Seizures and Idiopathic Epilepsy
Dr. Heidi Barnes DVM, DACVIM (Neurology)
Owner, Barnes Veterinary Specialty Services LLC
How are seizures diagnosed?
Seizures originate from the front part of the brain and result in synchronous, abnormal behavior. Often, but not always, your pet may have a change in their awareness, however this can be difficult to tell. Seizures occur from many causes. To definitively determine the cause of your pet’s seizures blood work, a brain MRI and a spinal tap are needed. Both the brain MRI and spinal tap require your pet to be put under anesthesia. Therefore, prior to anesthesia veterinarians require your pet to have full blood work and chest x-rays within 30 days of the MRI or spinal tap.
If all testing (blood work, MRI and spinal tap) are normal your pet will be diagnosed with idiopathic epilepsy. In this case the best course of action is to try to minimize the number and severity of seizures your pet experiences.
What is idiopathic epilepsy?
Idiopathic epilepsy, or “epilepsy” as some refer to this, is a disorder that is often genetic or inherited. Idiopathic epilepsy occurs when a neuron misfires in the brain due to an underlying imbalance in the neuron. That misfiring results in the neurons nearby to group their activity, thus resulting in what we see as a seizure. The root problem, however, is the misfiring neuron. Treatment is directed at minimizing the seizures that we see, not at eliminating this neuron from misfiring. This is a very important concept! Your dog or cat may continue to have occasional seizures throughout their life and this is okay, within some limits.
What is considered “good control” for an animal with idiopathic epilepsy?
Good control, as outlined by the International Veterinary Epilepsy Task Force in 2015, is 1 seizure or less every 3 months and each seizure less than 3 minutes long. To be clear, this means our goal is not zero seizures! (Although this is always nice when it happens.) Not all pets reach this goal and yet they can still have a good life.
What do I do if my pet has a seizure?
A single seizure, less than 3 minutes, should be recorded in a notebook or calendar specifically dedicated to your dog or cat’s seizure management. Record the date, time and approximate duration. If your pet’s seizures are becoming longer, closer together or more frequent please contact your veterinarian for assistance.
What do I do if my pet doesn’t have idiopathic epilepsy?
Idiopathic epilepsy is diagnosed when all other causes are “ruled out” or eliminated through the testing listed above. If the blood work, brain MRI or spinal tap identify an abnormality responsible for your dog or cat’s seizures they will be diagnosed with either secondary epilepsy (e.g. brain tumor, meningitis, encephalitis, hydrocephalus, head trauma, other) or metabolic seizures (e.g. low blood sugar induced seizures, kidney failure, liver failure, etc). See our other topic pages for a discussion on managing pets with secondary epilepsy and metabolic seizures.
What follow-up is needed for my pet with seizures?
If your pet is on anticonvulsant drugs you must maintain contact with a prescribing veterinarian annually. This allows your vet to maintain a client-patient relationship as outlined by the American Veterinary Medical Association, allowing them to prescribe drugs. Routine organ function testing (blood work) is strongly recommended at least once every 12 months. Some anticonvulsant drugs also need “levels” performed every 6-12 months for monitoring purposes.