Canine epilepsy is a chronic condition characterized by recurrent (repeated) seizures (convulsions, fits). An epileptic seizure is the clinical manifestation of abnormal brain activity in the cerebral cortex. Epilepsy requires lifelong care.
Common names: Convulsions, Seizures, Fits.
Scientific names: Idiopathic epilepsy (primary, genetic, true, or inherited epilepsy), Secondary epilepsy.
Primary epilepsy is more common in large-breed dogs from 1 to 5 years old. The incidence is slightly more common in males. All breeds, including mixed breeds, are susceptible. Some breeds (beagles, dachshunds, keeshonden, German shepherds, Belgian Tervurens, Labrador retrievers, golden retrievers, collies, and others) have higher incidence due to genetic predisposition.
The incidence of primary epilepsy in dogs is believed to be 1 to 2 percent.
There is no known geographic distribution.
Clinical signs (primary, most to least frequent, scientific term, synonyms)
Generalized tonic-clonic seizures (grand mal, full body) most common.
Status epilepticus is a condition when a seizure lasts for more than five minutes or a series of multiple seizures occurs over a short period of time, but the dog never completely regains consciousness.
Cluster seizure refers to multiple seizures within a short period of time with only brief periods of consciousness between.
Clinical signs (secondary, most to least frequent, scientific term, synonyms)
Salivation, vomiting, urination, defecation, Tiredness (lethargy), disorientation, blindness.
Causes (scientific, common term)
Idiopathic epilepsy is defined as an unknown etiology and may be inherited (genetic predisposition) in some breeds, Secondary epilepsy can be caused by metabolic disorders (hypoglycemia), infections (canine distemper), poisoning (lead, pesticides, snail bait, antifreeze), head injuries, brain tumors or congenital defects.
Organ systems affected (most to least affected)
Central nervous system, Gastrointestinal, Diagnostic tests, Physical examination, Chemistry analysis, Complete blood count, Cerebrospinal-fluid analysis, Radiographic examination of the head, Brain computed tomography (CT scan), magnetic resonance imaging (MRI).
A veterinarian will help differentiate between primary and secondary epilepsy. Portosystemic shunt, Hepatic encephalopathy.
Canine epilepsy is a chronic condition characterized by recurrent (repeated) seizures (convulsions, fits) affecting about 1 percent of the canine population. An epileptic seizure is the clinical manifestation of abnormal brain activity in the cerebral cortex.
Clinical manifestation of seizures can be mild (petit mal) or generalized, full body (grand mal). Epilepsy can be idiopathic (also known as primary, genetic, true and inherited) when the underlying cause is not known, or secondary (secondary to a disease, poisoning, or metabolic disorder) when the cause of the seizures is known.
There are four stages of seizures:
(1) Prodome: Precedes the actual seizure and may last from hours to days. The dog may show behavioral or mood changes (fear, hiding, aggression, barking).
(2) Aura: Signals start of the seizure. The dog may show restlessness, pacing, licking, salivation, trembling, whining, and barking.
(3) Ictus: Is period of actual seizure generally lasting one to two minutes characterized by loss of consciousness, falling over, involuntary extension of the limbs and paddling. Dogs might vocalize, foam or drool; urinate or defecate involuntarily; or have involuntary chewing motions.
(4) Postictal: Stage may last from minutes to hours to days and occurs immediately after a seizure. Dogs may appear tired, be disoriented, or have transient memory losses or blindness. Status epilepticus is a condition when a seizure lasts for more than five minutes or a series of multiple seizures occurs over a short period of time, but the dog never completely regains consciousness. Cluster seizure refers to multiple seizures within a short period of time with only brief periods of consciousness in between.
Primary epilepsy is more common in large-breed dogs from 1 to 5 years of age. The incidence is slightly more common in males. All breeds, including mixed breeds, are susceptible. Some breeds (beagles, dachshunds, keeshonden, German shepherds, Belgian Tervurens, Labrador retrievers, golden retrievers and others) have higher incidence due to a genetic predisposition.
Primary epilepsy is diagnosed by a veterinarian based on history of recurrent seizures and recovery in between seizures, typical age of onset, and exclusion of other potential causes (secondary causes) based on laboratory tests.
Immediately separate the seizuring dog, and move the pet to a relatively dark and quite place. Long-term medical treatment (months to years), depending on the frequency and severity of the seizures, may be prescribed by a veterinarian for animals that have one or more seizures per month.
Status epilepticus and cluster seizures require immediate emergency care by a veterinarian because these can lead to life-threatening complications (increased body temperature from muscle activity and brain damage if breathing is compromised). Some of the commonly used prescription anticonvulsants are phenobarbital, diazepam, potassium bromide, phenytoin and gabapentin.
Success of therapy depends on the pet parent's commitment to giving medications as prescribed for the life of the pet. Epilepsy cannot be cured but can be controlled. A record or diary of all seizure episodes should be maintained by the owner and reviewed with the veterinarian every six to 12 months or earlier if needed. Sometimes a combination of anticonvulsants or dose adjustment may be required for dogs that develop resistance to their medication.
Most dogs on anticonvulsant medications lead healthy, normal lives. About 30 percent of epileptics do not respond appropriately to anticonvulsant therapy.
Shell, LG. Diseases of the Cerebrum. In: Leib, MS, Monroe, WE, ed. Practical Small Animal Internal Medicine. Philadelphia: W. B. Saunders Company, 1997; 493-499.
Thomas, WB. Idiopathic Epilepsy. In: Cote, E. ed. Clinical Veterinary Advisor: Dogs and Cats. St. Louis: Mosby Elsevier, 2007; 351-353.
Safdar Khan, DVM, PhD, DABVT, DABT
Steven Hansen, DVM, MS, MBA, DABT, DABVT
Copyright 2007. The American Society for the Prevention of Cruelty to Animals (ASPCA)