Seizures

 

Seizures are one of the most frequently reported neurological conditions in dogs. Seizures do occur in cats too, but less frequently than dogs. The information below is tailored to dogs, but is generally the same for cats. A seizure may also be called a convulsion or fit and is a temporary involuntary disturbance of normal brain function that is usually accompanied by uncontrollable muscle activity. Epilepsy is used to describe repeated episodes of seizures. With epilepsy, the seizures can be single or may occur in clusters, and they can be infrequent and unpredictable or may occur at regular intervals. Status epilepticus is a serious and life threatening situation. It is characterized by a seizure that lasts more than five minutes. Unless intravenous anticonvulsants are given immediately to stop the seizure activity, the dog may die or suffer irreversible brain damage. If status epilepticus occurs, you must seek treatment by a veterinarian immediately.

There are many causes of seizures. Idiopathic epilepsy, the most common cause of seizures in the dog, is a genetic disorder, but its exact cause is unknown. Other causes include liver disease, kidney failure, brain tumors, brain trauma, or toxins.

Seizures often occur at times of changing brain activity, such as during excitement or feeding, or as the dog is falling asleep or waking up. Affected dogs can appear completely normal between seizures.

 

Epilepsy Classifications:

–Primary or genetic epilepsy, generally a lowering of the animal’s seizure threshold, is thought to be genetic or inherited in origin with no active disease process causing the seizures and typically manifests between 1-5 years of age. Eccentric presentations can occur. There are no specific tests for primary or genetic epilepsy, diagnosis made by ruling out other known causes of seizures.
–Cryptogenic epilepsy results in seizures believed to be the result of structural lesions of the brain which eludes identification with normal advanced brain diagnostics leading to seizures, like glial scars, errors of inborn metabolism, etc.
–Symptomatic epilepsy results in seizures from an identifiable structural lesion of the brain, like neoplasia, cystic, or inflammatory diseases
–Reactive epilepsy results in seizures due to metabolic or toxic diseases.

 

Seizures consist of 3 components:

1)  The pre-ictal phase, or aura, is a period of altered behavior in which the dog may hide, appear nervous, or seek out the owner. It may be restless, nervous, whining, shaking, or salivating. This may last a few seconds to a few hours. Sometimes this stage is too short to notice. This period precedes the seizure activity, as if the dog senses that something is about to occur.

2)  The ictal phase is the seizure itself and lasts from a few seconds to up to five minutes. During a seizure, the dog may lose consciousness or may just have a change in mental awareness (“absence” seizures or hallucinations such as snapping at invisible objects). If the dog experiences a grand mal, or full-blown seizure with loss of consciousness, all of the muscles of the body contract spastically and erratically. The dog usually falls over on its side and paddles its legs while seeming to be otherwise paralyzed. The head will often be drawn backward. Urination, defecation, and salivation may occur. If the seizure has not stopped within five minutes, the dog is said to be in status epilepticus or prolonged seizure. Status epilepticus is considered an immediate emergency and medical help should be sought.

3)  During the post-ictal phase or the period immediately after the end of the seizure, there is confusion, disorientation, salivation, pacing, restlessness, or even temporary blindness. There is no direct correlation between the severity of the seizure and the duration of the post-ictal phase. This stage typically last a few minutes to a few hours, but some dogs will appear post-ictal for up to 24 hours, especially if cluster seizures occurred.

 

Types of seizures:

Numerous types of seizures are described, but basically can be broken down to 2 broad types:generalized and focal. Generalized are the more severe looking seizures that people typically envision or have seen on TV. Focal seizures can look very different and frequently veterinarians are even unsure if the episode is even a seizure at all. Below are examples of both.

1. Generalized seizures of which tonic-clonic is the most common. Click here for video.
2. Focal seizures. Click here for video. 

 

What to do in the event of a seizure:

Despite the dramatic and violent appearance of a seizure, seizures are not painful, although the dog may feel confusion and perhaps panic. Contrary to popular belief, dogs do not swallow their tongues during a seizure. If you put your fingers or an object into its mouth, you will not help your pet and you run a high risk of being bitten very badly or of injuring your dog. The important thing is to keep the dog from falling or hurting itself by knocking objects onto itself. As long as it is on the floor or ground, there is little chance of harm occurring.

A single seizure is rarely dangerous to the dog. However, if the dog has multiple seizures within a short period of time (cluster seizures), or if a seizure continues for longer than a few minutes, the body temperature begins to rise. If hyperthermia or an elevated body temperature develops secondary to a seizure, another set of problems may have to be addressed.

In the event of a seizure:

• Try to remain calm as best you can.
• Do not physically restrain your pet, but ensure they do not fall off the bed, down stairs, etc.
• Do not put your hands in their mouth
• Administer any medications (i.e. rectal or intranasal) that have been previously recommended.
• Log the seizure in your diary
• Call your veterinarian if cluster seizures occur or in the event of prolong seizures (> 5 min)
• Administer any post-seizure medication previously recommended once your pet is able to swallow
• Provide a safe, low-free, low-light environment, without other animals while you pet is recovering.

Prognosis:

The prognosis for genetic epilepsy is generally fair to good long term. Most dogs with epilepsy can be well controlled on 1 or 2 seizures medications. About 25% of dogs with epilepsy will be refractory to medications and require more aggressive therapy. The goal of the seizure medications is to reduce the frequency of the seizures as much as we can while minimizing side effects. Almost all dogs will still have some seizures. Changes to medications are made following trends, not individual seizures. Average survival time for dogs with epilepsy is around 8 to 11 years, but this depends a lot on when the seizures first start. The two most common reasons for this is actually not death during a seizure (although this does infrequently occur), but rather they are euthanized due to poor quality of life, either from excessive seizure activity or from side effects of medications.

The prognosis for other causes of seizures is variable depending on the cause.

 

Treatment:

Numerous medications exist to help control seizures. They all have pros and cons and there is no one ‘right way’ to control seizures. Frustratingly, treatment of seizures is largely trial and error. Every dog will respond differently to the same medication.

Common medications:

• Zonisamide
• Levetiracetam (Keppra)
• Phenobarbital
• Potassium Bromide
• Gabapentin
• Pregabalin
• Topiramate (Topamax)
• Diazepam (Valium)

 

Other treatment consideration:

• It is important to avoid over stimulation, elevated body temperatures and over excitement. A constant sleep routine is also beneficial to help improve seizure control. A set bed time should be instituted and maintained. Sleep deprivation or wide fluctuations in sleep periods can also be seizure-genic in animals with primary epilepsy.

• Dietary intolerances: There is plentiful anecdotal and growing scientific evidence that some people with epilepsy can reduce or eliminate their seizures (and other neurologic disorders) simply be removing grains and gluten from their diet. These ingredients (and others) have been shown to be pro-inflammatory especially in the GI tract which can in turn spark neurologic abnormalities. We are unsure if this is true in animals; however I would encourage all to make the shift to a gluten free diet if possible.  http://www.dogfoodadvisor.com/ is a great resource to evaluate dog foods.

• The use of cannabis in medicine is exploding. One non-traditional consideration for possibly improving seizure control is to consider a nutraceutical product available from Canna-Companion.  This cannabinoid product is a legal supplement and would be an adjuvant to your pet’s current anticonvulsants. It may help reduce the amount of anticonvulsants needed, but will not replace anticonvulsant therapy altogether. It is legal to purchase as a supplement because it has very minuscule amounts of THC, the psychoactive property of the cannabis plant but it is very high in cannabidiol (CBD), which is the active ingredient credited with anti seizure effects as well as other benefits to the body. The product has increased levels of phytocannabinoids as well as B vitamins, fatty acids, and flavonoids; all beneficial in decreasing inflammation and providing analgesic effects. It is much higher in CBD than cannabinoid oils and more likely to have the desire effect than cannabinoid oils for trying to improve seizure control.

• Some dogs will benefit from acupuncture, which can reduce seizure frequency. This may be another non-traditional treatment to consider.

• A ketogenic diet is a special high-fat, low-carbohydrate diet that helps to control seizures. This is a commonly used strategy in people with epilepsy, but is rarely done in animals because of the logistics involved. The name ketogenic means that it produces ketones in the body (keto = ketone, genic = producing). Ketones are formed when the body uses fat for its source of energy. Usually the body uses carbohydrates for its fuel, but because the ketogenic diet is very low in carbohydrates, fats become the primary fuel for the brain instead. The exact mechanism of how ketones reduce the seizures is unknown but numerous studies have shown evidence that it works. Because the logistics of developing a ketogenic are difficult, this strategy is rarely discussed, however for pet owners that are willing to make their own food at home, this could be considered a viable option, especially for those with refractory epilepsy.