The question about why dogs have seizures is a difficult one to answer since no one knows exactly what causes seizures in dogs. A seizure is a complicated condition in which a dog may become rigid, the head may seem as if it is twisted back as if someone is pulling it back and the lips may become contorted over the teeth. The dog may fall on his side as if unconscious, at times. Although the first seizure may lead to panic, feline and canine seizures last only for a couple of minutes and may extend up to five minutes. Only in the severest form of epilepsy known as status epilepticus, do seizures last for hours with without intervals. Extended seizures like these can cause brain damage and can threaten life.
Seizures are considered to be a neurological problem. However, it is also known that seizures can occur due to an underlying disease, genetic predisposition or a low seizure threshold as well. Seizures and epilepsy have become interchangeable terms over the years. Some professionals refer to epilepsy as recurrent seizures that are induced by an unknown cause. At other times, seizures that are unrelated to brain disorders or any other underlying disease are called epileptic seizures.
When the underlying cause of feline or canine seizures is not known, it is commonly classified as primary or idiopathic seizures. Cases where the cause is known are called secondary epilepsy.
Certain dog breeds like the German and Belgian Shepherd Dog (Tervuren), Beagle and Dachshund have a higher suspected predisposition to seizures. Boxers, Cocker Spaniels, Golden, Labrador, Wire-Haired Retrievers and Siberian Huskies are some of the other breeds where the incidence of seizures is higher.
In dogs that are more than the 4 years old the underlying cause is most likely to be found in metabolic diseases like hypoglycemia (low blood pressure), arrhythmia (abnormal rate of musclecontractions in the heart), hypocalcemia (abnormally low level of calcium in the blood; associated with low secretions of parathyroid hormone or kidney malfunction or vitaminD deficiency), brain tumors and cirrhosis (chronic liver disease).
In dogs below one year old, the most common causes of seizure are:
- Developmental disorders like accumulation of cerebrospinal fluid in the ventricles of the brain.
- Toxicity due to lead, arsenic, insecticides that interfere with an insect's nervoussystem or chlorinated hydrocarbons.
- Viral infections like distemper and inflammation of the brain.
- Metabolic disorders like deficiency of metabolic enzymes, liver or kidney disorders.
- Nutritional causes like thiamine efficiency or parasitism.
Genetic causes are often suspected in dogs between the ages of one to three years. Physical trauma, of course, can occur at any age. Head injuries, brain tumors and other types of brain damage caused by cysts can cause undue pressure on different areas in the brain. When this pressure is applied on the areas responsible for balance, consciousness and muscle movements, it can cause the dog to have seizures and accompanying symptoms.
Whatever the cause, the symptoms that a dog shows during a seizure should be noted down carefully and reported to the veterinarian so that a reasonably correct cause may be found.