What Are the Causes of Seizures & Irregular Hearth Rhythm in Dogs?

Seizures and irregular heartbeat are both scary conditions that occasionally occur together. Although both conditions share some possible underlying causes, they can be caused by a wide range of possibilities. Seizures and irregular heart rhythm can both be signs of a serious illness, injury or poisoning. However, sometimes both the causes and the symptoms are manageable, and your dog can lead a long and normal life.

Seizures happen when an electrical storm occurs in the frontal and temporal lobes of the brain. When this electrical activity remains confined to a specific location, it causes a partial, or focal, seizure that causes involuntary motor movement in only one part of the body, and can sometimes also cause inexplicable changes in behavior. When the electrical activity spreads through the brain, a generalized seizure affecting the entire body occurs. This can be relatively mild, in which the dog remains conscious and aware, or it can be a grand mal seizure, during which the dog loses consciousness or awareness as his body seizes and goes rigid. This is followed by involuntary movements such as foot paddling or chewing.

An irregular heartbeat is called an arrhythmia. Arrhythmias are caused by abnormal electrical activity in the heart that affect the frequency, strength and regularity of the heartbeats. They can be a sign of heart disease or other illness, but there are a number of possible causes, and some dogs are able to live normal lives for years without showing any sign of their heartbeat irregularities. Arrhythmias caused by serious heart conditions can cause fainting, which is sometimes mistaken for a seizure, according to the Long Beach Animal Hospital website.

The electrical activity in the brain that causes seizures can itself have a number of different causes, though often the cause is unknown. Seizures of unknown cause are referred to as idiopathic seizures; if they occur on an ongoing basis, your dog will be considered to have epilepsy. This is the most common type of seizure, according to Long Beach Animal Hospital, and it is often genetic among purebred dogs, with several breeds being prone to epilepsy. Seizures with an identifiable cause are generally referred to as secondary. Causes of secondary seizures include poisoning, brain trauma, hydrocephalus, tumors, stroke, low blood sugar, parasites and various illnesses such as hypothyroidism, liver disease or kidney disease. Viruses such as rabies and distemper can also cause seizures.

Like seizures, the abnormal electrical activity responsible for heart arrhythmias can have a number of causes, including genetic, with some breeds predisposed to them. Arrhythmias can also be congenital, meaning that they’re present from birth. They can also be caused by environmental stress, poisoning, infections and heart disease, among other possibilities. With so many possible causes, it’s important to have your dog seen by a vet if you have any reason to suspect an irregular heartbeat. In many cases, arrhythmias are manageable with medication and changes in the dog’s lifestyle.