TL;DR
When an older dog has its first seizure, the cause needs investigating, because new seizures later in life are more often due to something specific, such as a brain tumor, low blood sugar, liver or kidney disease, or a toxin. Still, it is not always bad news: in a study of 99 dogs whose epilepsy started at 5 years or older, 45% of dogs aged 8 to 10 and 39% of dogs aged 11 to 13 turned out to have primary (idiopathic) epilepsy with no structural cause, which is usually manageable with daily medicine. A normal neurological exam did not rule out a brain problem, so specialists recommend MRI for dogs whose seizures start at 5 years or older. Seizures are common overall: 0.82% of UK dogs had at least one in a year, with Pugs at 3.4 times the odds of Labradors and males at higher risk. A seizure that does not stop, or seizures that come one after another, is an emergency.
What does a seizure look like?
| Type | What you might see |
|---|---|
| Generalized (tonic-clonic) | Falling over, stiffening, paddling legs, jaw chomping, drooling, peeing or pooping, not responding |
| Focal | Twitching of the face or one leg, fly-biting, staring, odd repetitive movement, while the dog may stay partly aware |
| Before the seizure | Restlessness, clinginess, hiding, staring |
| After the seizure | Confusion, wobbliness, temporary blindness, pacing, extreme hunger or thirst, which can last minutes to hours |
Things that can look like seizures include fainting from heart disease (usually brief and floppy rather than stiff, often during exercise or excitement), vestibular disease (head tilt and loss of balance with the dog alert) and muscle tremors. A phone video helps your vet tell them apart. See vestibular disease in older dogs, congestive heart failure in dogs and dog muscle spasms.
What to do during a seizure
- Stay calm and time it. Note the start time on your phone.
- Move furniture away, block stairs and keep the dog away from water.
- Do not put your hand near the mouth. Dogs do not swallow their tongue, and a seizing dog can bite without knowing.
- Keep the room quiet and dim.
- Film it if you can, for your vet.
- Stay with your dog afterward, keep it from stairs, and offer water once it is steady.
Go to an emergency vet now if a seizure does not stop within a few minutes, a second seizure starts before your dog has recovered from the first, there are several seizures in a day, or your dog does not return to normal. These are status epilepticus and cluster seizures, which an ACVIM consensus statement describes as emergencies needing early, rapid, stage-based treatment.
Causes of seizures in older dogs
Primary (idiopathic) epilepsy
Epilepsy with no structural cause usually starts in young adults, but the 99-dog study showed it is still common when seizures start later:
| Age when seizures began | Dogs with primary epilepsy |
|---|---|
| 5 to 7 years | 23% (7 of 30) |
| 8 to 10 years | 45% (13 of 29) |
| 11 to 13 years | 39% (13 of 33) |
| 14 years or older | 2 of 7 |
The rest had a cause found on investigation, and brain tumors were less common in the 5 to 7 group than in the older groups.
Brain causes
- Brain tumors, the main concern in older dogs.
- Inflammation of the brain (encephalitis).
- Strokes, which more often cause sudden balance or walking problems but can cause seizures.
Causes outside the brain
- Low blood sugar, for example from an insulin-producing tumor of the pancreas or an insulin overdose in a diabetic dog. See signs of diabetes in dogs.
- Liver disease, which lets toxins reach the brain. See elevated liver enzymes in dogs.
- Kidney failure and severe salt imbalances. See kidney disease in dogs.
- Toxins such as xylitol, some rodent poisons, recreational drugs and certain human medicines.
- Very high blood pressure.
Who is at risk?
In the UK study of 455,553 dogs:
- 0.82% had at least one seizure in a year.
- Pugs had 3.41 times the odds of Labradors.
- Males had higher odds than intact females.
- Dogs weighing 40 kg or more had slightly higher odds than dogs under 10 kg.
See Pug lifespan.
How vets investigate a first seizure in an older dog
- Blood tests: blood sugar, liver and kidney values, electrolytes and sometimes bile acids.
- Blood pressure.
- Neurological exam. In the 99-dog study the exam was abnormal in only 74% of dogs that turned out to have a structural cause, so a normal exam does not rule one out.
- MRI of the brain, with a spinal fluid sample when needed, recommended for all dogs whose seizures start at 5 years or older.
- Chest X-rays or abdominal ultrasound if a tumor elsewhere is suspected.
Treatment
- Treat the cause where one is found: correct blood sugar, treat liver disease, remove a toxin, manage a tumor with surgery, radiotherapy or medicine.
- Daily anti-seizure medicine for epilepsy, such as phenobarbital, imepitoin, levetiracetam or potassium bromide. The goal is fewer, shorter, milder seizures.
- Emergency medicine at home: your vet may give you a rescue medicine to use during a cluster.
- Regular blood tests, because some anti-seizure medicines affect the liver.
Living with a senior dog that has seizures
- Keep a seizure diary: date, time, length, what it looked like and anything unusual beforehand.
- Give medicine at the same times every day. Missed doses are a common trigger.
- Never stop medicine suddenly.
- Make the home safe: gates on stairs, no unsupervised access to pools.
- Watch for side effects such as wobbliness, sleepiness, increased hunger and weight gain. See obesity in dogs.
FAQ
Why would an old dog suddenly start having seizures?
New seizures in older dogs are often caused by a brain tumor, low blood sugar, liver or kidney disease, or a toxin, but many dogs whose seizures start after 5 still have primary epilepsy with no structural cause.
Is a seizure in an older dog an emergency?
A single short seizure with full recovery needs a vet visit within a day. A seizure that does not stop within a few minutes, repeated seizures, or a dog that does not recover is an emergency.
Can old dogs with seizures live a normal life?
Many can, especially dogs with primary epilepsy controlled on daily medicine. The outlook for seizures caused by a brain tumor depends on the tumor and treatment.
Do dogs feel pain during a seizure?
Dogs are generally not conscious during a generalized seizure. Afterward they can be confused, frightened or sore, so keep them quiet and safe.
Which dog breeds have seizures most often?
In a UK study, Pugs had over three times the odds of Labradors, and males and very large dogs had higher odds.
References
- Ghormley TM, Feldman DG, Cook JR Jr. Epilepsy in dogs five years of age and older: 99 cases (2006-2011). Journal of the American Veterinary Medical Association. 2015. PMID: 25632819
- Erlen A, et al. Seizure occurrence in dogs under primary veterinary care in the UK: prevalence and risk factors. Journal of Veterinary Internal Medicine. 2018. PMID: 30216557
- Charalambous M, et al. ACVIM consensus statement on the management of status epilepticus and cluster seizures in dogs and cats. Journal of Veterinary Internal Medicine. 2024. PMID: 37921621
For individual health questions, your veterinarian remains the best partner.
