Canine Epilepsy


Canine epilepsy (Primary or Idiopathic Epilepsy) is the commonest cause of seizures in dogs. Idiopathic epilepsy is a brain disorder characterized by recurrent seizures (fits) in the absence of any brain lesion. Although the cause for this is typically unknown, epilepsy appears to be inherited in certain breeds.

Are all seizures caused by epilepsy?

No. Dogs may have seizures that are caused by metabolic disorders, head injuries, poisoning, brain lesions, etc. If your dog has had a fit, it is important to consult a veterinarian in order to determine the cause of your pet’s disorder.

How do I recognize a seizure?

It is often difficult to differentiate a true seizure from other similar episodes, such as fainting, collapse, vestibular disease, etc. Most seizures occur when the animal is resting or asleep, usually at night or early morning. There are three distinct phases to a seizure:

1. Pre-ictal phase: before a seizure develops, the owner may notice a period of altered behaviour where the dog appears anxious, and either hides or seeks out its owners.

2. Ictal phase: this is the period of the seizure itself, usually lasting 1-5 minutes, where the dog may show any combination of the behaviours listed below:

• Loss of consciousness
• Stiffness or rigidity
• Chewing movements
• Profuse salivation
• Uncontrollable urination
• Uncontrollable defecation
• Vocalization
• Paddling of all 4 limbs

3. Post-ictal phase: this period can last from seconds to hours and lasts till the dog returns to normal. In this period, your dog may be lethargic or depressed, may eat or drink compulsively, appear blind or deaf, or pace restlessly.

Seizure activity that extends beyond 10 minutes is referred to as status epilepticus and considered a life-threatening emergency – most animals will die or have persistent brain damage if they are not controlled within a period of 45 minutes.

Cluster seizures are multiple seizures occurring within a short period of time with only brief periods of consciousness between them. Cluster seizures, like status epilepticus, can be life-threatening, and warrant immediate veterinary assistance.

What should I do if my dog has a seizure?

Watching a dog have a seizure can be an unnerving experience, but it is important to remain calm. Try to move the dog to a safe place where it is unlikely to injure itself. Remove any other dogs. Never stick your hand in the dog’s mouth – the dog will not swallow its tongue.

Time the length of the seizure and observe the dog closely so you can describe the seizure later to the veterinarian. Try to comfort and soothe your dog once it is in the post-ictal stage. Your dog may not need emergency care for an isolated fit, but an appointment with a veterinarian should be promptly scheduled.

How do dogs develop epilepsy?

The age of onset for seizure activity is usually 6 months to 3 years, although some dogs develop epilepsy as old as 6 years. Often the prognosis is worse for dogs with an onset before 2 years of age.

In most cases the epilepsy is considered idiopathic – the cause is unknown. However, there are at least 25 breeds that are believed to have a genetic predilection to epilepsy:

Beagles, Belgian Tervurens, Boxers, Border Collies, Cocker Spaniels, Dachshunds, Dalmatians, German Shepherds, Golden Retrievers, Irish Setters, Irish Wolfhounds, Keeshonds, Labrador Retrievers, Pointers, Poodles, Saint Bernards, Schnauzers, Siberian Huskies, Hungarian Vizslas, Welsh Springer Spaniels, and Wirehaired Fox Terriers. If your dog has been diagnosed with epilepsy, it should not be bred from.

How does the vet diagnose this disease?

Diagnosis is usually based on the relevant history (e.g. breed, recent seizure activity), physical and neurological exam, blood test and urine test to ensure that there are no underlying metabolic disorders. Your veterinarian may also suggest further tests such as a cerebrospinal fluid (CSF) tap, an electroencephalogram (EEG), a CT scan, or MRI.

What is the treatment for epilepsy?

If your veterinarian determines that your dog needs anticonvulsant therapy, the medication of choice is Phenobarbital. Phenobarbital is safe, inexpensive, and is usually given twice a day. It will take some time before the Phenobarbital reaches the correct level in your pet’s blood. Regular blood tests are required to monitor Phenobarbital levels and to ensure that the drug is not causing significant liver damage. If the Phenobarbital is ineffective at preventing seizures, potassium bromide is added to the treatment.

Will anticonvulsant therapy stop my dog from fitting?

Unfortunately, perfect control of epilepsy is rarely achieved. However, the use of anticonvulsant therapy will decrease the frequency, severity and length of the seizures. Dogs that are not on medication tend to have an increase in the frequency of seizures.

(photo: protographer23)