CANINE - SEIZURES

What is a seizure?

Seizures are one of the most frequently seen neurological problems in dogs. A seizure is also known as a convulsion or a fit. It may have all or a combination of the following:

• Loss or derangement of consciousness

• Contractions of all the muscles in the body

• Changes in mental awareness from non-responsiveness to hallucinations

• Involuntary urination, defecation or salivation

• Behavioural changes, including non-recognition of owner, viciousness, pacing and running in circles 

What are the three phases of a seizure?

Seizures consist of three components:

1. The pre-ictal phase, or aura, is a period of altered behaviour in which the dog may hide, appear nervous, or seek out the owner. It may be restless, nervous, whining, shaking or salivating. This can last from a few seconds to a few hours.

2. The ictal phase is the fit or seizure itself and last from a few seconds to about 5 minutes. During this period, all of the muscles of the body contract strongly. The dog usually falls on its side and seems paralysed while shaking. The head may be drawn backward. Urination, defecation and salivation often occur. If it is not over within 5 minutes the dog may be in a statues epilepticus or going from one seizure into another without respite.

3. During the post-ictal phase there is confusion, disorientation, salivations, pacing, restlessness and/or temporary blindness. There is no direct correlation between the severity of the sizure and the duration of the post-ictal phase. 

Despite the dramatic signs of a seizure your dog will not feel any pain only bewilderment. Dogs do not swallow their tongues however they may bite them or you during the seizure so it is important to keep your hands away from their mouths. The most important thing is to keep your pet from falling or hurting itself, as long as they are lying on the ground there is little chance of harm occurring. If seizures continue for longer than a few minutes or are frequent the body temperature begins to rise this may result in hyperthermia developing secondary to the seizures and must be addressed quickly and effectively.

What causes seizures?

There are many causes of seizures including epilepsy, toxicities or other more extreme cases of diseases such as brain tumours. When a seizure occurs we begin by taking a thorough history concentrating on possible exposure to poisonous or hallucinogenic substances, head trauma and other possible causes. We will also carry out a full physical examination and detailed neurological examination, along with various other tests. These tests rule out possible metabolic causes for brain dysfunction, heart, electrolytes and blood sugar levels. If these tests are normal and there has been no exposure to poison or recent head trauma, further specialist tests including a cerebrospinal fluid examination, MRI or CAT scans may be considered at your veterinary clinic.