My Old Dog Just Had a Seizure — A Vet Explains What Happened and What to Do Next

It happens without warning. Your dog is lying quietly, or walking across the room, or sleeping beside you — and then suddenly they collapse. Their legs are paddling, their jaw is chomping, their whole body is shaking. You freeze. You do not know whether to touch them, hold them, call someone, or just stand there and scream.

If this has just happened to your dog, I want you to know: you are not alone, and the fear you feel right now is completely normal. Watching your dog have a seizure is one of the most traumatic things a pet owner can experience.

And if your dog is a senior — eight, ten, twelve years old — and this is the first time this has ever happened, I also need to tell you something important: a first seizure in an older dog means something different from a seizure in a young dog. It is not the same situation, it does not have the same causes, and it needs to be taken seriously and investigated properly.

In this guide I am going to explain exactly what is happening when a dog has a seizure, why senior dogs are more vulnerable, what the most likely causes are in older dogs specifically, what to do while it is happening, and what the diagnosis and treatment process looks like. I will also tell you honestly when a seizure is an emergency and when it is not.

What Actually Happens During a Seizure

A seizure is an abnormal, uncontrolled electrical discharge in the brain. For a brief period, the normal signals that control movement, consciousness, and body function are completely overwhelmed by this electrical storm — and the dog's body responds with the symptoms we see.

Seizures in dogs have three distinct phases, and understanding them will help you stay calm and give your vet the information they need.

The pre-ictal phase — before the seizure

In the minutes or sometimes hours before a seizure, many dogs show subtle behavioural changes. They may seem anxious, clingy, or unusually restless. Some dogs pace, whine, or seek out their owner in an uncharacteristic way. Others stare blankly. This is the dog sensing, at some level, that something is wrong. If you notice this pattern repeating before future seizures, it gives you valuable warning time.

The ictal phase — the seizure itself

This is the phase most people think of when they hear the word seizure. In a grand mal (generalised) seizure — the most common type — the dog collapses suddenly, loses consciousness, and the whole body goes rigid and then jerks violently. The legs paddle, the jaw chomps, saliva drools from the mouth, and the dog may urinate or defecate without control. This is terrifying to watch but usually lasts only one to three minutes, though every second feels much longer.

Not all seizures look like this. Focal seizures affect only one part of the body — one leg twitching, the face muscles flickering on one side, repeated blinking. These can be easy to miss or dismiss as something else. They matter just as much and deserve the same investigation.

The post-ictal phase — after the seizure

After the main seizure ends, dogs do not immediately return to normal. The post-ictal phase can last anywhere from a few minutes to several hours. During this time your dog may be confused, disoriented, or temporarily blind. They may walk in circles, seem unable to recognise you, or simply stand and stare. They are often exhausted and want to sleep. This is normal — the brain has just undergone enormous stress and needs time to recover. Do not be alarmed if your dog seems like a different animal in the hour after a seizure. They will come back to themselves.

Why Senior Dogs Are More Likely to Have Seizures — and Why It Is Different

Here is what I need every owner of an older dog to understand: when a young dog between six months and six years has their first seizure, the most likely cause is idiopathic epilepsy — a genetic condition where the brain simply has a faulty electrical threshold. No underlying disease, no tumour, no organ failure. Just the brain misfiring.

When a dog over six or seven years old has their first seizure, that changes completely. According to Cornell University College of Veterinary Medicine, dogs that are over six years old when they have their first seizure are more likely to have a metabolic disorder or a structural brain lesion, such as a tumour or a stroke. Idiopathic epilepsy in a dog showing seizures for the first time at age ten is unlikely. Something has changed in that dog's body — and we need to find out what.

This is why I always tell owners of senior dogs: do not assume this is "just epilepsy." Do not Google the condition, read about dogs who manage fine on medication, and conclude your dog is the same. Get your dog properly investigated first.

The Most Common Causes of Seizures in Senior Dogs

Kidney disease

As the kidneys fail, they lose their ability to filter waste products from the blood. Toxins — particularly urea and other nitrogenous compounds — accumulate in the bloodstream. When these reach the brain, they can trigger seizures. This is called uraemic encephalopathy. It is one of the most common causes of new-onset seizures I see in older dogs, and it is one of the reasons a blood test is essential after any first seizure in a senior dog. Kidney disease is also treatable and manageable — especially when caught early.

Liver disease

The liver processes ammonia produced by the gut. When liver function deteriorates, ammonia builds up in the blood and crosses into the brain — a condition called hepatic encephalopathy. This can cause seizures, confusion, and erratic behaviour. Certain medications, infections, and age-related liver changes can all contribute to this in older dogs.

Diabetes and low blood sugar (hypoglycaemia)

Senior dogs with diabetes mellitus are at risk of hypoglycaemia — dangerously low blood sugar — particularly if they receive insulin and then do not eat, or receive too high a dose. When blood sugar drops low enough, the brain — which runs entirely on glucose — begins to malfunction, and seizures result. Dogs with an insulin-secreting tumour called an insulinoma can also develop hypoglycaemia, and this is worth ruling out in any senior dog with unexplained seizures.

Brain tumours

This is often the first thing owners fear when they see a first seizure in an older dog — and while I wish I could tell you it is not a concern, brain tumours are a significant cause of new-onset seizures in senior dogs. As dogs age, the risk of tumours — both primary brain tumours and tumours that have spread from elsewhere in the body — increases. A tumour pressing on brain tissue disrupts the electrical activity in that area and can trigger seizures. MRI is the only way to image the brain directly and confirm or rule out this cause.

Stroke

Strokes in dogs — caused by either a blood clot blocking flow to the brain, or a bleed within brain tissue — can cause sudden neurological signs including seizures. Senior dogs with underlying heart disease, high blood pressure, kidney disease, or Cushing's disease are at increased risk. A stroke is usually a sudden event, and signs other than seizures — sudden loss of balance, head tilt, circling, one-sided weakness — are often present at the same time.

Cushing's Disease (Hyperadrenocorticism)

Cushing's disease causes the adrenal glands to overproduce cortisol. Beyond the classic signs of increased thirst, pot belly, and hair loss, Cushing's disease can affect blood pressure and metabolism in ways that make seizures more likely. It is also one of the conditions that can cause hypertension — high blood pressure — which in turn stresses the brain.

Toxin ingestion

Dogs who have eaten something toxic — chocolate, xylitol (found in sugar-free products), certain rat poisons, human medications, or garden chemicals — can develop seizures rapidly. If your dog has had access to anything unusual in the hours before the seizure, tell your vet immediately. Some toxins are treatable if caught quickly.

What to Do While Your Dog Is Having a Seizure

I know this feels impossible in the moment, but these steps protect your dog and give your vet the best information to work with.

Stay calm

Your dog cannot hear or respond to you during the seizure, but they can sense your panic in the post-ictal phase. Stay as composed as you can. Most seizures end on their own within one to three minutes.

Do not put anything in your dog's mouth

Dogs cannot swallow their tongues during a seizure — this is a myth. Putting your hands or any object near their mouth while they are seizing will result in a bite, and not because your dog means to hurt you. Their jaw is clamping involuntarily. Keep your hands away from the mouth.

Move hazards away, not your dog

If your dog is near stairs, a table with sharp edges, or anything that could fall on them, move those objects — or gently guide your dog away from them if they are close to the edge of something. Try not to restrain or hold the dog down. The convulsions need to move through the body.

Time the seizure

Look at a clock the moment you realise what is happening and note when it ends. Your vet will ask you how long it lasted. This information directly affects how urgently you need to act.

Record it if you safely can

I cannot tell you how many times a video on a phone has helped me diagnose a dog faster. If someone else is with you, ask them to film. If you are alone, get the dog safe first and film if you can. The difference between a generalised grand mal and a focal seizure can look very different on a recording, and it changes what tests I order.

Keep the room dim and quiet during recovery

After the seizure ends, dim the lights, reduce noise, and let your dog recover without being overwhelmed by stimulation. Speak softly. Do not crowd them. Offer water once they are oriented enough to drink safely.

When Is a Seizure an Emergency — and When Should You Go Immediately?

This matters. Not every seizure requires a midnight emergency clinic visit — but some absolutely do. Here is how I think about it.

Go to an emergency vet immediately if:

• The seizure lasts more than five minutes without stopping — this is called status epilepticus and is a life-threatening emergency. The brain cannot sustain this level of electrical activity without damage.

• Your dog has more than two seizures within 24 hours (cluster seizures).

• Your dog does not regain consciousness or awareness between seizures.

• Your dog is having obvious difficulty breathing during or after the seizure.

• You know or suspect your dog has eaten something toxic.

• Your dog was diagnosed with diabetes and you suspect low blood sugar.

Call your vet first thing the next morning if:

• It was a single seizure that lasted less than five minutes and your dog is recovering normally.

• This is your dog's first ever seizure and they are a senior.

• Your dog has had occasional seizures before but this one was different in some way.

Never wait-and-see after a first seizure in a senior dog without speaking to a vet. Even if your dog seems completely fine the next morning, the underlying cause needs to be investigated.

How a Vet Diagnoses the Cause of Seizures in a Senior Dog

When you bring your dog in after a seizure, your vet's job is to answer one question: why did this happen? The investigation usually follows a structured path.

Full clinical history

Your vet will want to know everything: exactly what the seizure looked like, how long it lasted, what happened before and after, whether this has happened before, what medications your dog is on, and whether they could have eaten anything unusual. The more details you can provide — especially a video — the faster we can narrow down the cause.

Blood and urine tests

This is the essential first step for any senior dog with new-onset seizures. A full biochemistry panel checks kidney function, liver function, blood glucose, electrolytes, and other markers. This rules out — or confirms — metabolic causes like kidney disease, liver disease, diabetes, and electrolyte imbalances. A urinalysis adds further information. These tests are relatively quick and affordable and can answer a lot of questions in a single visit.

Blood pressure measurement

High blood pressure is an under-recognised cause of seizures in older dogs. It is also a consequence of kidney disease, Cushing's disease, and hyperthyroidism — all more common in seniors. Measuring blood pressure is simple and non-invasive, and should be part of any senior dog seizure workup.

MRI of the brain

If blood tests and blood pressure come back normal, or if the clinical signs strongly suggest a brain lesion, an MRI is the next step. This is the only way to directly visualise the brain and identify a tumour, a stroke lesion, or inflammation. MRI requires general anaesthesia, which carries additional risk in older dogs — your vet will assess whether the benefit of the information outweighs that risk in your dog's specific situation.

Cerebrospinal fluid analysis

In some cases, a sample of cerebrospinal fluid (the fluid that surrounds the brain and spinal cord) is taken and analysed to look for infection or inflammation of the brain. This is usually done at the same time as an MRI, under the same anaesthetic.

Treatment Options for Seizures in Senior Dogs

Treating the underlying cause

If the seizures are caused by kidney disease, liver disease, diabetes, or Cushing's disease, treating that underlying condition is the priority. When the metabolic problem is controlled, the seizures often improve significantly or stop entirely. This is one of the most important reasons to investigate rather than simply starting anti-seizure medication in every senior dog who seizes.

Anti-seizure medication

When seizures are frequent, severe, or caused by a primary brain condition, medication is used to reduce their frequency and severity. According to the Merck Veterinary Manual and the ACVIM consensus guidelines, phenobarbital and potassium bromide are the established first-line anticonvulsant medications in dogs. Phenobarbital is the most widely used — it is effective, affordable, and well-tolerated in most dogs. It does require regular blood monitoring, because long-term use can affect the liver. Newer options including levetiracetam and zonisamide are also used, particularly in dogs who do not respond well to phenobarbital or who have liver concerns.

An important reality about seizure medication: it does not usually stop seizures completely. The goal is to reduce their frequency to a manageable level and make them less severe. Owners need to know that going from monthly seizures to one every three months is a genuine treatment success — not a failure.

Management of brain tumours

If a brain tumour is identified, the options depend on the tumour type, location, and your dog's overall health. Anti-seizure medication to control the fits is usually the immediate priority. From there, options include radiation therapy (which is available at specialist centres and can extend quality life significantly for certain tumour types), palliative corticosteroids to reduce swelling around the tumour, or, in some cases, surgery. These are specialist conversations, and referral to a veterinary neurologist is appropriate.

What You Can Do at Home

Living with a dog who has seizures requires some practical adjustments to keep them safe.

Keep a seizure diary

Note every seizure: date, time, duration, what it looked like, how long recovery took, what your dog ate that day, any unusual activity or stress. This diary is invaluable for your vet. It helps identify triggers, track whether medication is working, and detect patterns that could indicate a change in the underlying condition.

Remove hazards from your dog's environment

If your dog has had more than one seizure, think about where they spend most of their time. Avoid unsupervised access to stairs, raised decks, or swimming pools. A dog mid-seizure near a pool or at the top of a staircase can sustain a serious injury. Baby gates and closed doors are inexpensive and effective solutions.

Never leave a seizing dog unsupervised near water

Even a shallow water bowl can be a drowning risk during a prolonged seizure. Raise water bowls to a height that prevents the dog's head from going under if they collapse nearby.

Know your emergency plan before you need it

Find out where your nearest 24-hour emergency vet is before your dog has another seizure. Have their number saved in your phone. Know your dog's weight and current medications so you can tell the vet immediately when you arrive. Being prepared means you are not panicking and searching the internet at 2am while your dog is seizing on the kitchen floor.

A Final Word from Dr. Waleed

I know how frightening it is to watch your dog have a seizure. The helplessness of standing there, not knowing what to do, not knowing if they are going to be okay — it is one of the hardest things you can experience as a dog owner.

But here is what I want you to hold onto: seizures in senior dogs, while serious, are often the first sign of something that can be treated. A dog who seizes because of kidney disease can have that disease managed. A dog who seizes because of low blood sugar can have their insulin adjusted. A dog who seizes because of a brain condition can often have those seizures controlled with medication and live a good quality of life for many more months.

What matters most is not panicking, getting your dog to a vet, and getting the right tests done. The cause matters. The cause determines everything that comes next.

Your dog needs a diagnosis, not just a prescription. Please give them that.

Frequently Asked Questions

My old dog just had a seizure for the first time ever — should I go to the emergency vet tonight or wait until morning?

If the seizure lasted less than five minutes and your dog has now recovered — eating, drinking, walking, and recognising you — it is generally safe to call your vet first thing in the morning rather than going to an emergency clinic overnight. However, if the seizure lasted more than five minutes, if your dog had more than one seizure in the same day, if they are not recovering normally, or if you suspect they ate something toxic, go to an emergency vet tonight. Do not wait. And regardless — a first seizure in a senior dog always needs a proper vet workup. Do not assume it is a one-off and never have it investigated.

My dog is 11 years old and just had his first seizure — what is most likely causing it at his age?

In an older dog, the most likely causes of a first seizure are kidney disease, liver disease, a brain tumour, a stroke, diabetes or low blood sugar, or Cushing's disease. Idiopathic epilepsy — the type common in young dogs with no identifiable cause — is unlikely to appear for the first time at age 11. This is exactly why blood tests, urine tests, and blood pressure measurement are essential after a first seizure in a senior dog. These tests rule in or out the most common causes quickly and affordably.

What does a dog seizure look like — how do I know if that is what happened?

A classic grand mal seizure involves sudden collapse, loss of consciousness, body going rigid then jerking violently, legs paddling, jaw chomping, drooling, and sometimes urination or defecation. It usually lasts one to three minutes. After it ends, the dog will be confused, disoriented, possibly temporarily blind, and very tired — this is the post-ictal phase and can last from minutes to hours. Not all seizures look this dramatic — focal seizures may involve just one leg twitching, the face flickering, or the dog staring blankly and smacking their lips. If you are not sure whether what you saw was a seizure, describe it to your vet in detail and show them a video if you have one.

How long is too long for a dog seizure?

Any seizure lasting more than five minutes is a medical emergency called status epilepticus and requires immediate veterinary attention. The brain cannot sustain that level of abnormal electrical activity without damage occurring. Do not wait for it to stop on its own. Go to an emergency vet now. Also treat it as an emergency if your dog has two or more seizures within 24 hours even if each individual seizure was brief — this is called cluster seizures and is equally serious.

Will my senior dog need to be on anti-seizure medication for the rest of his life?

It depends on the cause. If the seizures are caused by a treatable metabolic condition — kidney disease, diabetes, liver disease — managing that underlying condition is the priority, and anti-seizure medication may not be needed long-term once the metabolic problem is controlled. If the cause is a primary brain condition like a tumour, or if no underlying cause can be found, long-term anticonvulsant medication is usually recommended. Your vet will guide you on when to start medication and what drug to use based on your dog's specific situation and bloodwork results.

Can a dog die from a seizure?

A single, brief seizure that resolves on its own is very unlikely to be fatal directly. However, status epilepticus — a seizure lasting more than five minutes — can be life-threatening because of the sustained stress on the brain and the risk of overheating. Additionally, if a dog seizes near stairs, water, or heavy furniture, they can sustain a serious physical injury. The underlying cause of the seizures — such as advanced kidney failure or a large brain tumour — can of course be life-limiting. This is why investigating the cause matters so much. The seizure itself is often not what is most dangerous — it is what is causing the seizure.

My dog had a seizure and now seems completely fine — do I still need to see a vet?

Yes, absolutely. The post-ictal recovery period can make a dog seem completely normal within hours of a serious seizure, especially if it was their first. But the underlying cause has not gone anywhere. A dog who seemed perfectly fine after their first seizure but was not investigated is a dog whose kidney disease, brain tumour, or liver condition continued to progress untreated. Please see your vet. The fact that your dog seems okay now is good news — it means you have time to get the right tests done without panic. Use that time.

Is it safe to have an older dog with seizures under general anaesthesia for tests like MRI?

This is a fair concern and one your vet will take seriously. Senior dogs do carry a higher anaesthetic risk than young, healthy dogs — but modern anaesthetic protocols, careful pre-anaesthetic blood screening, and appropriate monitoring make it far safer than many owners fear. The decision to pursue MRI under anaesthesia is always weighed against the value of the information it provides. In many cases, knowing whether a brain tumour is present fundamentally changes the treatment plan and quality-of-life conversation — and that information is worth the risk. Your vet will be honest with you about your specific dog's risk based on their health status.

Ask Dr. Waleed

Have a question about your senior dog's health? Send it to Dr. Waleed directly — I read every message and answer as many as I can.