Epilepsy consists of exaggerated neuronal activity, excessive or secondary to a defect in the inhibition of neuronal electrical activity, causing neurons to remain connected, sending signals continuously and exaggeratedly, giving rise to epileptic seizures manifesting in the form of involuntary muscle contractions, known as convulsions. Epilepsy can have different causes in the canine species, but in this article we will deal with idiopathic epilepsy, a diagnosis of epilepsy by exclusion and that can affect your dog.
Continue reading this article on our site to find out all the details of idiopathic epilepsy in dogs, its cause, symptoms, diagnosis and treatment.
What is canine idiopathic epilepsy?
Idiopathic or genetic epilepsy, true or essential, is the most common type of epilepsy in dogs. The reason for this is unknown, although appears to have a geneticorigin, to which large breed dogs seem more predisposed. It is usually diagnosed when they are between 1 and 5 years old.
Idiopathic epilepsy is a neurological disease whose main symptom is seizures produced in the cerebral hemispheres due to excessive neuronal electrical activity or a defect in the inhibition of electrical activity, so that the neurons are connected and send signals to each other in an exaggerated way, resulting in epileptic seizures.
Symptoms of idiopathic epilepsy in dogs
The clear symptom of idiopathic epilepsy in dogs is the seizure. The attack can be in two ways:
- A tonic-clonic seizure or focal seizures affecting a single region or muscle group. For example, in this case it is common to notice that the dog's head shakes, although it should be noted that there are other causes that produce this symptom. In partial seizures, dogs typically display rhythmic masticatory or facial muscle contractions in which they lick or chew on a body region or appear to "catch flies."
- In the form of generalized convulsions of the entire body or muscle groups of affected dogs.
These epileptic seizures usually appear at night or while the animal is resting. Generally, the separation between two epileptic seizures is around 4 weeks, and may lengthen over time. During this period some dogs may show disorientation, fear, barking, increased appetite and thirst, blindness or staggering, although it is also common for them to be perfectly fine between seizures.
Causes of idiopathic epilepsy in dogs
There is no known clear cause of idiopathic epilepsy in dogs, hence its name. While epileptic seizures can occur for various reasons, among which we find inflammation, intoxication, infection, congenital malformations of brain tissue, blood vessel problems, tumors or metabolic disorders, in the case of idiopathic epilepsy the origin can be clearly established, although it presents similar characteristics of appearance among dogs that suffer from it.
There are some breeds that are more predisposed, generally those weighing more than 15 kg, highlighting the following:
- Labrador.
- Golden retriever.
- Boxer.
- Belgian Shepherd.
- Australian pastor.
- Bernese Mountain Dog.
- Siberian Husky.
The age is between 6 months and 5 years and its presentation is sudden, acute, whose duration and patterns cannot be predicted. Because of this, it seems to have a genetic or hereditary cause, which comes in the genes of dogs.
Diagnosis of idiopathic epilepsy in dogs
In canine idiopathic epilepsy diagnosis is by exclusion after ruling out reactive and lesional causes that produce epilepsy in dogs. Any good diagnosis must begin with a good anamnesis of the caregiver, where they are asked about their he alth plan, intoxications, diet, changes in behavior or lifestyle, etc.; by a general examination of the dog to assess its physical condition before moving on to specific tests; and for performing a good neurological examination to identify, if any, a damaged neurological location, especially those of intracranial location, as it would indicate a probable symptomatic or reactive epilepsy and rule out idiopathic epilepsy.
It will also be necessary to perform a blood test, biochemistry and urinalysis to find a possible metabolic, electrolyte, liver or disease cause. toxic origin that may be causing seizures in dogs. Neospora or canine distemper virus infections should also be ruled out by laboratory tests such as PCR or serology.
Cerebrospinal fluid analysis may reveal an inflammatory process in the central nervous system. Of all the diagnostic imaging tests, magnetic resonance imaging should be highlighted due to its better resolution and contrast of soft tissues, which can find tumors, infections or congenital anomalies with greater sensitivity.
Treatment of idiopathic epilepsy in dogs
How to cure idiopathic epilepsy in dogs? The treatment of idiopathic epilepsy in dogs should be based on the use of anticonvulsants to minimize or eliminate epileptic seizures and maintain a correct quality of life for the affected dog. It is recommended to start therapy in all those dogs that have presented two or more convulsive attacks in less than 6 months, in which epileptic seizures occur in dogs very close together or their severity is increasing.
The drug used is usually phenobarbital, which is a barbiturate that increases the inhibitory conduction of GABA and Cl-, decreasing the calcium flux to neurons and glutamate-associated neuronal excitation. By presenting hepatic metabolism, it can affect the metabolism of other drugs that use the same pathway. It has good absorption and bioavailability, and can be administered orally or parenterally. It is around 80% effective in controlling seizures in dogs, as long as its levels are kept between 23 and 30 µg/ml. The recommended initial dose is usually 2.5-3 mg/kg/12 hours, but it should be readjusted according to serum levels measured 15 or 20 days after the start of treatment and each dose readjustment.
There are other drugs that can be used to treat canine idiopathic epilepsy, such as potassium bromide, which because it can cross the Cl- ion channels produce a hyperpolarization of neuronal membranes. It is usually less effective than the previous one at the beginning of treatment, but it has a synergistic effect if it is added together with phenobarbital. It does not present hepatic metabolism and the dose is between 30 and 40 mg/kg/24 hours, requiring serum levels of 2000-3000 mg/l in monotherapy and 1000-3000 mg/l if combined with phenobarbital.
How to calm a dog with epilepsy?
It is normal for us to be scared to see our dog suffer an epileptic seizure and we want to calm him down as soon as possible. However, if the medication is not available, it is best not to touch the animal and go to the veterinary center as soon as the attack is over. We should only move the dog if the attack occurs in a place where it can be damaged. If the environment is safe, it is preferable to leave it so as not to cause the attack to repeat itself.
