Considerations regarding treating cats with seizures

Seizures are not uncommon in cats. Approximately 20% of the animals that I treat with seizures are cats. Unlike dogs, these patients do not have a high incidence of “idiopathic epilepsy”. In fact, several reports indicate that more than 75% of all cats presented with partial or generalized seizures have an underlying or systemic disease causing the seizures. For clinicians, the challenge is to identify causes such as ischemic encephalopathy, renal disease, hypertension, neoplasia, encephalitis, polycythemia, or other causes.

After the cat has been stabilized, and the seizures have been treated -if in status or having cluster seizures- a complete neurological examination should be performed. Abnormalities on the neurological examination suggest intracranial disease. The clinician should obtain a minimal database consisting of CBC, serum chemistry panel, thoracic radiographs, feline viral panel, T4 and urinalysis. Depending on these results, further infectious diseases can be investigated such as toxoplasmosis and Cryptococcus.  Other advanced diagnostics consisting of brain MRI or CT and cerebrospinal fluid analysis are indicated if the cause cannot be elucidated with the workup.

For treatment, I consider Phenobarbital to be the initial drug of choice to treat seizures in cats. Cats tend to tolerate Phenobarbital well - better than dogs in most cases. Dosing of 2-4 mg/kg twice a day usually results in an adequate serum drug concentration that manages most seizures in cats. My experience is that most cats respond very well to this protocol.

In cats that do not tolerate a higher dose of Phenobarbital or that seizure control is less than desired, the addition of either Keppra (levetiracetam) 15-20 mg/kg three times a day or (Zonegran) zonisamide 7.5-15 mg/kg twice a day may be an option.

Other drugs are being evaluated for seizure control in cats.

In general, I do not use benzodiazepines for daily anti-seizure therapy because tolerance can be a problem.  For example: cats developed hepatic necrosis on oral diazepam. This is a very serious and oftentimes fatal drug reaction.  It's not very common but it's serious enough that I still avoid using benzodiazepines, unless there are no alternative.

Potassium bromide in cats has been associated with coughing and dyspnea secondary to suspected pulmonary fibrosis. For this, I do not recommend this drug in cats.

If you have any questions regarding a cat with seizures, feel free to contact me regarding a consult.