Seizures in Cats

Summary

A seizure is an abrupt episode of uncontrollable muscle activity and is the physical manifestation of abnormal electrical discharges in the brain.  Seizures affect 2% of the feline population. While rare, they are among the most common neurological symptoms to affect cats. Seizures usually present as tremors, shaking, muscle spasms, and/or convulsions. 

Seizures, which may affect either the brain as a whole or just a portion thereof, can have varying underlying causes. The most common causes of seizures in cats are ingestion of toxins, head trauma, epilepsy, and brain tumor.      If a cat is having or has had a seizure, veterinary attention is warranted. The typical diagnostic work-up for a seizuring cat includes a physical examination, blood tests, and neurological examination to ascertain the root cause of the seizure and identify the correct treatment. 

Currently no vaccine can prevent seizures, but keeping the cat up-to-date with vaccinations provides protection against a number of diseases that may in turn cause seizures. 

Seizures may occur without a witness but leave evidence:

• Disrupted household objects

• Wet spots from drool or urine

• Feces smeared on fur or the floor

Treatment varies in accordance with the underlying cause of the episode and ranges from the elimination of the ingested toxin to life-long therapy with  anticonvulsant medications.

Guidelines

Seizures are one of the most common neurological emergencies in cats, but they're rare, affecting only 1-2% of the feline population.

Even though a seizure may be temporary and a one-time event, it has the potential to be an emergency. Seizures are to be expected and usually of no consequence for patients previously diagnosed with epilepsy, but epilepsy is rare in cats compared to dogs. In cats, seizures are much more likely to be indicative of an underlying brain disease or toxicity, so emergency care is indicated.

Seizures can be divided into two categories:

• Focal: focal seizures do not affect the entire brain and thus only a side or one specific part of the animal's body experiences the uncontrolled movement. Focal seizures can become generalized 

• Generalized: generalized seizures affect the entirety of the brain. They commonly result in loss of consciousness and sudden uncontrollable movement of the entire body, chomping, and urination/defecation.

Possible Causes

Seizures in cats can be divided into two types: intracranial and extracranial seizures.  Causes of intracranial seizures:   

• Brain tumor

• Brain inflammation 

• Brain parasites 

• Epilepsy

Causes of extracranial seizures:

• Toxicosis: ingestion of toxins may cause seizures 

• Hypoglycemia

• Metabolic diseases: malfunctioning of the kidneys, liver, and thyroid may affect the central nervous system

• Injury: trauma, especially to the head can cause neurological symptoms including seizures

Risk Factors

Non-emergency seizures are rare in cats. Emergency veterinary care is recommended for any cat experiencing a seizure, especially if it is the cat’s first seizure. If the cat’s initial seizure is brief (less than 3 minutes) and the cat rapidly returns to normal and remains that way, non-urgent veterinary care is another option. 

If it is not the cat’s first seizure, the relevance or emergency nature of the seizure varies depending on the cat’s diagnosis and progression of the underlying disease.  In summary, seizures are assumed to be an emergency until a veterinarian determines they are not. 

Emergency seizures are defined as:

• Status epilepticus: generalized seizures lasting more than 5 minutes; or three or more consecutive seizures without the animal regaining normal behavior between the seizures. 

• Any unexpected seizure where the underlying cause has not been identified, especially when the cat does not return to normal rapidly after the brief seizure stops. 

Multiple, recurring seizures can be divided into two categories:

• Primary: primary epilepsy usually has a genetic component and presents at a younger age (between the ages of 1 and 7). This is common in dogs as an inherited disorder, but is rare in cats.

• Acquired: acquired epilepsy is caused by external factors. These factors can either be strictly related to the brain, such as trauma, and cancer, or indirectly affect the brain such as metabolic disease, and hypoglycemia.

If the cat is experiencing an emergency seizure, call the veterinarian immediately. If the symptoms do not resemble status epilepticus, it is nonetheless advisable to contact the veterinarian, as the severity and scope of the event cannot be ascertained without a medical examination.

Testing and Diagnosis

A cat presenting with seizures typically undergoes the following diagnostics:

• Physical examination

• Blood test: to rule out infectious and metabolic causes and to asses the cat's general health

• Urinalysis to look for evidence of toxins

• Neurological exam

Once diseases outside of the brain are ruled out, the veterinarian may run further diagnostic tests such as X-ray, MRI (Magnetic Resonance Imaging), and CT (Computed Tomography) scan. 

Typical emergency care for seizures includes: 

• Fluid therapy 

• Short-acting anticonvulsant drugs 

• Nursing care and monitoring

Once the cat is stabilized, treatment depends on what has caused the seizure.  If the cause is toxicosis, the treatment may be limited to the elimination of the ingested toxin or may involve the treatment for liver and kidney damage. 

If the cat is subject to idiopathic, recurring seizures (epilepsy), long-term anticonvulsant therapy is usually prescribed. In this case, it is impossible to prevent the cat from having future seizures. The goal of therapy is to reduce the severity and frequency of the incidents. These medications do not cure the cat, and lifelong therapy is usually required.

If the cat is undergoing long-term therapy, it is important to be in close contact with the veterinarian for ongoing monitoring of anticonvulsant levels and to determine the best dosage and treatment schedule.

Similar symptoms

Tremors, narcolepsy, and vertigo may be mistaken for seizures.

Associated Symptoms

Cats suffering from seizures may present several additional symptoms, including but not limited to:

• Loss of consciousness 

• Vomiting

• Drooling

• Urinary incontinence 

• Fecal incontinence