Dog Seizures: Causes, Signs, Treatments & Care (Vet Answer)

If you’ve ever seen your dog have a seizure, you know how horrible it can be. Most of the time, a seizure lasts less than a minute, but it can feel much longer, and it’s totally normal to feel helpless and scared. Seizures can occur for many different reasons. It might be a one-off event, a reaction to something they’ve eaten, a sign of illness, or the start of a seizure disorder. You’re going to want to know what caused your dog to have a seizure in the first place and what to do about it, so the first thing you’ll need to do is get in touch with your vet. The next step is to learn a bit more about seizures, which is what has brought you here. We’re going to take a look at everything you need to know about seizures in dogs, including what conditions can cause them, how they are treated, and what signs you should be on the lookout for.

What Is a Seizure?

A seizure, or fit, happens when there is uncontrolled electrical energy between the brain cells (AKA neurons). Depending on the underlying cause, a seizure could last seconds, minutes, or even longer. They can be an isolated episode, happen in groups, or become a regular occurrence. Seizures are categorized based on how they present, which you’ll see in the following: Generalized or Grand Mal Seizures: The most common type of seizure affecting dogs. It affects all or most of the body and usually includes:

• Muscle trembling or twitching
• Vocalizing (barking, yelping, crying)
• Collapse with loss of consciousness or responsiveness
• Loss of control over bladder/bowels
• Paddling of the limbs
• Frothing at the mouth, champing of the jaw

Focal Seizure: Also known as partial or localized seizures, they affect a single limb or part of the body with twitching or trembling. These are uncommon in dogs and usually indicate a focal lesion or mass in the brain.

Absence Seizures: Also known as “petit mal,” these seizures present as “spaced out” behavior, gazing at nothing, and unable to respond to stimulus until the seizure has ended. These can be difficult to recognize, as the dog may show no other clinical signs, so they are sometimes mistaken for dementia or hearing/vision loss.

Seizures can also be characterized based on the time period over which they occur, including:

Single/Isolated Seizure: May progress to other forms or may just be a one-off episode. A true isolated seizure is more likely to be triggered by an external influence, such as a toxin or high temperature, or a transient chemical imbalance, such as low blood sugar (hypoglycemia) or low calcium (hypocalcemia).

Cluster Seizures: Refers to two or more seizures within a 24-hour period.

Seizure Disorder/Repeated Seizures: For example, epilepsy, where more than two seizures over a longer period of time.

Status Epilepticus: Seizures that last more than 5 minutes, or repeated seizures without a gap or period of consciousness between them.

Refractory Seizures: When seizures keep occurring despite the use of anti-seizure medication. Seizures may be refractory from the start or progress over time as the condition becomes resistant to medication.

What Are the Causes of Seizures in Dogs?

Seizures can occur for many reasons, and sometimes, especially in the case of a single, isolated seizure, we never find out the cause. Below are 10 potential causes of seizures in dogs, starting with the most common.

1. Epilepsy

There is no specific test for epilepsy, and it is only diagnosed when all other causes of seizures have been ruled out. For this reason, it is also called idiopathic epilepsy because the actual cause is unknown. However, scientists believe that there is an inherited disorder that causes a chemical or functional imbalance that leads to seizures in affected dogs.

All breeds can get epilepsy, but some are more commonly affected than others, including Border Collies, Labradors, and Golden Retrievers. Seizures usually start to occur when dogs are between 6 months and 6 years old and will generally affect them for life.

In most cases, epilepsy can be successfully managed with medication, but over time, we often need to increase their dosage or add additional medications. The drugs used to treat seizures are also sedatives, so the aim of managing epilepsy is to stop or minimize the frequency and severity of seizures without causing excessive sedation, so it’s not unusual for a dog on epilepsy medication to still have an occasional seizure.

Once treatment has started, it is dangerous to withdraw it, as this can trigger severe and frequent seizures. Apart from causing sedation, anti-seizure medications can have other side effects, particularly on the liver, and patients are only started on treatment if their seizures are quite frequent, severe, or long lasting, and dogs on medication should have regular blood tests to monitor their liver function.

2. Low Blood Sugar

Hypoglycemia can trigger a seizure and may be seen in very young or malnourished dogs. One cause of hypoglycemic seizures in dogs is a tumor on the pancreas called an insulinoma, but it can also occur as a result of liver failure, certain toxins (e.g., xylitol), or insulin overdose.

3. Brain Tumors

Although brain tumors are often benign, the very limited amount of space inside the skull leaves little room for expansion. This means that a mass growing in the brain will eventually start to put pressure on the surrounding tissues, causing different signs, depending on what part of the brain is affected, and seizures are quite common.

4. Toxins

Any substance that negatively affects the electrical or chemical processes in the brain can cause seizures. Some toxins may affect the brain directly or cause disruption indirectly by affecting other organ systems. The types of toxins that may result in seizures include:

• Poisons, such as antifreeze, rat bait, or pesticides
• Biological substances, like venom/toxins found in plants or animals
• Food additives/ingredients, such as xylitol, chocolate, or salt
• Heavy metals, such as lead and zinc
• Illicit drugs, such as cocaine, methamphetamines, and cannabis
• Medications

Seek veterinary advice if you’re concerned about your pet’s well-being.

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5. Metabolic Disorders

This refers to diseases that affect how the body metabolizes food and other substances. If the liver or kidneys are unable to filter out waste products or harmful substances correctly, they can have a toxic effect on the brain, leading to seizures. Examples include portosystemic shunt, periparturient hypocalcemia of dogs with new puppies, and renal failure.

6. Heart Disease

If the heart is not functioning properly, it can result in reduced blood flow or cause clots to form in the blood vessels supplying the brain. This can starve the brain of oxygen (hypoxia), resulting in seizure activity.

7. Inflammatory Disease

• Granulomatous Meningoencephalitis (GME): Seen most commonly in smaller breeds, such as Chihuahuas, Miniature Poodles, or small Terriers, GME is the inflammation of particular brain cells.
• Meningitis: Inflammation or infection of the cerebrospinal fluid (CSF). The most common form in dogs is idiopathic or steroid-responsive meningitis, while bacterial and viral meningitis are rare.

8. Infection

• Protozoal: Neospora and Toxoplasma are protozoal organisms that can cause neurological signs, including seizures. Most infections are mild and quickly fought off by a healthy immune system, but immunocompromised or very young animals can develop a more serious illness and require treatment.
• Bacteria or Viruses: Some infections, such as Canine Distemper, can produce neurological signs, such as seizures, directly. Other times, seizures occur as a result of a high fever caused by the immune response to infection.
• Fungal: Cryptococcus, a fungal infection spread in bird feces, is usually asymptomatic in dogs but can cause seizures in immunocompromised individuals.

If you notice any of these signs, make a note of the time, and make sure your dog is in a quiet, dark room with blankets and pillows around them.

How Can I Tell If My Dog Has Had a Seizure?

If your dog has epilepsy, you might be worried about them having a seizure when you’re asleep or out of the house. This can happen, and you may never know about it. However, some dogs can have quite a long post-ictal phase, and you might come to recognize some signs that suggest they have had a seizure. For example, your dog might seem sleepy, wobbly, or particularly clingy. There might also be evidence, such as objects knocked over or disturbed, as well as urine, feces, or vomit in the house. If you are worried about leaving your epileptic dog, here are a few tips to maximize their safety (and your peace of mind):

• Invest in a pet camera.
• Confine your dog to one room in the home that has no sharp objects or anything they can knock over. Avoid crates, as they can get limbs or jaws stuck between the bars.
• Create a “seizure nest” for them with soft bedding and pillows.
• Turn off any bright lights.
• Consider playing a sleep sound or white noise device to reduce noise disturbance.
• Make sure you always have a ready supply of their medication.

Conclusion

Seizures are frightening for dogs and their humans and can be the result of anything that may disrupt normal brain function by damaging neurological tissue, damaging other organ systems which then affect the brain, or causing a dangerous elevation of body temperature. However, epilepsy is the most common cause of seizures in dogs. Fortunately, this is a condition that can usually be well managed with medication. Although seizures can occur as isolated events and further investigation and treatment may not always be necessary, you should always contact your vet immediately if your dog has had—or is having—a seizure. Always be careful around your dog when they are having or have just had a seizure, as their altered mental state can cause them to act completely out of character. We hope this has helped you understand more about seizures in dogs, but remember to get in touch with your vet if you have any other questions or concerns. See Also: 

• Can Dewormers Cause Seizures? Health & Safety Facts (Vet Answer)

• What If My Dog Has a Seizure When I’m Not Home? Our Vet Explains What to Do

Featured Image Credit: Przemek Iciak, Shutterstock