What are seizures?
Seizures (also called convulsions or fits) are sudden electrical events that happen in the brain and they cause:
- A change is the patient’s consciousness or awareness of what is going on around them
- Uncontrolled movement of the body
Seizures have many manifestations, but the signs shown by an individual are usually the same each time and will depend on which area of the brain is involved. It is like the same movie being played over and over again! So if your dog or cat is having a seizure and you make a video recording for your vet (a good idea by the way!) then you would only have to do it once because it would look pretty much the same each time the event occurs.
A seizure can last from a few seconds to several minutes and they can involve your dog’s whole body (a Generalised Seizure or ‘Grand Mal’) or just one area of the body (‘Petit Mal’).
What Causes Seizures and Fits?
Seizures can be classified by cause into three categories:
- Those caused by structural brain disorders (such as tumours)
- Those arising from metabolic problems and toxins that affect brain function
- Those in which an underlying disorder cannot be identified. This is known as Idiopathic Epilepsy
Structural brain disorders that can cause seizures include congenital birth defects (such as hydrocephalus), brain tumours, traumatic brain injuries, inflammatory diseases, infections, vascular strokes, and degenerative brain diseases. Metabolic disorders associated with seizures include severe liver and kidney disease, imbalances of blood sodium or calcium, low blood sugar, high blood pressure, and hormonal disorders. A variety of toxins can cause seizures. The age and breed of your dog, neurologic examination findings, and a description of what happened during the seizure are important in determining the underlying cause.
What do seizures look like?
During a generalized (whole body) seizure, the patient will often be unconscious and unresponsive, and may fall or lie down. The legs are often rigidly stretched out or drawn up toward the body. The limbs may jerk or paddle as if the dog is running. Chewing motions, excessive salivation and urination may occur and the patient may have a bowel movement.
During a partial seizure, jerking or twitching movements of a single limb may be seen, the head may turn to one side, or one or both sides of the face may twitch. Repeated blinking of one or both eyes, chewing movements, and salivation may occur. Disorientation, unresponsiveness, excessive barking, unprovoked aggression, or excessive licking or biting at the air (referred to as fly biting) may also occur.
Interestingly, some animals have abnormal behaviour prior to seizures starting – this is referred to as preictal behaviour. Examples include hiding, restlessness and attention seeking. Some owners can actually predict the onset of a seizure based on these behaviours. Some animals also have abnormal behaviour immediately after a seizure, which is referred to as postictal behaviour. Examples include restlessness, panting, increased thirst and looking hunger. Some animals actually become quiet and sleepy. Others can appear blind and bump into objects or seem fearful and growl or bite when approached. This postictal period can last from several minutes to 24 hours.
Animals with brain diseases and metabolic or toxic disorders often have other clinical signs, such as abnormal behaviour or gait, blindness, loss of appetite, vomiting, diarrhoea, excessive thirst, frequent urination, weight loss, weakness, and general debilitation.
What tests are recommended for a dog or cat having seizures?
Evaluation of an animal with seizures includes a general physical examination and health check. Your vet will also perform some tests to make sure certain key parts of the nervous system are working correctly. This is referred to as a neurologic examination. It is very likely that some routine blood tests will be recommended and sometimes x-rays. Additional tests may be recommended based on the results of these tests or if a metabolic or toxic cause is suspected. Identification of specific brain disorders requires imaging of the brain, and an MRI (Magnetic Resonance Imaging) scan may be advised. Sometimes collection and examination of the fluid which surrounds the brain (the cerebrospinal fluid os CSF) will help in the diagnosis of certain inflammations or infections of the brain.
Will my pet get better?
The outlook depends on the underlying cause. It is generally good if the underlying disease can be resolved and less good if it cannot be treated. Outlook for animals with idiopathic epilepsy is usually good because although the condition cannot be cured, many of these seizures can be controlled medically allowing the patient to live a normal life.
The Veterinary Expert| Pet Health
The veterinary expert provides information about important conditions of dogs and cats such as arthrits, hip dysplasia, cruciate disease, diabetes, epilepsy and fits.