SIGNS OF CANINE EPILEPSY

Epileptic seizures are a result of abnormal and excessive electrical activity in the brain. Canine epilepsy can manifest itself in many ways, depending on the location and strength of the abnormal electrical signals in the brain.

Typical signs you may see in a pet experiencing an epileptic seizure include;

• Loss of consciousness
• Twitching & involuntary movements
• Rigid legs initially, then paddling or running movements
• Urination or defaecation
• Salivation and mouth “chomping”

Seizures usually abruptly start and finish, although you may notice your dog behaves differently before and after a seizure.

What to expect, before, during and after a seizure

Pre-ictal phase (Before a seizure begins)

You may notice that your pet behaves differently before a seizure, this period of behaviour change is known as the ‘pre-ictal phase’. This phase can last anything from a few hours to a few days and will vary between individuals. Some pets may not exhibit obvious behavioural changes during this time, others may seem more anxious, nervous, agitated, clingy, aggressive or more reserved (hide away).

Ictus/Ictal (During a seizure)

Ictus is the second phase and corresponds to the seizure itself. It is when the excessive abnormal electrical activity occurs in the brain, which results in the signs that are seen during the seizure (such as involuntary movement). The ictal phase is usually very brief, lasting less than 2 minutes.

Postictal phase (After a seizure)

The final stage of a seizure, the postictal phase, is when the brain recovers its normal function after the seizure.

During this phase, dogs may be tired and confused. They may also be disoriented, anxious or even aggressive.
Your pet may also be; hungry, thirsty, and wobbly. Very rarely, some pets experience temporary blindness. Some dogs will not experience any post-ictal signs and they will quickly be back to normal following a seizure. For dogs that do experience post-ictal signs, they are usually transient and resolve within a few minutes to a few days.

Different types of Epileptic seizure

The clinical signs of epilepsy vary between individuals. Generally speaking, there are two main types of seizure.

Generalised seizures

Generalised epileptic seizures are due to abnormal electrical activity affecting the whole of the brain, and the signs therefore occur across the whole body.  Generalised seizures can occur because of idiopathic epilepsy, structural epilepsy (a problem in the brain) and reactive seizures (e.g. toxins).

The seizures are usually short-lived, lasting from a few seconds to a few minutes (usually less than 2–3 minutes), but may seem much longer.

A seizure generally begins with a complete loss of consciousness, and the animal lies on its side. This is then followed by intense movements on both sides during which, the animal pedals/paddles its legs and often and chews or grinds its jaws.

This may be accompanied by increased salivation (drooling), urination, defaecation, dilated pupils and irregular or disrupted breathing.

Not all these signs are seen every time and the signs exhibited during a seizure will vary between individuals.

Partial/focal seizures

Partial/focal seizures are the result of a localised part of the brain experiencing abnormal electrical activity. One or more areas of the brain may be affected. Depending on the brain regions involved, the seizures may affect movement, behaviour and/or bladder/bowel function. In general, these seizures last a few minutes.

Partial/focal seizures can occur in dogs with idiopathic epilepsy but are generally rarer than the generalised form. Studies report that they are more common in certain (Poodles, English Springer Spaniels) (see What Dogs are Affected?). They occur more frequently in cats (see What does an epileptic seizure look like in cats?) than in dogs.

This type of seizure can also be seen with structural epilepsy caused by localised damage in the brain (e.g. tumour, trauma, stroke).

The signs seen depend on the area of the brain affected and can include: altered consciousness or loss of attention (e.g., staring into space), muscle movement (jerking one or more limbs, craning neck, chewing, facial spasms etc.), excessive salivation, dilated pupils, tremors and behavioural changes (chasing imaginary flies, vocalisation, howling, running aimlessly or chasing their tail etc.).

These focal seizures are often less obvious than generalised epileptic seizures and owners may not even realise they have occurred.
Dogs will often recover spontaneously, but the seizures can progress to the generalised form.

Status epilepticus (seizures lasting in excess of five minutes)

Status epilepticus is defined as seizure that lasts longer than 5 minutes or when two or more seizures occur without complete recovery of consciousness in-between. It can be a life-threatening emergency and the animal should be taken immediately to a vet for treatment. Status epilepticus can occur with any type of epilepsy and appears to be more common in dogs with structural epilepsy and reactive seizures.