Epilepsy In Your Pet
Seizures In Dogs And Cats
Read About Pexion
Or Learn About NeuroCare™
Ron Hines DVM PhD
Lots of my articles are plagiarized and altered on the web to market products and services. There are never ads running or anything for sale with my real articles. Try to stay with the ones that begin with http://www.2ndchance.info/ in the URL box or find all my articles at ACC.htm.
Never use supermarket "flea-drops" (permethrin products, spot-on) on cats. Even exposure of your cat to canine pets in the same household that have those products applied to them has been enough to cause severe seizures in felines. Read about the problem here
Epilepsy is a disease in which your pet is subject to recurrent seizures or convulsions. It is quite similar to the epilepsy that occurs in people. Seizures in our pets can have a number of causes - Not all seizures or convulsions are due to common epilepsy (less than half are).
Idiopathic means that we do not know the cause. Once we have eliminated all other possible causes, we are left with a diagnosis of common (=simple, true or idiopathic) epilepsy.
Veterinarians find no physical or chemical problems in pets that have idiopathic epilepsy when they are not experiencing a seizure. All the blood tests, all the x-rays and all the examinations come back normal. But medical diagnostic equipment is becoming more an more sophisticated as time goes by. So it is only a matter of time until we will be able to see what the physical problem actually is in your pet. (ref1, ref2)
What Pets Get Epilepsy ?
Any breed of dog or cat can develop epilepsy. But golden retrievers, beagles, cocker spaniels, dachshunds, German shepherds, Irish setters, schnauzers, and huskies seem to have more than their fair share of epileptic problems. Seizures also occur more frequently in staffordshire bull terriers ; but those seizures are usually related to a specific neuro-metabolic disorder seen in this breed. (ref)
In cats, the common (idiopathic) form of epilepsy is seen most frequently in Persian and Siamese cats.
Epilepsy is known to effect specific dog and cat blood-lines within a breed more frequently than others. So veterinarians believe that idiopathic epilepsy (the kind that is usually relatively stable from month to month and year to year) is most often a genetically transmitted, inherited disease. (ref). Usually, a parent or a close relative of your pet also had epilepsy. In young adult dogs, the majority of epilepsy is that non-progressive, idiopathic, form. The causes in cats are less clear - probably because it is a less common problem in cats and so, less studied.
It is easy to get confused regarding seizures. All epileptic pets have seizures; but not all pets that have had seizure(s) have epilepsy.
In cats that experience seizures, only about a third of the cases are the non-progressive, idiopathic form. In cats, brain inflammations (encephalitis), exposure to toxic substances, flea and tick control products, traumatic brain injuries, abnormal body metabolism, brain tumors and FIP account for the other two-thirds. Your cat is more likely to be among the fortunate third if it is less than 3.5 years of age when the problem first begins and is also negative for Feline AIDS, Feline leukemia , and the mutated FIP coronavirus.
What Is Happening When My Pet Has A Seizure ?
It is very frightening to watch a pet experience a seizure. But try to keep in mind that during that frightening experience your pet is not in pain. Your pet may vocalize, thrash around, or void its bladder and intestines, but it does not experience painful sensations. It is just before and just after a seizure that your pet will be frightened, confused and need your reassurance most.
During an epileptic seizure random electrical impulses are sent from the nerve cells of your pet's brain to muscles throughout its body. In idiopathic epilepsy, the source of these abnormal brain impulses are small areas of abnormal or damaged brain tissue. Although during a complete epileptic seizure the pet looses consciousness and has no memory of the event ever occurring, there are instances in some dogs and cats where the seizure is partial and the pet is at least somewhat aware of you and things that are occuring in its environment. Their judgement and behavior in those situations is flawed so they require your caution.
Physicains and veterinarians attempt to subdivide seizure types by the signs that occur and the areas of the brain that they believe are involved. However, there is considerable overlap, the terms are imprecise and a lot of disagreement exits. But here is what I was taught in school: Seizures that put the whole body into severe muscle contractions, are called grand mal seizures. Seizures that are less severe, only affect a few muscle groups or are no more than a brief fainting experience are sometimes called petit mal or absence seizures. Status epilepticus and cluster seizures are terms used for severe seizures that occur again and again with little or no rest between convulsions. Status epilepticus is exhaustive and can be fatal.
During a seizure, tiny areas of the pet's brain begin sending out electrical impulses that are received by the nerve cells that surround them. This results in a chain reaction (a "storm") in which the surrounding nerve cells are stimulated to fire off a shower of signals of their own to various muscles of the body. In this respect, a typical epileptic seizure is much like a single snowball setting of a great avalanche. If the seizure affects the whole body, the pet looses consciousness. If it is a partial seizure, the pet may realize that something is occurring.
Secondary Epilepsy and Seizures :
When a defect within the brain can be identified as the source of the abnormal impulses, many vets call the condition symptomatic or secondary epilepsy. Secondary seizures often occur when pressure within the brain is too high (intracranial pressure). They can also occur when the brain is inflamed or when a brain tumor is present. The same drugs used for idiopathic epilepsy may control the seizures for a while ; but unless the underlying cause is determined and successfully treated, the pet' long term outlook is grave.
Things outside the brain can cause secondary epilepsy too. Things like overheating (hyperthermia), low blood glucose (hypoglycemia), intestinal inflammation or liver or kidney failure (that's the reason your vet has to run all those expensive tests). Poisons and toxic chemicals can also cause seizures. For example, certain flame retardant chemicals, when eaten, have the ability to cause seizures. (ref). On occasion, Thiamine-deficient diets have also been known to caused seizures in cats. (ref) Pets accidentally eating xylitol - containing products can also result in seizures because they cause such a sudden drop in blood sugar. (ref)
More On Epilepsy In Cats :
Idiopathic epilepsy is much less common in cats than in dogs. As I mentioned earlier, unlike dogs, cats more often develop seizures because of some progressive, acquired brain disease. Because many of these underlying causes increase in severity over time, the long-term prognosis (outlook) for epileptic cats is not nearly as good as it is for dogs. But even in these cats, your veterinarian can often control the seizures for a time.
I have seen more idiopathic or common epilepsy in pure-bred than in randomly-bred housecats.
A common cause of epileptiform (epileptic-like) seizures in cats is infection with the virus of feline infectious peritonitis ("the dry form" of FIP). A rarer cause is infection with toxoplasmosis. Other underlying causes are increased pressure within the pet's brain (hydrocephalus), liver or kidney disease, low blood sugar, brain tumors, vitamin B-1 deficiency, feline immunodeficiency virus (feline AIDS), rabies, insecticides, antifreeze and migrating parasites (like baylisascaris ). They account for almost all of the other cases of seizures in cats.
When In Life Does Epilepsy Usually Start And What Does A Real Seizure Look Like ?
Most pets have their first epilepsy seizures between 1 and 5 five years of age. During a complete seizure, the pet falls on its side with its legs outstretched and it’s back arched. Partial seizures have much more variable signs. Most pets maintain their legs rigidly extended but some paddle as if they were running. Pets may whine - although they are not in pain.
These pets often void their bowels and bladder during their convulsions. Their jaws are clenched during the first phase of the seizure. If only a portion of the body is affected by the seizure the pet can remain consciousness - but its reasoning abilities and mentation are generally flawed until a few minutes after seizure has passed.
Some forms of focal seizures or partial epilepsy are misinterpreted by owners as just a periodic quirky behavior. Sometimes muscles of the face just go into a jerky motion. Sometimes the pets appear to be snapping at invisible flies or chewing gum or running round and round in circles.
Frontal Lobe Epilepsy
Some seizures affect portions of the pet's brain that control thought rather than motion. When an area of the brain that controls the conscious thought process is affected the seizure is called a psychomotor seizure or hallucination. In humans this form of seizure is called frontal lobe epilepsy. During this altered period of consciousness your pet may show fear, aggression, hyperactivity, or repetitive nonsensical behavior. Some pets hear imaginary noises. Your pet may bite or snap at you if you disturb it during one of those episodes. Now and then, dog owners tell me that their pet had a "bad dream" - perhaps that was all it was - perhaps there was more to it than that.
Because so many areas of the brain can give rise to epileptic seizures, no two pets exhibit exactly the same signs. In some instances seizures will be a one-time episode never to occur again. In other pets the problem reoccurs at regular intervals of from every several days to several times a year. Common medications to treat epilepsy can damage your pet's liver over time. Only you, not your veterinarian, can decide if the number and severity of seizures your pet experiences, justify the risks of continuous, lifetime medication.
Stages Of A Seizure
An epileptic seizure event can be broken down into three distinct stages. It is an ancient disease - written about since writing was invented - so the event has been divided in many ways using many confusing terms with considerable disagreements and overlap. Various comissions, boards, study groups, etc. feel compelled to change the terms and classifications at regular intervals - at just about the time that physicians, veterinarians and the public become comfortable with the terms that are in us.
The first stage is often called the prodromal, or warning stage. This stage usually lasts several minutes but can last much longer. During this stage, the pet may have changes in its mood and behavior and may appear anxious. Some common signs are restlessness, wandering, pacing, licking, trembling and vomiting. In epileptic people, therapy dogs have been trained to warn their owners during this stage that a seizure in their owner is eminent.
next stage of an epileptic seizure was once called the ictus or ictical stage. This is
the time of the seizure itself when the body is subject to uncontrolled
movement and thrashing due to the electrical "storm" in its brain. During this stage, the pet is unconscious.
Paddling or swimming movements, clenched teeth, and arched back
are common during this stage. In cases where partial seizures occur,
the pet may run in circles, or appear blind or deaf.
What Tests Will My Veterinarian Run To Confirm That My Pet Has Epilepsy ?
After a thorough physical examination , your veterinarian will likey want to begin with a complete blood chemistry panel as well as a urinalysis of the pet's urine. If your pet is young or in mid-life and has simple or idiopathic epilepsy, these tests will probably all come back normal. (T4 could be low if the pet is already taking phenobarbital [ref]) If your veterinarian is reasonably certain of the diagnosis at that point, the vet might begin the pet on an anti-epileptic medication. When the diagnosis is not that certain, the vet can go on to order more specialized tests, such as an MRI, CT scan or even a cerebrospinal tap (vets often obtain that fluid higher up at the base of the pet's skull rather than low in the back) until a diagnosis can be made.
What Should I Do During The Seizure ?
When a first seizure occurs, owners tend to rush their pets to an emergency veterinary center. There is not much that can be done there for idiopathic epilepsy; but it is a wise thing to do considering all the serious conditions that can mimic epilepsy. Luckily, most epileptic seizures last only a few minutes. One to three minute seizures are most common. Those that last five to ten minutes are less common and more serious. I have never seen or heard of a dog that swallowed its tongue during a seizure. During a prolonged seizure, a dog's tongue and mouth can turn purple (cyanosis). But that is because it is having difficulty breathing, not because its airway is obstructed. Certain breeds with short faces (like bulldogs) spend their lives with borderline respiratory obstruction. Those pets, in seizure, are probably more at risk than others.
My first concern for my clients is that they NOT TO BE BITTEN. Do not put your hands in or near the pet’s mouth. If your pet or a neighbor’s pet develops a seizure, begin by placing the pet’s head on a soft folded towel or pillow. You may carry the pet in a blanket to a secluded tiled area. Remove all objects that surround the pet so it will not injure itself. Stay beside it until the seizure ends.
You can gently stroke and speak calmly and softly to your pet; but the pet will probably not know you are present until the seizure begins to subside.
Keep the room darkened, cool and keep other family members away. You can already position some paper towels and warm soapy water on a wash stand beyond the pet’s reach to help clean up any mess.
How Soon Should I Start To Think About Continuous Medications For My Pet ?
This is a difficult question to answer. I generally suggest that dogs and cats receive anti-seizure medications if they have had two or more seizures within an 12-week period or two or more cluster seizures (acute repetitive seizures) within a 4 week period. Dogs and cats that show unusually severe ictal or postictal periods should also begin medication. How frequently - if ever - that an owner can tolerate the sight of seizure behavior in their pet is also a major decision factor for many owners.
What Medications Are Available To Treat Epilepsy In Pets ?
Phenobarbital (aka Phenobarbitone)
Phenobarbital is the most commonly used drug to treat epilepsy in
dogs and cats.
The side effects of phenobarbital are sedation, increased appetite, weight gain, increased thirst and urination and sometimes harm to the liver over time. These problems can be minimized if the dose is closely regulated or if a combination of medications is used that lower the phenobarbital dose. My article on NeuroCare™ and MCTs suggests other possible ways. Phenobarbital works well in both dogs and cats. Cats do not seem as prone as dogs to liver damage while on this drug, but they do tend to gain weight.
Combining phenobarbital with a second drug, such as potassium bromide, may lessen the chances of liver damage by alowing a lower phenobarbital dose.
Some veterinarians suggest give epileptic pets milk thistle as a liver protectant. (A 2012 scientific study of milk thistle's "active" ingredient, silymarin, found it of little or no value in humans with one form of chronic hepatitis ref. A 2007 study had reached a similar conclusion on its use in various human liver problems. (ref) Silymarin is one of the two "active" ingredients in Denamarin. A 2016 study in mice was considerably more up beat. (ref)
Primadone (Mysoline, Mylepsin, etc.)
The effects and side effects of primadone are the same as phenobarbital. In your pet's body, much of the primadone is converted to phenobarbital which accounts for most or all of its anti-seizure effects.
Phenytoin (Dilantin, diphenylhydantoin)
This drug rarely controls seizures on its own. It should never be given to cats. It can also be toxic to the liver of dogs.
This drug is compounded by a number of special order veterinary pharmacies (It should be approved by the FDA as a prepackaged product in 2012) It can be used to lower the amount of phenobarbital your pet is given to hopefully decrease the likelihood of liver damage. Dogs taking potassium bromide should receive it with food. They need to be careful with the salt levels in their diet and whenever their brand of dog food is changed. Their T4 levels and serum bromide concentrations need to be periodically monitored. The most common side effects of this drug are behavioral changes, muscular twitching and staggered gait. You can read in detail about these side effects and others here. Most veterinarians rely on phenobarbital to get your pet's seizures under control and then add potassium bromide as a second line medication to keep the pets phenobarbital dose as low as possible. It is rarely used at this time as the primary seizure-control medication. (ref).
Cats do not respond as well to potassium bromide as dogs do. The use of this medication in cats has also been frequently associated with a type of lung inflammation called pneumonitis. (ref) When pneumonitis occurs, it can produce signs quite similar to feline asthma.
This drug alone is only good to end dangerous long-lasting seizures until another medicine can take effect. In dogs and cats, it is quite good at breaking a persistent, dangerous seizure; but when it is given over longer periods of time the body becomes resistant to its effects. It can be an effective "add-on" medication for epileptic cats because it seems to persist longer in the blood stream of feline than canine patients.
(Some newer drugs used in human epilepsy show promise in dogs.
These include clorazepate, felbamate, gabapentin, levetiracetam
and zonisamide. However, the dog's Liver
enzymes need to be monitored
closely, particularly if the dog receives zonisamide (ref)
Veterinarians have less experience using these newer anti-seizure medications than phenobarbital or potassium bromide. These newer medications were developed for human use and it is yet unclear what their long-term effects might be in dogs and cats. Veterinarians rarely use them when a pet's seizures can be adequately controlled using these two better-known, traditional medications. So use the newer ones all with caution and with frequent monitoring of your pet's blood blood chemistry. Periodic monitoring of all anti-seizure medication serum blood levels as well as their effects on your pet's liver and kidney function is always a good idea.
This drug can be used in conjunction with phenobarbital. It is moderately effective, but serum levels of the drug need to be monitored every 4-6 months as they tend to drift downwards. Clorazepate is similar in structure to diazepam (Valium) and like diazepam, it works well in emergencies. It is available in regular and time-release form. In dogs, both forms seem work the same. Because dogs vary greatly in how they absorb this drug, blood levels should be frequently checked. Side effects of clorazepate are sleepiness and a wobbly gait.
The primary advantage of felbamate is that it does not cause drowsiness. It is often given along with phenobarbital to lower the phenobarbital dose. The toxicity of this drug is very low but it has to be given several times a day. Blood samples should occasionally be taken to check for liver toxicity and bone marrow suppression, which are uncommon side effects.
This drug also causes little to no sedation. It is sometimes given successfully to pets to supplement to other anti-seizure medication such as phenobarbitol and bromide when they do not control seizures well enough on their own. When using Neurontin, always try to stay at the lowest possible dose. A few veterinarians have found it helpful but many have not. You can read an article on it's use here.
This medication has been used in dogs in combination with phenobarbital and potassium bromide to lower the daily dose of phenobarbital received and in cases where phenobarbital was not able to control the seizures alone. The drug appears quite safe. Rare side effects in dogs include stiff wobbly gait, vomiting and salivation. It's cost is high and it requires frequent dosing.
This drug is sometimes effective in blocking seizures and has few side effects that we know of. When it is used, it is usually an add-on therapy for dogs already receiving phenobarbital. When this drug is used, the phenobarbital dosage can sometimes be drastically reduced or , perhaps, entirely eliminated.
This medicatin works quite well in dogs and is a common alternative medication to phenobarbital in Europe. But as of 2017, it is still not available in the United States through commercial channels. Read about Pexion here.
Valproic Acid (Depakote®)
This medication does not work as well in dogs and cats as it does in people with epilepsy. It can be quite toxic to cats. It is occasionally used to supplement other anti-seizure medications in pets. It can cause the pet to loose hair and it can be toxic to the liver. It can cause drowsiness, sedation, nausea and vomiting. It is best given with food.
Can I Ever Stop Giving My Pet Medications ?
Pets that were put on long term phenobarbital because their pet had one or two seizures probably shouldn't be on it at all. But if your pet had multiple seizures that were determined to be idiopathic epilepsy, I suggest not attempting to lower or discontinue medications until your pet has been free of seizures for a year. Do not change or discontinue medications without the knowledge of your veterinarian and schedule any changes so that seizures are unlikely to occur on weekends, holidays or periods when your regular veterinarian is not likely to be available. If seizures frequently reoccur, your pet will probably need its medications for its lifetime.
Might My Pet's Diet Affect The Number and Intensity of Its Seizures ?
There is some evidence that in humans at least, diets high in fat and low in carbohydrate might be beneficial in controling epilepsy. You can read a review of that information here. (I would caution you against feeding your pet any diet that contains raw meat. That is because the threat of infection from contamination of these products is greatly increased when a pet has chronic health problems of any kind.) Be sure to read the link to the NeuroCare diet as well. You might also try to slowly changing the amounts you feed at each meal and the frequency between them. Smaller, more frequent feeding are known to change many aspects of metabolism - sometimes for the better.
Will Idiopathic Epilepsy Shorten My Dog's Life ?
Typically, idiopathic epilepsy will not shorten your dog's life.