomiting
Abnormal increase in sensitivity to various stimuli (hyperesthesia)

Causes

The most common cause of meningitis is a bacterial infection in the brain and/or spinal cord originating from elsewhere in the body. Meningoencephalitis, meanwhile, is usually due to infections of the ears, eyes, or nasal cavity. And meningomyelitis generally proceeds following diskospondylitis and osteomyelitis. In kittens and cats with compromised immune system, such infections are commonly reach the brain and spinal cord via the blood.

Diagnosis

You will need to give a thorough history of your cat’s health, including the onset and nature of the symptoms. The veterinarian will then conduct a complete physical examination and several laboratory tests -- such as complete blood count (CBC), blood culture biochemistry profile, and urinalysis -- to help identify and isolate the type of infection.

Biochemistry profile, for example, may indicate liver and kidney involvement, while blood testing may reveal an increased number of white blood cells, which is evidence of an ongoing infection. Urinalysis may also reveal pus and bacteria in the cat's urine, an indication of urinary tract infections.

Other tools often used to identify the infectious agent involved include magnetic resonance imaging (MRI), abdominal ultrasounds, thoracic and abdominal X-rays, and samples from the skin, eyes, nasal discharge, and sputum.

One of the most important diagnostic tests, however, is CSF (or cerebrospinal fluid) analysis. A sample of your cat's CSF will be collected and sent to a laboratory for culturing and further evaluation.

Treatment

In severe cases of meningitis, meningoencephalitis, or meningomyelitis, the cat will be hospitalized to prevent more severe complications. Once the causative organism is identified, your veterinarian will employ antibiotics intravenously to maximize their effectiveness. Antiepileptic drugs and corticosteroids may also be prescribed to control seizures and reduce inflammation, respectively. Cats that are severely dehydrated, meanwhile, will undergo immediate fluid therapy.

Living and Management

Rapid and aggressive treatment is vital for a successful outcome, although its effectiveness is highly variable and overall prognosis is not favorable. Unfortunately, many cats die from these type of infections once it reaches the central nervous system, despite treatment.

However, if treatment is successful it may take more than four weeks for all the symptoms to subside. The cat's activity should be restricted during this time and until it is stabilized.