Epilepsy can affect some dogs and is characterized by repeated and often impressive seizures.
Just like in humans, epilepsy is a disease that is common in dogs. It has various origins and the affected animal cannot be cured. However, there are treatments that can reduce the intensity and frequency of the seizures, so that the dog can live a more or less normal life.
Canine epilepsy
A dog is said to be epileptic when he is subject to several convulsive seizures due to an overexcitation of certain neurons. These seizures are characterized by sometimes spectacular convulsions and the owner of the sick dog may feel helpless.
The intensity and frequency of epileptic seizures in dogs varies from one individual to another.
Epileptic seizures in dogs
Seizures in dogs may occur for no apparent reason or may be triggered by stressful events such as a sudden, unusual noise or light stimulation.
Before a seizure occurs, it may be heralded by certain signs that constitute the phase called prodrome. This phase varies in duration (it can last up to several days) and may be characterized by behavioral changes or unexplained fatigue. These symptoms are sometimes difficult to detect or even non-existent. However, owners who are used to epileptic seizures will be able to recognize the signs specific to their pet.
When a seizure is imminent, the dog may show these same signs, but in a more obvious way. This phase is called the aura. It can be compared to a partial seizure.
It precedes the actual seizure, the ictus, which is made up of convulsions and possibly excessive salivation. This phase can last more than 5 minutes. If the seizure is generalized (i.e. the overexcitation of the neurons concerns both cerebral hemispheres), the seizure may be composed of pedaling movements, called the clonic phase, as well as a tonic phase during which the animal will be in opisthotonos (stiffness of the limbs and the neck)
Finally, the post-ictal phase, during which the dog recovers from the seizure, is manifested by a sort of despondency. The animal looks a little lost and may have difficulty walking or even standing for a while. It may also have difficulty breathing because of saliva blocking the airways. This phase may last several days. The animal may also show aggression and bite.
Structural, reactionary and essential epilepsy
These are the 3 types of epilepsy found in dogs
Essential epilepsy
This is the most common form and can be treated medically. It is also called primary or idiopathic epilepsy. Its origins are poorly understood, as it is associated with several constitutive diseases of the neurons that cause them to depolarize all at the same time. These diseases are often of hereditary origin and due to mutations in several genes. Seizures can be triggered by external stimuli such as noise, excitement, sight or smell.
The first seizures of essential epilepsy in dogs can occur at the age of 6 months. In some individuals, they occur much later, around 6 years of age.
Some breeds are more prone to seizures than others: Beagles, German Shepherds, Belgian Shepherds, Border Collies, Boxers, Cockers, Colleys, Irish Setters, Labrador Retrievers, Poodles, St. Bernards, Siberian Huskies, Welsh Corgis and Fox Terriers.
Secondary epilepsy
Also called structural or intracranial epilepsy, it is the result of an abnormality in the structure of the brain, itself consecutive to a stroke, a congenital malformation, a tumor, a parasitic or viral encephalitis.
Structural epileptic seizures occur at any age in dogs. It is often associated with other symptoms, such as difficulty moving or coordinating movements.
Reactive epilepsy of extra-cranial origin
The origin of reactive epilepsy in dogs is a blood disorder that affects brain function.
This form of canine epilepsy can be caused by hypoglycemia following a tumor of the pancreas, diabetes or heavy exertion, for example. Certain medications can also cause it, such as those containing ibuprofen. Toxic substances are also likely to cause it, such as Temik used as an anti-slug product (the marketing of which is prohibited in France and in Europe) or certain insecticides such as organochlorines. This form of epilepsy can also be caused by hepatic insufficiency at the origin of hepatic encephalopathy.
Veterinary management of epilepsy in dogs
An epileptic seizure is an emergency, the seizure must be stopped, especially if it lasts more than 5 minutes, to avoid irreversible neuronal damage. The veterinarian will evaluate several parameters such as heart function, temperature and certain blood parameters.
The owner can also try to mitigate the animal’s seizure: in case of a seizure, it is advisable to create an environment as stress-free as possible, without light or noise.
Generally speaking, there is only a treatment for the first form of epilepsy, the so-called essential form. Even then, medical treatment does not cure the disease, but rather improves the dog’s quality of life by reducing the frequency and intensity of seizures.
If the seizures are of extra-cranial origin, the cause will have to be treated (diabetes, liver failure…).
After the diagnosis, the veterinarian usually prescribes a sedative drug, such as gabapentin or phenobarbital for example.
An animal that presents only one isolated epileptic seizure will not be prescribed any particular treatment. Indeed, the treatment aims at reducing the frequency and the violence of the seizures, if they occur often. It is therefore important to note the dates of appearance of the seizures and their duration so that the veterinarian can adapt the treatment if necessary.
However, treatments against canine epilepsy are not without undesirable effects: drowsiness, lack of muscle tone, etc.