How seizures are classified
The International Veterinary Epilepsy Task Force (IVETF) classifies dog seizures into two broad categories based on where in the brain the abnormal activity starts: focal (one hemisphere or region) and generalised (both hemispheres simultaneously).
Focal seizures
A focal seizure originates in a localised area of the brain. Because only part of the brain is involved, the signs are often subtle and easy to miss - particularly early on.
Common signs include:
- Facial twitching or repetitive blinking
- Rhythmic chomping or lip-smacking
- Paddling of one limb
- Episodes of sudden fear, aggression, or unusual vocalisation
- Fly-biting - snapping at invisible objects
A focal seizure may stay localised, or it may evolve into a generalised seizure - this is called focal seizure with secondary generalisation and is common in dogs with idiopathic epilepsy.
Generalised seizures
Generalised seizures involve both sides of the brain from the outset and typically result in loss of consciousness. There are several subtypes:
Tonic-clonic (grand mal)
The most recognisable type. The dog loses consciousness, goes rigid (tonic phase), then experiences rhythmic convulsions (clonic phase). Paddling, urination, defecation, and excessive salivation are common. Most last 1–2 minutes.
Tonic seizures
Sustained muscle rigidity without the rhythmic phase. The dog may fall and remain stiff for several seconds.
Myoclonic seizures
Sudden, brief muscle jerks - often affecting the head and trunk. These can be mistaken for twitching during sleep.
Absence seizures
Rare in dogs. Characterised by a brief “blank stare” and momentary unresponsiveness. Easy to miss entirely.
Atonic seizures
Sudden loss of muscle tone, causing the dog to collapse briefly. Sometimes called “drop attacks.”
The three phases of a seizure
Most seizures - especially tonic-clonic ones - pass through three phases:
- Pre-ictal (aura): Minutes to hours before the seizure, your dog may seem anxious, restless, attention-seeking, or strangely quiet. Not all dogs display this phase.
- Ictal: The seizure itself. Typically 1–3 minutes.
- Post-ictal: The recovery period - ranging from minutes to hours. Your dog may seem confused, disorientated, temporarily blind, or very hungry and thirsty. This is normal and not a cause for alarm in itself.
When is it an emergency?
When to stop reading and pick up the phone
Most seizures are over in a couple of minutes and don’t need an emergency visit. These are the exceptions - call your out-of-hours vet now if any of them are happening:
- Status epilepticus: a single seizure that has been going for more than five minutes, or one that doesn’t stop on its own
- Cluster seizures: a second seizure starting within 24 hours of the first, even if your dog seemed to recover between them
- Your dog hasn’t come round between two seizures
- They’ve been confused, blind, or staggering for more than an hour afterwards
Both status epilepticus and cluster seizures can cause serious harm and need emergency treatment.
What to do during a seizure
- Stay calm - your dog cannot hear or respond to you during the ictal phase
- Do not restrain your dog or put anything in their mouth
- Move sharp or hard objects away to prevent injury
- Start timing immediately - knowing the exact duration is critical for your vet
- Note the time it started and any signs you noticed beforehand
- If you can, record a short video - this is enormously helpful for your vet
The more you know about what you’re seeing, the less frightening it gets. You’re already doing the right thing by reading this.