Epilepsy in Dogs

Epilepsy is a term used for recurring seizures. In dogs, seizures may be caused by idiopathic epilepsy, structural brain disease, or reactive causes such as toxins or metabolic problems. Idiopathic epilepsy is the most common long-term epilepsy diagnosis in dogs and is often presumed to have a genetic basis when no other cause is found.

Risk factors and common causes include:

• Idiopathic epilepsy, often suspected in dogs with repeated unprovoked seizures and no clear underlying cause
• Genetic predisposition in some breeds
• Structural brain disease such as inflammation, congenital abnormalities, trauma, stroke, or brain tumors
• Reactive seizures from problems outside the brain, including toxin exposure or metabolic disease; these are seizures, but not true epilepsy if the trigger is transient
• Age at first seizure, which helps guide the workup; idiopathic epilepsy commonly begins between 6 months and 6 years of age
• Breed predispositions reported in dogs such as Beagles, Bernese Mountain Dogs, Border Collies, Boxers, Cocker Spaniels, Labrador Retrievers, and Golden Retrievers
• Male dogs may be at somewhat higher risk for idiopathic epilepsy in some populations

Epilepsy is a diagnosis of exclusion, which means your veterinarian must look for other reasons a dog might have seizures before labeling it epilepsy.

At the appointment, your vet may:

• Ask for a detailed history, including age at first seizure, how long episodes last, recovery time, toxin exposure, diet changes, and any previous illnesses
• Review a video of the event if you have one
• Perform a physical and neurologic exam
• Run bloodwork and urinalysis to check for metabolic disease, organ dysfunction, blood sugar problems, electrolyte changes, or other triggers
• Recommend additional tests such as bile acids when liver disease is a concern
• Consider chest or abdominal imaging if another underlying disease is suspected
• Refer for MRI or CT and cerebrospinal fluid testing when structural brain disease is a concern, especially if the neurologic exam is abnormal, the dog is very young or older at onset, or the seizure pattern is unusual

Dogs with likely idiopathic epilepsy often have seizure onset between 6 months and 6 years, are normal between seizures, and have no interictal neurologic deficits on exam.

Treatment focuses on reducing seizure frequency and severity, protecting quality of life, and managing emergencies if they occur. Many dogs need long-term therapy, and once anti-seizure medication is started it often continues for life.

Common treatment approaches include:

• Anti-seizure medications prescribed by your veterinarian; commonly used options include phenobarbital, potassium bromide, levetiracetam, zonisamide, and in some regions imepitoin
• Monitoring blood levels and lab work for medications that require it, especially to balance seizure control with side effects and organ safety
• Emergency treatment for status epilepticus or cluster seizures, which may require hospital care and fast-acting rescue medications directed by a veterinarian
• Avoiding sudden withdrawal of anti-seizure drugs, since abruptly stopping medication can trigger seizures
• Keeping a seizure log with date, duration, what the episode looked like, possible triggers, and recovery behavior
• Lifestyle management such as giving medication consistently, reducing missed doses, and scheduling regular rechecks
• Referral to a veterinary neurologist if seizures are difficult to control, start outside the usual age range, or there is concern for structural brain disease

Veterinarians often consider starting long-term anti-seizure medication when a dog has status epilepticus, cluster seizures, two or more seizure events within 6 months, structural brain disease, or prolonged or severe post-seizure recovery.