Understanding Pet Seizures: Causes, First Aid, and When to Act
Watching your pet have a seizure is terrifying. Their body stiffens, they may fall over, paddle their legs, drool, and lose bladder control. Your instinct is to help — but the wrong response can make things worse. Seizures affect an estimated 1--5% of all dogs, making epilepsy one of the most common neurological conditions in canine medicine (Journal of Veterinary Internal Medicine). This guide explains what causes seizures, exactly what to do during one, and when it's an emergency that needs immediate vet care.
What Is a Seizure?
A seizure is a sudden burst of uncontrolled electrical activity in the brain. It causes involuntary muscle movements, altered consciousness, and changes in behaviour. Seizures have three phases:
1. Pre-ictal (aura) — Minutes to hours before. Your pet may seem restless, anxious, clingy, or may hide. Some dogs whine or stare into space.
2. Ictal (the seizure itself) — Typically lasts 30 seconds to 2 minutes. The pet falls, stiffens, paddles legs, may drool, urinate, or defecate. Eyes may be wide and unfocused.
3. Post-ictal (recovery) — Minutes to hours after. Confusion, disorientation, temporary blindness, pacing, excessive thirst or hunger. This is normal and will pass.
Types of Seizures
Generalized (Grand Mal)
The most common and dramatic type. The entire body is involved — stiffening, falling, paddling, loss of consciousness. This is what most people picture when they think "seizure."
Focal (Partial)
Only one part of the body is affected — a single limb twitching, facial tics, or repetitive chewing motions. The pet may remain conscious. Focal seizures can progress to generalized seizures.
Cluster Seizures
Two or more seizures within 24 hours. This is an emergency — cluster seizures tend to escalate and can become status epilepticus.
Status Epilepticus
A seizure lasting longer than 5 minutes, or continuous seizures without recovery between them. This is a life-threatening emergency. Brain damage begins after 5 minutes of continuous seizure activity. Get to an emergency vet immediately.
Common Causes
In Dogs
Idiopathic epilepsy is the most common cause in dogs aged 1–5 years. It's a genetic condition with no underlying brain disease — these dogs are otherwise healthy. Commonly affected breeds include Labrador Retrievers, Golden Retrievers, German Shepherds, Beagles, and Border Collies.
Other causes:
- Toxin ingestion — chocolate, xylitol, cannabis, snail bait, medications
- Liver disease (hepatic encephalopathy)
- Low blood sugar (hypoglycemia) — common in toy breed puppies
- Brain tumours — more common in dogs over age 5
- Infectious disease — distemper, encephalitis
- Head trauma
- Heatstroke
In Cats
Idiopathic epilepsy is rare in cats. A first seizure in a cat is more likely to have a specific underlying cause:
- Toxin exposure — lilies, permethrin (dog flea products), essential oils
- Kidney or liver disease
- Brain tumour or infection
- Feline infectious peritonitis (FIP)
- Hyperthyroidism
- Thiamine (vitamin B1) deficiency — from raw fish diets
Any first seizure in a cat warrants a veterinary workup.
What to Do During a Seizure
Do:
- Stay calm. The seizure looks worse than what your pet feels — they're unconscious during a generalized seizure.
- Time it. Use your phone. Knowing the duration is critical for the vet. A seizure under 2 minutes is usually not life-threatening.
- Clear the area. Move furniture, sharp objects, and other pets away. If your pet is on a bed or couch, gently guide them to the floor if safe to do so.
- Dim lights and reduce noise. Sensory stimulation can prolong seizures.
- Film the seizure if possible. This is the single most useful thing you can show the vet.
- Note what happened before. Were they eating? Playing? Sleeping? Did you recently apply a flea product? Any access to toxins?
Do NOT:
- Do NOT put your hand in their mouth. Pets cannot swallow their tongue. You will get bitten.
- Do NOT restrain them. Holding them down can cause injury to both of you.
- Do NOT pour water on them (unless heatstroke is the suspected cause).
- Do NOT give oral medications during a seizure. They can aspirate (inhale) them.
When Is a Seizure an Emergency?
Go to an emergency vet immediately if:
- The seizure lasts longer than 3 minutes
- Your pet has more than one seizure in 24 hours
- Your pet doesn't return to normal within 1 hour after the seizure
- There was known toxin exposure before the seizure
- It's your pet's first seizure (especially in cats or dogs over age 5)
- Your pet has status epilepticus (continuous seizure or no recovery between seizures)
Use PetEmergency's triage to get an instant assessment and connect with the nearest on-call emergency clinic.
What the Vet Will Do
Immediate stabilization
- IV anti-seizure medication (diazepam, levetiracetam, or phenobarbital) if actively seizing
- Oxygen support
- Temperature monitoring — prolonged seizures cause hyperthermia
Diagnostic workup
- Bloodwork — to check for metabolic causes (liver, kidney, blood sugar, toxins)
- Urinalysis
- Blood pressure
- Neurological exam
- Advanced imaging (MRI, CT) if a brain lesion is suspected — typically at a referral centre
Long-term management
Dogs with idiopathic epilepsy who have frequent seizures (more than 1 per month) are usually started on daily anti-seizure medication — most commonly phenobarbital or levetiracetam (Keppra). These don't cure epilepsy but significantly reduce seizure frequency.
Living with an Epileptic Pet
If your pet is diagnosed with epilepsy:
- Give medication on schedule — missed doses can trigger breakthrough seizures
- Keep a seizure diary — date, time, duration, severity, any triggers
- Avoid known triggers — stress, flashing lights, sudden loud noises, overexertion
- Regular bloodwork — phenobarbital requires monitoring of liver values every 6 months
- Keep your vet informed — report changes in seizure frequency or behaviour
Emergency Resources
If your pet is having a seizure right now:
- Time it
- Keep them safe (clear the area)
- If it exceeds 3 minutes, get to an emergency vet
Start a free triage on PetEmergency.ca — we'll assess urgency and connect you with the nearest on-call clinic.