Seizures in Cats: Causes and Treatments

A seizure is a sudden and uncontrolled burst of activity that may include one or more of the following signs: champing and chewing, foaming at the mouth, collapse, jerking of the legs, and loss of urine and stool. An altered level of consciousness is followed by a gradual return to normal.

Some seizures are atypical. Instead of the classic convulsion, the cat exhibits strange and inappropriate behavior, such as sudden rage or hysteria. Cats may lick and chew themselves, scratch or bite their owner or another cat. This is called a psychomotor seizure.

Most classic seizures in cats are caused by acute poisoning. Seizures after head injury may occur at the time of the accident, but in most cases appear several weeks later as a result of scar tissue on the brain. Stroke, metabolic disorders, and epilepsy are other causes of seizures.

Common poisonings that induce seizures include strychnine, antifreeze (ethylene glycol), lead, insecticides (chlorinated hydrocarbons, organophosphates), and rat poisons. Organophosphates characteristically produce seizures that are preceded by drooling and muscle twitching. A history of exposure to an insecticide (spray, dip, or premise treatment) suggests this diagnosis.

Kidney and liver failure, accompanied by the accumulation of toxins in the blood, can cause seizures and coma.

Epilepsy is a recurrent seizure disorder that originates in the brain. It can be caused by outside influences, such as trauma, which is acquired epilepsy, or from a defect in neurochemicals in the brain, which is idiopathic epilepsy. Idiopathic epilepsy always has symmetrical signs. It is far less common in cats than it is in dogs.

To establish a diagnosis of epilepsy, the attacks must be recurrent and similar. Toward this purpose your veterinarian will ask you to provide a complete description of your cat's behavior before, during, and after the seizures.

Narcolepsy-cataplexy is a rare condition in which the cat suddenly falls asleep and drops to the ground. The cat may have one or dozens of such attacks in a day, lasting a few seconds or up to 20 minutes. The attacks can be reversed by petting the cat or making a loud noise. The cat is completely normal when awake.

There are a number of conditions that, while not true seizures, can easily be mistaken for them. Bee stings, for example, can cause shock and collapse. Fainting spells associated with advanced heart or lung disease may look like seizures.

A cat who has suffered from a seizure should have a complete veterinary workup, including blood chemistries, a neurological exam, and, if available, an MRI or CT scan.

Treatment: If your cat is having a classic seizure, cover the cat with a blanket and stand aside until the animal quiets down. Do not put your fingers in the cat's mouth or try to wedge something between the teeth. Cats cannot swallow their tongues while having a seizure, and this will simply result in you being badly bitten. Then take your cat to the veterinarian so they can determine the cause of the seizure.

Seizures lasting over five minutes (continuous seizures or status epilepticus) are very dangerous. They must be stopped to prevent permanent brain damage. Valium is given by your veterinarian to stop a continuous seizure.

Recurrent seizure disorders can often be controlled with medications. Although there is no cure for idiopathic epilepsy, seizures can generally be controlled medically. For acquired epilepsy or seizures of other causes, the inciting cause must be treated.

The same drugs used in treating seizures in people and dogs, such as potassium bromide, phenobarbital, and diazepam (Valium) may be tried for treating a cat with seizures. However, in cats, all of these medications can be quite toxic and require close veterinary supervision. Potassium bromide has been connected to respiratory problems in about 35 percent of the cats who have taken it. Blood tests should be done periodically to guard against toxic effects. Families should keep track of any seizure activity on a calendar so they can look for any pattern to the seizures.

With a comatose cat, the most important thing to observe is the level of consciousness. This cat cannot be aroused.

This article is excerpted from “ Cat Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.