Epilepsy in Dogs: New Therapies

Edward MacKillop DVM, DACVIM (Neurology), veterinary neurologist and neurosurgeon at Pittsburgh Veterinary Specialty & Emergency Center (PVSEC), discusses new therapies for dog epilepsy.

Interview Transcript (slightly modified for readability)

“Some of the new therapies that are out there would be drugs [such as] Keppra (levetiracetam), Zonegran (zonisamide), topiramate (Topamax), gapapentic, pregabalin (Lyrica), and then some pets are being given cannabinoids (or CBD). If we go back to the medications that I use most frequently, [I use] Keppra because it is a very effective medication for some patients, especially with myoclonic epilepsy. It tends to be very safe. It has both a standard release formulation and an extended release formulation (XR). The benefit of the XR formulation is patient compliance because it is a twice-a-day medication. The standard release medication typically has to be given three times a day for efficacy and so that is challenging for most pet owners. The value of the XR formulation is that we get better patient compliance, which means, hopefully, better epilepsy control.

Zonisamide (or Zonegran) is another medication I use regularly. I find it to be a very safe medication [and] it is very well-tolerated. It [also has] a low sedative profile.

Keppra has very few side effects, if any. Zonisamide does occasionally cause idiosyncratic reactions. The most common one that has been reported has been hepatopathy or disease of the liver, and it is typically an acute hepatopathy that occurs in the first two weeks of therapy. Beyond that, to my knowledge, there are no chronic side effects of zonisamide and for that reason I think it is a very good and effective medication. I still check labs, typically once a year, in a patient, looking for any long-term potential side effects. Whereas with Keppra, there is no drug monitoring necessary because the drug has no internal toxicities.”

The use of cannabinoids in managing epilepsy is really in the forefront right now in the human field. There is a good study that came out of Colorado [this year] looking at CBD for people with severe and refractory epilepsy and they found some efficacy for [CBD] for patients within that study. For the use in animals, it is still difficult because legislation does not permit the use of CBD in veterinary animals. Even in states that have medical cannabis laws, it is not extrapolated to animals.

There are states that have recreational cannabis usage, and in those states there is the possibility of using CBD to manage pets who have epilepsy. There is also the possibility of using CBDs that are extracted from industrial hemp, because that is, in fact, legal. There is some question as to the value or the quality of the CBD that is extracted from industrial hemp [however] and also a lot of the products may not contain what they report.”