Epilepsy

There are few things with pets that make a person feel more helpless than watching a dog convulsing uncontrollably with seizures. And, even though there are medications that can help, many times they aren’t 100% effective. When the cause of the seizures cannot be found, in spite of aggressive diagnostics, we call this type of seizure disorder: “Epilepsy”

These “anti-convulsant” drugs, such as phenobarbital, Keppra™ (levacetiram), Neurontin™ (gabapentin) and potassium bromide, may cause an epileptic dog to become drowsy all of the time, so much so that their guardians feel they’ve lost their quality of life, and may make the very difficult decision to put them to sleep as a result of these side effects.

When an epileptic dog is medicated and still has seizures, we call them: “Breakthrough Seizures”, and we call epilepsy with breakthrough seizures as “Refractory Epilepsy”.

If your dog has these breakthrough seizures, it might be because their medication dosage needs to be adjusted. So the first thing you should do is call your vet and set up an appointment for a blood test to evaluate blood levels of these drugs. Possibly with dosage adjustment the breakthrough seizures will cease.

Your veterinarian’s office will explain to you, depending upon which medication(s) your dog is on, when they will need to draw blood for this test. This way they can evaluate the peak blood levels or the lowest blood levels of the medication, and make adjustments if indicated.

The healthy brain functions with regular patterns of electrical activity, which are the result of the nerve cells in the brain “firing” (sending electrical signals down their fibers) in a coordinated and systematic fashion. For different reasons, when those signals start firing in an irregular and uncoordinated fashion, seizures result.

Depending upon which part of the brain has those nerve fibers inappropriately firing, you will see different types of convulsive activity.

The first phase is called the “pre-ictal phase”, which is the period of time just before the seizure occurs. Some pet guardians say they can tell that their pet is going to have a seizure from their behavior. They may start staring into space, or licking their lips, or even vocalizing. People report that there may be a visual “aura” that they see, or they smell something. There are canine companions for people who have epilepsy who can actually tell their human is going to have a seizure by their smell, and they alert the epileptic to that fact, so they can stop driving, or put themselves into a protected place before they lose control.

The second phase of the seizure is the actual seizure itself. Typically, in the dog, seizures last only a minute or two, but to the person observing the seizure it can seem like a lifetime. We get concerned about seizures when they continue longer than 5 minutes, and if they don’t stop at all, they can be life threatening and your dog needs to see a veterinarian or you should take your dog to the animal ER to be given strong medication to stop this continuous seizure. A continuous seizure is called medically: “Status epilepticus”.

Some dogs when they finish their seizure, will have another one in a few minutes, and then possibly another one and another. These types of seizures are called “Cluster Seizures” and indicate a more severe type of seizure than a single seizure, but not as severe as status epilepticus, as long as the cluster seizures stop after a while.

Once the seizure has run its course, the dog will then enter its “post-ictal phase”. During this period of time your dog may appear disoriented, or may seem blind because its bumping into things. The length of the post-ictal phase can be variable, but longer post-ictal phases seem to be associated with more severe seizures. The post-ictal phase is always present with epilepsy, and helps to differentiate it from other events that look similar, like fainting, or spastic muscle contractions.

I have been describing the most severe type of seizure which is called the “Generalized” or “Grand Mal” seizure. This is the most common form of seizure in our pets. In this type of seizure the entire body is involved, and may become stiff, or alternate between rigidly held legs and legs that are flexed tightly. The seizuring pet will become unresponsive to verbal commands, and may lose control of its urine or bowel. Not uncommonly they will vocalize, and sometimes look like they are running, while actually laying on their side. They may arch their back, and turn their head around to look backwards during the seizure.

It is important that the seizuring animal be placed in an area where they can’t fall down stairs or otherwise hurt themselves. There is no need to worry about them swallowing their tongues, which is a common fallacy and doesn’t happen with our pets. You may get bitten by them if you try to grab their tongue while they are in the middle of a seizure. Don’t let yourself get hurt, any more than letting your pet get hurt.

Another type of seizure is called a “Partial seizure”. This seizure originates in a small local area of the brain, and causes seizure activity in only one local area of the body. Sometimes these partial seizures will become, over time, more generalized, depending upon the initiating cause of the seizure.

The third type of seizure is called the “Psychomotor seizure”, and in this type of seizure the pet’s behavior is affected. It may manifest as howling, snapping, circling or other sorts of unusual behavior for that animal.

Known causes for epilepsy include brain cancer, head trauma, infection, severe hypoglycemia (low blood sugar) hypothyroidism, toxins from faulty metabolism (e.g.: some dogs or cats with end-stage kidney disease will have seizures), or environmental poisons.

Diagnostic tests initially are simple blood tests and an eye exam to check the retina of the eye. (Did you know that when we are looking at the retina, we are actually looking at a part of the brain?) If those tests are negative, then, depending on the age of your dog, a spinal tap might be performed to determine of there is an infection present, or, with an older animal which is more likely to have brain cancer, it may be necessary to have an MRI or CT scan of your dogs brain for a diagnosis.

In young pets, less than a year old, we normally suspect infection. In pets less than 5 years of age, and no cause can be found with blood tests, we call this type of seizure disorder, “Idiopathic epilepsy” or just simply, “Epilepsy”, which means there is no known cause of the seizures. In the older pet, although “Adult Onset Epilepsy” may also be without a cause similar to the idiopathic epilepsy of younger dogs, there is a strong suspicion in these older animals that brain cancer may be present.

Certain breeds of dogs have a greater likelihood of developing idiopathic epilepsy: Schnauzers, Basset hounds, Collies and Cocker Spaniels have a 200-300% greater chance of having this chronic debilitating disease. Other breeds of dogs are known to be more likely to have refractory seizures. These are the German Shepherds, Golden Retrievers, Irish Setters and Saint Bernards.

Treatment depends upon the cause of the seizures, if it can be found. If there is an infection or a tumor that is causing the seizures, then, if possible, that needs to be treated directly. At the same time, seizure control medication is given to suppress the seizures. In some pets, seizures may only occur once every few months. For these, it may not be a good idea to use strong seizure medication to affect such a rare event. The potential risks of using the seizure medication out-weigh the minimal benefits of controlling seizures so far apart in occurrences. But, when the seizures become more frequent, then the risk of the medication to the benefit of controlling the seizures becomes more acceptable, and that’s when we start the medication to control the seizures.

In addition to seizure medication, there are nutritional supplements and herbal formulas that can help control the seizures, and reduce their severity. Supplements such as high doses of fish oil, the amino acid l-taurine, and the phospholipid found in lecithin, phosphatidylcholine, can be very helpful. Acupuncture can also help, as can chiropractic, sometimes, if the neck is out of alignment. There are a number of Chinese herbal formulas specifically designed to address seizures, and they work best if the formula is matched to the individual patient’s type of seizure.

Recently it has been known that the non-psychotropic derivative of marijuana or hemp, known as cannabidiol (CBD) can also help control seizures in children, especially with seizures refractory to anticonvulsant medications. Anecdotally similar results are being reported in dogs. Unfortunately, the research studies to verify that CBDs can help dogs with epilepsy and/or refractory seizures has not yet been completed.

Because seizures can be so debilitating and life threatening, it is important to consult with your veterinarian or a holistic veterinarian to help you. This website can also be a good resource for you, and we welcome your questions. Please do not take your pet off anti-convulsant medication without first consulting with your veterinarian, as this could be very dangerous to them.

Future columns under this Canine Epilepsy thread and under the Cannabis thread will discuss these alternative options in great detail, as well as ways to reduce the negative side-effects such as elevated liver enzymes from anti-convulsant medications. If you have a dog with epilepsy, we want to help.