Epilepsy in Dogs: Diagnosis, Medication, and Long-Term Care

Seeing your dog have a seizure is scary, even when you do everything “right.” The most important thing to know is this: a single seizure does not automatically mean epilepsy. Epilepsy is a chronic condition, often defined as recurrent, unprovoked seizures over time. Many veterinary neurology guidelines use criteria like two or more unprovoked seizures more than 24 hours apart, or one unprovoked seizure with a high risk of recurrence. That difference matters because it changes what your veterinarian will recommend for testing, medication, and long-term monitoring.

As a veterinary assistant, I have watched many families go from shocked and overwhelmed to confident and prepared. With the right plan, most dogs with epilepsy can live happy, active lives.

Epilepsy vs. one seizure

Seizures happen when there is abnormal electrical activity in the brain. The “why” can vary widely, especially after a first event.

When it may be one-time or situational

• Toxin exposure (certain human medications, illegal substances, insecticides, toxic plants, and more)
• Metabolic issues like low blood sugar, liver disease, kidney disease, or electrolyte imbalances
• Xylitol exposure: can trigger dangerous hypoglycemia and liver injury, and seizures may occur secondary to low blood sugar
• Heat stroke
• Severe illness or certain infections and inflammatory conditions

When it may be epilepsy

Epilepsy is most commonly discussed as:

• Idiopathic epilepsy: recurrent seizures with no structural brain disease identified. Often suspected in dogs roughly 6 months to 6 years, especially if the neurologic exam is normal between seizures.
• Structural epilepsy: seizures caused by a problem in the brain such as a tumor, stroke, inflammation, or a congenital abnormality.

If your dog has had two or more seizures that are not clearly triggered by something we can correct, it is time to talk with your vet about an epilepsy workup and whether medication is appropriate.

Seizure or something else?

Not every “episode” is a seizure. Two common look-alikes are:

• Syncope (fainting): often sudden collapse with quick recovery. Some dogs look weak or limp more than stiff, and it may be tied to exertion, excitement, coughing, or heart disease.
• Vestibular events: head tilt, loss of balance, falling to one side, and rapid eye movements. These can look dramatic, but they are not typically true seizures.

If you are unsure, a video and a detailed description are incredibly helpful. Many owners accurately sense “something isn’t right,” even if they cannot label it.

What a seizure can look like

Not all seizures look like the classic generalized tonic-clonic event (“grand mal”). Some are subtle, and owners often describe them as “something just felt off.”

Common phases

• Pre-ictal (before): pacing, anxiety, clinginess, hiding, restlessness
• Ictal (during): collapse, paddling, jaw chomping, drooling, loss of bladder or bowel control, or brief staring and facial twitching
  Safety warning: Do not put your hands in your dog’s mouth. Dogs do not swallow their tongues, and you risk a severe accidental bite.
• Post-ictal (after): disorientation, temporary blindness, hunger, thirst, wobbliness, sleepiness

Tip: video can be incredibly helpful. If it is safe, record part of the event and time it. Duration and recovery time help your veterinarian make better decisions.

What to do during a seizure

In the moment, your job is safety and information. Try to:

• Stay calm and time it (use your phone timer)
• Keep your dog safe: move furniture away, block stairs, and cushion the head if you can do so without getting near the mouth
• Make it quiet and dim: reduce noise, turn off bright lights, keep other pets and children away
• Do not restrain your dog and do not offer food or water until fully alert
• Afterward, keep them in a safe, enclosed area while they recover (many dogs are wobbly or temporarily “not themselves”)

If your vet has prescribed rescue medication, follow your written seizure plan exactly and call the clinic or ER for next steps.

How vets diagnose epilepsy

There is not one single “epilepsy test.” Diagnosis is usually a combination of history, pattern recognition, and ruling out other causes.

Step 1: History and seizure log

Expect questions about your dog’s age at first seizure, frequency, duration, recovery, triggers, diet changes, medications, and possible toxin exposure.

Step 2: Physical and neurologic exam

A normal neurologic exam between seizures often supports idiopathic epilepsy, though it does not prove it. New seizures in a very young dog or a senior dog, or an abnormal neurologic exam, raise concern for metabolic or structural causes.

Step 3: Baseline lab work

• Bloodwork (CBC and chemistry) to check liver, kidneys, glucose, electrolytes
• Urinalysis to evaluate systemic health
• Additional tests depending on the dog: bile acids, infectious disease testing, blood pressure, toxin screening

Step 4: Advanced diagnostics when needed

• MRI to look for structural brain disease
• CSF tap (cerebrospinal fluid) to evaluate for inflammation or infection

Your vet may recommend a referral to a veterinary neurologist, especially for very young dogs, senior dogs with new seizures, dogs with abnormal neurologic exams, or dogs that are difficult to control on medication.

When daily meds are needed

Many dogs are not started on daily anti-seizure medication after a single seizure, especially if a trigger is identified and corrected. Long-term medication is more likely recommended when the risk of future seizures is high or the seizures are severe.

Common reasons to start

• Two or more seizures, especially if they are increasing in frequency
• Cluster seizures (two or more seizures within 24 hours)
• Status epilepticus (often defined as a seizure lasting 5 minutes or repeated seizures without full recovery)
• Seizures that are prolonged, violent, or have a difficult recovery phase

Goals are usually to reduce frequency and severity, not always to eliminate seizures entirely. That is a hard truth, but it helps set realistic expectations and avoid constant medication changes that can create side effects without better control.

Common epilepsy meds

Your veterinarian will tailor medication choices based on seizure control, your dog’s overall health, lifestyle, and budget. Some dogs do well on one medication, while others need a combination.

Phenobarbital

Phenobarbital is one of the most commonly used long-term anti-seizure medications in dogs and is often effective, especially for idiopathic epilepsy.

• Common side effects early on: sleepiness, wobbly walking, increased hunger and thirst
• Long-term considerations: can elevate liver enzymes and, rarely, cause liver injury, so regular monitoring is important
• Consistency matters: dosing needs to be very consistent, and you should not stop it suddenly

Levetiracetam (Keppra)

Levetiracetam is commonly used for epilepsy and is often chosen when a wide safety margin is a priority. Some dogs take it as a primary medication, and many take it as an add-on.

• Common side effects: mild sleepiness, occasional GI upset, and behavior changes in some dogs (usually occasional)
• Practical note: it is often given multiple times per day, though extended-release forms may be an option for some dogs

Zonisamide

Zonisamide is another commonly prescribed anti-seizure medication in modern veterinary medicine. It may be used as a primary medication in some dogs, but it is very commonly used as an add-on when one medication is not enough.

• Common side effects: sleepiness, decreased appetite, GI upset
• Notes: your vet may recommend periodic lab monitoring depending on your dog’s health history and the full medication plan

Potassium bromide

Potassium bromide is often used as an add-on medication, especially when seizures are not fully controlled by phenobarbital alone, or when phenobarbital is not a good fit.

• Common side effects: sedation, wobbliness, nausea, increased thirst and appetite
• Diet matters: changes in dietary salt can change bromide levels. Try to keep diet consistent and talk to your vet before switching foods.
• Takes time: it can take weeks to months to reach steady levels, so it is not a quick fix
• Extra caution: may not be ideal for some dogs with kidney disease, and your vet will weigh risks and benefits

Rescue meds at home

For dogs with cluster seizures, your veterinarian may prescribe a rescue plan for home use. This often includes a benzodiazepine (like diazepam or midazolam) given in a way your vet instructs, such as intranasal or rectal administration. The goal is to stop a seizure cycle early and avoid an ER visit.

Never use human medications or leftover prescriptions unless your veterinarian specifically directs you. Dosing and safety are very different for dogs.

Side effects to watch for

Most side effects are most noticeable in the first days to weeks after starting or changing a dose. Many dogs adjust well, but you should keep your vet updated.

Call your vet promptly if you notice

• Severe sedation, collapse, or inability to walk normally
• Vomiting that does not resolve, refusal to eat, or persistent diarrhea
• New or worsening behavior changes
• Yellow gums or eyes, pot-bellied appearance, or unusual bruising
• A sudden jump in seizure frequency or intensity

Important: Do not stop seizure medication suddenly unless a veterinarian tells you to. Abrupt withdrawal can trigger serious rebound seizures.

Monitoring and rechecks

Long-term management is not only about giving a pill. It is a partnership between you and your vet, using symptoms and lab monitoring to keep seizures controlled and organs healthy.

Common monitoring tools

• Seizure diary: date, time, duration, description, recovery time, possible trigger, and whether rescue meds were used
• Phenobarbital blood levels: helps confirm the dose is in a therapeutic range (often rechecked after the medication has had time to reach a steady level, then periodically)
• Potassium bromide levels: especially after dose changes and periodically long-term
• Routine chemistry panels: especially liver values with phenobarbital, and overall health monitoring for any epilepsy patient

Your veterinarian will set the schedule, but monitoring is often more frequent at the beginning and then moves to routine rechecks once your dog is stable.

Lifestyle tips that help

Medication is the foundation for many dogs, but daily routines can make a meaningful difference in seizure control and quality of life.

Keep routines steady

• Give medication at the same times every day
• Prioritize consistent sleep and predictable schedules
• Avoid sudden diet changes, especially for dogs on potassium bromide

Reduce triggers when possible

Not every dog has clear triggers, but some owners notice patterns such as stress, excitement, sleep deprivation, or certain environments. If you see a pattern, share it with your vet.

Discuss flea and tick products

If your dog has epilepsy or suspected epilepsy, ask your veterinarian which flea and tick preventatives are safest. Some products, including the isoxazoline class, may lower the seizure threshold in certain dogs, and many veterinarians avoid them in seizure patients unless the benefits clearly outweigh the risks.

Plan for safety

• Use baby gates near stairs if your dog is unsteady post-seizure
• Supervise near pools and bodies of water
• Consider padded bedding for dogs who seize during sleep

Nutrition and body condition

Keeping your dog at a healthy weight supports overall wellness and makes medication dosing more predictable. If you are interested in homemade food, work with your veterinarian or a board-certified veterinary nutritionist to ensure the diet is balanced, especially for a dog on long-term medication.

Emergency red flags

Even with a long-term plan, some seizure situations are emergencies. Seek urgent veterinary care if:

• A seizure lasts 5 minutes or longer
• Your dog has cluster seizures (two or more seizures in 24 hours)
• Your dog has trouble breathing, does not wake up normally, or seems dangerously overheated
• This is the first seizure your dog has ever had, especially if your dog is very young or older

If your veterinarian has prescribed rescue meds, follow your written seizure plan and then call the clinic or ER for next steps.

Long-term outlook

Many dogs with idiopathic epilepsy can do very well long-term, especially with consistent medication and monitoring. Some dogs achieve excellent control with rare breakthrough seizures. Others need medication adjustments over time, and a smaller group will have challenging epilepsy that requires a neurologist and multi-drug protocols.

What matters most is your dog’s day-to-day quality of life. With a clear plan, good communication with your veterinary team, and realistic expectations, you can replace fear with confidence.

If you remember just one thing, let it be this: managing canine epilepsy is a marathon, not a sprint. Consistency, monitoring, and teamwork are where the wins happen.

Quick at-home checklist

• Start a seizure diary and bring it to every visit
• Take videos when safe and note the length of the event
• During a seizure: time it, clear hazards, keep hands away from the mouth
• Give medications on schedule and never stop abruptly
• Ask your vet if your dog needs rescue medication at home
• Schedule recommended bloodwork and drug level checks
• Keep diet and routine consistent, especially if potassium bromide is used
• Confirm the safest flea and tick prevention plan for a seizure-prone dog