Overview of Feline Meningitis (Brain Tissue Inflammation)

Meningitis

Definition

Meningitis is a condition that occurs in cats when one or more of the three tissue layers that surround and protect the brain and spinal cord, known as the “meninges,” become inflamed and/or infected.

How Meningitis Affects Cats

Meningitis is not a disease. It is a very serious and painful pathological condition of inflammation of delicate tissues surrounding the brain. This typically leads to inflammation of the brain and/or spinal cord, causing direct neurological deficits. It is more common in companion dogs than in domestic cats. However, cats of any age, breed or gender can be equally affected, although newborns and immunocompromised animals are especially at risk. Affected animals are almost always systemically ill. They develop a high fever, a stiff neck and awkward gait, painful muscle spasms in the back, limb rigidity and extreme sensitivity to touch and temperature. They progressively become lethargic, anorexic and nauseous and frequently vomit. Advanced meningitis can cause profound depression, blindness, progressive paralysis, seizures, confusion, agitation, incoordination (ataxia) and/or aggression.

Causes of Feline Meningitis

Meningitis can be caused by anything that triggers the inflammatory cascade in the tissues of the meninges. This can be viral, protozoal, bacterial, fungal, rickettsial or parasitic. Chemical toxins (lead, arsenic, etc.) have been implicated as well. Even metastatic cancer cells reportedly can cause or contribute to meningitis. Viral feline infectious peritonitis infections and blood parasites spread through ticks, such as Rocky Mountain spotted fever and ehrlichiosis, may also cause feline meningitis. Meningitis is an extremely serious condition that can be fatal.

Symptoms of Feline Meningitis

Meningitis is not a disease but rather is the condition of inflammation of the meninges – the three membranes that intimately surround and protect the brain and spinal cord. Meningitis is very serious; if your cat is exhibiting any of the clinical signs of this disorder, it is important that you visit with your veterinarian immediately. Early diagnosis and treatment can improve the chances of a positive result, depending upon why the meningitis occurred.

Symptoms of meningitis include fever, neck and limb stiffness, painful spasms of the back muscles and extreme sensitivity to touch. A high fever can contribute to inappetence and lethargy. Affected cats’ gait often becomes awkward, and their legs seem to refuse to bend normally. The neck stiffness in cats with meningitis can be so extreme that the head tilts to the side and the chin is turned towards the back. When someone touches the cat, its skin may twitch, the cat may become aggressive or it may yelp in pain. Cats with advanced meningitis usually become severely depressed, blind and progressively paralyzed. Seizures, confusion, agitation and aggression are not uncommon. Advanced meningitis can also cause a condition called ataxia, in which the cat cannot coordinate its muscle movements. The cat may begin to circle, stumble or walk with its legs spread abnormally far apart.

Diagnosing Meningitis

Many cases of meningitis are diagnosed by sampling and culturing the cerebrospinal fluid to identify causative organisms. Blood and urine tests are usually performed as well to rule out systemic causes of the cat’s clinical signs. If these results are negative, the veterinarian may prescribe a course of drug therapy symptomatically; if this treatment is successful, a diagnosis of meningitis will be presumed. In some cases, the veterinarian, or client, wishes to have a conclusive meningitis diagnosis before any medical treatment is begun. At this stage, the only realistic tests for a definitive diagnosis of meningitis are a spinal tap, an MRI and/or a CT scan. These tests are expensive, and they are not widely available especially in rural areas.

Meningitis is potentially life-threatening. Early diagnosis is essential for proper treatment and recovery.

Treating Meningitis in Cats

Meningitis in cats is often difficult to diagnose and even more difficult to treat. Some veterinarians may start a treatment program with corticosteroid medications even before a diagnosis is confirmed, to calm the effects of central nervous system inflammation that often are virally-induced. Aggressive inpatient treatment is often necessary. Bacterial meningitis, when it does occur, requires strong antibiotic medications that can cross the blood-brain barrier, given at high doses and for long periods of time.

Supportive nursing care is also important to manage the dangerous side effects that meningitis can cause in cats. Anti-seizure medications, anticonvulsants, intravenous fluid therapy, nutritional supplementation and pain medications are normally needed in advanced cases of meningitis. It can take months for a cat to recover from meningitis, and often these treatments and supportive care will need to be administered for weeks to months.

If your cat is diagnosed with meningitis, you will want to have a frank discussion with your veterinarian about realistic treatment options and how well your pet may respond to those options.

Special Notes

Meningitis can be difficult to diagnose and to treat. Meningitis is often diagnosed through spinal fluid taps, although sampling the cerebrospinal fluid in affected animals is contraindicated if there are signs suggestive of high intracranial pressure. Blood tests and blood cultures may also be useful to eliminate underlying systemic causes of the clinical signs. The long-term prognosis for cats with meningitis is generally guarded to poor. Part of the difficulty with diagnosing and treating meningitis in cats is that it the condition is so often caused by another serious underlying condition which must be independently addressed. The “general” meningitis treatment protocol is to use immunosuppressive drugs, such as steroids, and broad-spectrum antibiotics that will penetrate the blood-brain barrier to reduce the effects of swelling and eliminate any contributing bacterial infection. Unfortunately, these treatments are often of little help to affected cats.

Disorders Similar to Meningitis