WHAT IS A SEIZURE?
Seizures are the result of muscle responses to an abnormal nerve-signal burst from the brain. They are a symptom of an underlying neurological dysfunction. Toxic substances, metabolic or electrolyte abnormalities and/or imbalances cause an uncoordinated firing of neurons in the cerebrum of the brain, creating seizures from mild, .petit mal. to severe, .grand mal. However, there is no test in the medical industry for the existence of epilepsy (primary, inherited or idiopathic). To determine whether a dog has epilepsy or something else, a veterinarian or neurologist arrives at their diagnosis by a process of elimination. Idiopathic epilepsy, the single most common canine seizure disorder, is reported to occur in anywhere from 0.5 to 5.7 percent of all dogs. It’s important to remember that seizures themselves are almost never fatal. When seizures occur in clusters, however, dogs are prone to developing status epilepticus, a condition characterized by continuous, uncontrollable seizure activity. Continuous seizures can lead to exhaustion, hypoglycemia, hyperthermia, oxygen depletion, brain damage, and eventually, death. Status epilepticus is an extreme emergency and often requires general anesthesia for prolonged periods of time to control.
The first seizure in a dog with primary epilepsy usually occurs between the ages of 6 months and 5 years. (Oliver, Seizures). However, a diagnosis of primary epilepsy is not proof of a genetic defect; only careful breeding studies could prove that. The breed, the age, and the history may suggest a genetic basis for primary epilepsy if there is a familial history of seizures.
Secondary epilepsy refers to seizures for which a cause can be determined, and there are many. In dogs less than one year of age, the most commonly-found causes of seizures can be broken down into the following classes: degenerative (storage diseases); developmental (hydrocephalus); toxic (lead, arsenic, organophosphates, chlorinated hydrocarbons, strychnine, tetanus); infectious (distemper, encephalitis, and others); metabolic (such as transient hypoglycemia, enzyme deficiency, liver or kidney failure); nutritional (thiamine, parasitism); and traumatic (acute injury). In dogs 1-3 years of age, a genetic factor is most highly suspected. In dogs 4 years of age and older, seizures are commonly found in the metabolic (hypoglycemia, cardiovascular arrhythmia, hypocalcemia, cirrhosis) and neoplastic (brain tumor) classes. (Oliver, Seizure). Dr. Jean Dodds has mentioned that seizures are also associated with hypothyroidism, which is a familial (inherited) autoimmune disease of purebred dogs.
FOUR SEIZURE STAGES
The four stages to a seizure consist of the Prodome(may precede the seizure by hours or days. It is characterized by changes in mood or behavior.), Aura(signals the start of a seizure. Nervousness, whining, trembling, salivation, affection, wandering, restlessness, hiding and apprehension are all signals.), Ictus(A period of intense physical activity usually lasting 45 seconds to 3 minutes. The dog may lose consciousness and fall to the ground. There may be teeth gnashing, frantic thrashing of limbs, excessive drooling, vocalizing, paddling of feet, uncontrollable urination and defecation.), and Post Ictus/Ictal(after the seizure, the dog may pace endlessly, appear blind and deaf and eat or drink excessively.). Some dogs will show signs of restlessness during the first two stages, while others do not. The Ictus is the actual seizure/convulsion and could last 45 seconds to 3 minutes. Loss of consciousness, thrashing of limbs & teeth, as well as uncontrollable muscle movement & loss of bodily functions are common. The Post Ictus (after seizure) behavior may consist of disorientation, wandering, blindness, excessive hunger, and thirst. It can last minutes to days.
THE CAUSE:
Anything that disrupts normal brain circuitry: Idiopathic Epilepsy: Meaning no known cause and possibly inherited. This is also referred to as
Primary Epilepsy. Check history of pedigree and make sure your veterinarian has looked for possible underlying factors. Seizures caused by underlying factors are referred to as Secondary Epilepsy. The following tests are advised before a diagnosis of idiopathic/ primary epilepsy is made.1) CBC, Chem screen and bile acids
2) Glucose . . . to check for hypoglycemia.
3) Thyroid Panel – 6 tests, to check for low thyroid function/hypothyroidism.
4) EEG . . .to see if there are findings suggestive of a lesion (an abnormal EEG is standard with epilepsy, but a vet or a physician will also be able to tell if there is a lesion.
5) Blood test for lead poisoning . . .
6) Cerebrospinal fluid analysis . . .to look for encephalitis, distemper and other infection.
7) CT scan/MRI . . .-to look for a brain lesion
8 Fecal Parasite
TYPES OF SEIZURES
If you believe your dog is having a seizure, it is important to note all the details in a journal so that you may accurately describe it to your veterinarian.
• Generalized Seizure: Tonic-clonic (may be Grand Mal or Mild): In the grand mal seizure, the tonic phase occurs as the animal falls, loses consciousness, and extends its limbs rigidly. Respiration may stop (apnea). This phase usually lasts 10-30 seconds before the clonic phase begins. Clonic movements include paddling of the limbs and/or chewing. Other signs that may appear during the tonic or clonic phase are dilation of the pupils, salivation, urination, and defecation.
• Petit Mal Seizure (A.K.A. Absence seizure): Signs are brief (seconds) duration of unconsciousness, loss of muscle tone, blank stare, momentarily staring into space and possibly upward rotation of eyes.
• Partial Seizures: Movements are restricted to one area of the body, such as muscle jerking, movement of one limb, turning the head or bending the trunk to one side, or facial twitches. A partial seizure can progress to (and be mistaken for) a generalized tonic-clonic seizure, but the difference can be established by noting whether or not a seizure starts with one specific area of the body.
• Complex Partial Seizures (A.K.A. Psychomotor or Behavioral): Seizures are associated with bizarre or complex behaviors that are repeated during each seizure. Dogs may exhibit lip smacking, chewing, fly biting, aggression, vocalization, hysterical running, cowering or hiding in otherwise normal animals. There is an obvious lack of awareness though usually not loss of consciousness. Abnormal behaviors may last minutes or hours and can be followed by a generalized seizure.
• Cluster Seizures: Multiple seizures within a 24- hour period with only brief periods of consciousness in between. May be confused with status epilepticus. continuous seizure lasting 30 minutes or more, or a series of multiple seizures in a short time with no periods of normal consciousness. It can be difficult to tell status epilepticus from frequent cluster seizures; but both are considered life-threatening emergencies. Contact your Vet!
Most status patients usually suffer from generalized tonic-clonic seizures.
DURING A SEIZURE:
• Some dogs are light or sound sensitive during seizure episodes. Try dimming the lights and keeping loud noise at a distance from the dog.
• Calling the dog.s name to bring them out of the seizure may sometimes work, but most seizures will run their course.
• A fan blowing on the dog, or rubbing the feet and belly with cool (not cold) water may help cool the dog down. Should the dog seem to be overheating due to repeated seizures or not coming out of a seizure – IMMEDIATELY
bring the dog to/or contact a vet since overheating can be very dangerous.
• Many dogs are confused and even blind right after a seizure. Keep the dog in a safe area where they cannot fall down stairs, get tangled in cords, break glass, fall into a pool, or hurt themselves.
Keep your hands away from the dog.s mouth! Other dogs in the household may attack a seizing animal, so it is important to keep animals separated while you aren.t at home. I.D. tags
stating that the dog has seizures are important if your dog wanders away from home.
• Write down all circumstances surrounding the seizure, such as changes in food, unusual activities, and medication or vaccinations recently given. Other triggers for seizures may be Flea &
Heartworm treatments, yard chemicals for weeds and insects, and household cleaners.
• Be prepared to transport a dog that cannot stand up and walk, or is even in the middle of a seizure. Hard plastic children.s sleds can be used to carry or drag the dog to the car. A heavy blanket folded can also act as a stretcher.
TREATMENT:
Medical treatment is generally advised for animals that have one or more seizures per month. Animals who have cluster seizures or go into status epilepticus may be treated even though the rate of incidence is less than once per month. Successful drug therapy depends upon the owner.s dedication to delivering the drug exactly as prescribed with absolutely NO changes in the dose or type of medication without consultation. Haphazard drug administration or abrupt changes in medication is worse than no treatment at all, and may cause status epilepticus.
It is important to remember that the goal of treatment is to decrease the frequency and severity of seizures and avoid unacceptable side effects. It may not be possible to stop the seizures altogether.
• Phenobarbital is one of the most commonly prescribed drugs. It is possible that dogs may rapidly develop tolerance to the effects of Phenobarbital.
At high concentrations, persistent depressive side effects may appear. Dogs may eat or drink more than their usual amounts. Liver function can be impaired over time. If use of the drug is terminated, signs of physical dependence may develop. There is danger of triggering status epilepticus during withdrawal. Dosages should be gradually reduced in small steps over a prolonged period.
• Primidone.s side effects include sedation when treatment is initiated, and eating or drinking more than usual. High concentrations of liver enzymes have been reported with prolonged treatment at high dosages. Primidone is broken down to Phenobarbital in the liver.
• Diazepam (Valium) is used for treatment of status epilepticus. Phenytoin (Dilantin), Carbamazine, and Valproic Acid are not currently recommended for use.
• Potassium Bromide (KBr) is gaining new recognition for use in refractory (difficult to control) canine epilepsy. It is the anticonvulsant of choice for dogs with liver disease. Sodium Bromide is preferred for dogs with kidney problems. Combining Potassium Bromide or Sodium Bromide with Phenobarbital may be useful for patients who do not respond well to Phenobarbital or Primidone alone. KBr is being used successfully alone in some cases. Side effects of bromide toxicity (Bromism) CAN include uncoordination, depression, muscle pain, and stupor.
Gabapentin is a newer drug being used for humans. It does offer exciting possibilities for dogs as it is only partially metabolized by the liver. At present it is very costly to use around $250.00 a month, however with the few dogs that have used it, the results have been very positive.
Low Thyroid Function – Hypothyroidism & Seizures
Seizures are one of the symptoms of hypothyroidism along with chronic skin disease, hair loss, weight gain, lethargy and slow metabolism, behavioral changes (aggression, hyperactivity, poor concentration, passivity, phobias, anxiety.) A recent study of 634 dogs showed that 77% of the dogs who were hypothyroid also had seizures. Dr William Thomas, a board certified neurologist, had this to say about thyroid testing:
“Thyroid testing should be considered in any dog with recurrent seizures. Such testing is relatively inexpensive and carries little risk to the patient. Any dog that is diagnosed with hypothyroidism by appropriate testing should be treated with thyroid replacement therapy. This applies to all dogs, whether or not they suffer seizures. If the seizures improve with thyroid therapy, then great! If not, the patient should still be treated because hypothyroidism can cause many other health problems. Appropriate use of thyroid medication is one of the safest and effective treatments available in veterinary medicine. ” WB Thomas DVM, Dipl.ACVIM (Neurology) University of Tennessee, Knoxville, TN
It is a good idea to have a full thyroid panel of 6 different tests to determine if your dog is hypothyroid. The tests you want to have done are T3, T4, free T3, free T4, T3 and T4 Autoantibodies. Two or three thyroid tests (e.g.T4, free T4 or TSH), are not conclusive for hypothyroidism. You need all 6 tests listed. Proper thyroid medication may reduce or eliminate seizures.
Diet:
Diet plays an important role in the management of Canine Epilepsy. It is very important to feed a kibble that is preservative free. Preservatives such as Ethoxyquin and BHT, BHA should be avoided as they can cause seizures. Many “Supermarket ” foods are loaded with chemical dyes and preservatives, buy a high quality kibble made from “human grade” ingredients or better yet cook for your dog or feed a raw ( BARF) diet. Many recipes can be found in Dr Pitcairn’s Complete Guide to Natural Health for Dogs and Cats. Two helpful books on a raw diet are Dr Ian Billinghurst’s “The BARF Diet” & Susan Johnson’s “Switching to Raw”. There is also a good article on the web site called “The Role of a Healthy Diet in the Management of Canine Epilepsy” PLEASE NOTE: If your dog is taking Potassium Bromide be very careful when you switch dog foods. Try to make sure the chloride content is the same as the previous food. Change over very slowly, whether it is the same chloride content or different, so that the absorption rate of the KBr remains constant.
SUSAN WYNN, DVM says: “Dogs evolved from Canis lupis – the wolf. Wolves eat caribou or the like, but if they are forced, they will eat smaller game (rarely). They have been observed to graze on grass, eat berries, etc, but only when they need to. This is our lesson in canine nutrition – they are omnivores who do well with fresh meat, the vegetation they get in a caribou stomach (which is mostly green, unless the beast is eating from baited fields), and a smattering of other stuff if they are hungry.
Food companies have, in the main, revolutionized pet nutrition by eliminating major nutritional deficiencies and providing optimal nutrition for the average pet. Our concern, however, is not for the average pet. It is for the sick pet. If epileptic animals have a disease with even a small nutritional component, wouldn’t we want to deal with it? Is your epileptic animal showing other signs of allergies? If s/he is chewing feet, scratching ears, having anal gland problems, vomiting bile seasonally, etc., etc., one may want to consider dietary changes, including hypoallergenic diets, if appropriate.
I think that the main benefit of feeding real food meat, – (raw or cooked, raw or steamed veggies, cooked grains) – is to provide stuff that is killed in the kibble extrusion process. If you or I were to eat a diet of Wheaties, yogurt, VegAll, and Spam day after day for 20 years, would this be enough? I don’t know, but it makes me uncomfortable. I think our pets need a more varied diet and a fresher one than we can give them with commercial kibble. So I do recommend supplementing pet food with lean meat and vegetables.”
Environment:
It is important to keep your epileptic dog as free from chemical pollutants as possible. Think about the environment your dog is living in. Do you use chemical sprays on your lawn? Dogs will sometimes seize only when the lawn is sprayed for weeds. How about the cleaner you use for the floor? Some dogs have been known to seize after the floor has been washed with a pine scented cleaner. Flea and tick medications can also cause seizures. It is recommended that epi dogs be given Interceptor as a monthly heartworm preventative and Frontline used for fleas. Avoid products with Ivermectin it has been known to cause seizures in some breeds. There are many things that can lower a dog’s seizure threshold. Keep a diary of your dog’s seizures. Note down anything you have done or that the dog could have come in contact with that day which could have contributed to seizure. It is also a known phenomenon that some dogs may seizure around the full moon.
Vaccinations:
Vaccinations can lower a dog’s seizure threshold and trigger a seizure. If you feel that this is the case for your dog, ask the vet to split the shots, give them separately at weekly or two weekly intervals and ask for the Rabies shot to be given 2 weeks after that. Ask your vet if he/she knows about the new 3-year protocol now being used by many vets and veterinary schools.
There is a K9Epileptic Yahoo Group that one can also join. Much of what I have researched is from them on various information they have made an effort to get out to the public in educating.