Epilepsy in Cats

What Is Epilepsy in Cats?

Epilepsy is a neurologic medical condition that is defined by a cat having two or more unprovoked seizures. If your cat has only had one seizure, it is considered an isolated incident and they are not considered to have epilepsy.

Types of Epilepsy in Cats

Seizures in cats come from an abnormal electrical activity in the brain.

Idiopathic epilepsy is a hereditary disorder of the brain that occurs for an unknown reason. Idiopathic, or primary, epilepsy is the diagnosis made in cats when there is no structural cause for the seizures but there is abnormal electrical activity.

Symptomatic epilepsy involves seizures where structural changes to the brain are seen on advanced imaging, such as an MRI. Idiopathic epilepsy is common in dogs and is rare in cats, but is certainly a possible diagnosis if your cat develops seizures. While still rare, cats are more likely to have structural changes, therefore most epilepsy in cats is classified as symptomatic.

Depending on the underlying cause of epilepsy in cats, seizures can start at anytime in life, young or old. No matter if your cat has had one or many seizures, contact your veterinarian for guidance, as your cat will likely need an examination.

What is the Difference Between a Seizure and Epilepsy in Cats?

Seizures in cats are caused by a sudden surge in electrical activity of the brain that causes symptoms such as tremors and convulsing. Epilepsy is the term used to describe a neurologic medical condition in which a cat has repeated seizures—two or more.

Epilepsy can be characterized by having one seizure at a time or multiple clusters, and they can occur regularly or unexpectedly. It is often a symptom of a disease process within the brain, but in cats, seizures are often from an unknown cause.

Symptoms of Epilepsy in Cats

Epilepsy is associated with three stages when a cat is having a seizure. The symptoms of each stage can be very different.

Pre-ictal phase—aura; characterized by a behavior change before seizure occurs:

• Hiding

• Attention-seeking

• Licking lips

• Head turning unusually

Ictal phase—active seizure activity

Generalized seizure also called gran mal seizure (similar to a human’s gran mal seizure) and often lasts one to two minutes. It affects the entire body and usually causes cats to be unaware of their surroundings or even lose consciousness:

• Partial or complete collapse

• Jerky movements

• Convulsing

• Stiff limbs with joints locked

• Paddling or running movements of the legs and arms

• Urination and/or defecation

• Excessive salivation or foaming at the mouth

• Disorientation

• Often, but not always, the head is tilted backward

• Status epilepticus in particular is a type of generalized seizure that lasts more than 5–10 minutes. This is a true medical emergency and requires emergency treatment

Partial or focal seizure­—Abnormal movement localized in one area of the body; cat is often fully awake and aware of its surroundings:

• Strange, uncharacteristic behavior

• Unusual vocalization

• Drooling

• Twitching

• Abnormal body posture

• Chewing movements

 Post-ictal—change in behavior after seizure occurs; period of time before cat acts “normal” again:

• Disorientation

• Pacing

• Lethargic

• Not wanting to eat

Causes of Epilepsy in Cats

Epilepsy is more common in cats younger than 8 years old, but it can happen at any age. Any disease that involves the brain directly or affects other body systems, such as the liver or kidneys, can cause seizures.

Intracranial causes of seizures come from within the brain itself, while extracranial causes are outside of the brain. Seizures in cats can occur at any time, but they often occur when there are changes to brain activity such as falling asleep, waking up, excitement, feeding time, or another change in activity.

Idiopathic or primary epilepsy

• Unknown cause—no structural change in the brain—only a change in function of brain activity. It is seen primarily in cats that are considered young adults (between 1-6 years of age)

Intracranial epilepsy

• Brain tumors

• Inflammation of the brain (meningitis)

• Head trauma such as traffic accidents, skull fractures, cat bites

• Brain parasites such as toxoplasmosis

• Brain infection such as encephalitis

• Brain anomalies such as hydrocephalus

Extracranial epilepsy

• Inner or middle ear infections

• Toxin exposure (may cause epilepsy but often only causes one seizure)

  • Exposure to flea and tick medications formulated for dogs

  • Ingestion of human medications, ethylene glycol (antifreeze), or rat poison

• FIP and FeLV

• Metabolic anomalies such as portosystemic shunt (PSS), low blood calcium (hypocalcemia), low blood sodium (hyponatremia), low blood sugar (hypoglycemia), or thiamine deficiency

• Diabetes

• Liver or kidney disease

• High blood pressure

How Veterinarians Diagnose Epilepsy in Cats

A diagnosis of epilepsy is made when your cat has two or more seizure episodes. While the actual act of having a seizure can be diagnosed visibly, the underlying cause requires diagnostics testing. If you suspect your cat is having a seizure, one of the most helpful tools for your veterinarian is taking a video of the behavior.

Full bloodwork and urine testing is needed to evaluate your cat’s blood sugar, along with bone marrow, liver, and kidney function. Specialized blood tests for infectious diseases such as FIV, FeLV and toxoplasmosis are often done as well. X-rays are taken to look at the structure of the skull and other internal organs, but the most common tests done on cats with a suspected epilepsy diagnosis are CT scans or MRIs. These imaging techniques are usually done with a veterinary internal medicine specialist or a veterinary neurologist. which your primary veterinarian can refer you to after epilepsy is diagnosed. While your cat is under anesthesia for a CT scan or MRI, your veterinarian will often take samples of spinal fluid for infectious disease testing and look for signs of inflammation. Intracranial causes of epilepsy do require a CT or MRI to be confirmed.

The goal of the diagnostic testing is to find the underlying condition, so that a specific treatment plan can be made for your cat to help reduce or eliminate further seizures from occurring.

Depending on the severity of your cat’s epilepsy, your veterinarian will determine how aggressively they will need to search for a definitive diagnosis.

Treatment of Epilepsy in Cats

While a single seizure episode may be curable, epilepsy is often about managing the disease, unless the cause of the seizure is found and eliminated.

Treating epilepsy can often be very complicated, involving multiple medications or only one, as each cat responds differently to treatment.

Diabetes, high blood pressure, kidney disease, liver disease, and cancer must be treated to try to avoid additional seizures. Anti-convulsant medications are the foundation of epilepsy treatment in cats.

Common anti-convulsant medications for cats include phenobarbital, potassium bromide, levetiracetam (Keppra), and zonisamide. Most medications, especially if they work well to control the seizures, are lifelong. Cats with severe illness associated with their epilepsy will often have to be hospitalized on IV fluids and started on injectable anti-convulsant medications. Depending upon your  cat’s diagnosis, a special diet may be required, although cats can typically remain on their normal diet.

Recovery and Management of Epilepsy in Cats

Cats with epilepsy and on anti-convulsant medications are monitored closely with consistent, routine blood testing to check for therapeutic blood levels. Some of the medications, especially phenobarbital, can have toxic effects on your cat at certain levels, so frequent monitoring of the blood levels is very important.

Monitoring also lets your vet know if the levels are too low and your cat is having more frequent seizures, so the dose of the medication can be increased. It also indicates if an additional medication is needed to help control the seizures.

Always give all medications as prescribed by your veterinarian. Even if you think a medication is not helping your cat, do not stop giving it without your veterinarian’s approval, as this can be just as dangerous as the seizures itself. Without medication, sudden withdrawal can lead to uncontrollable seizures. It is also very important to stick to the dosing schedule for seizure medications.  

In cats with epilepsy, the goal is to maintain a good quality of life. The seizures will not completely go away, but will hopefully be reduced in frequency and severity. Even if your cat still has occasional seizures, they can live a long, healthy life, depending on the underlying cause of the epilepsy.

Featured Image: iStock.com/Ivan-balvan