Seizures in Dogs: Types, Symptoms, Causes & Preventions

Seizures in dogs are one of the scariest medical emergencies a pet owner may witness. Owners can feel helpless watching their pets experience these violent behaviors without knowing how to intervene. 

Pets are often unaware of what is happening and can injure themselves, release bodily fluids, and may remain dazed for some time after the event. 

Knowing how upsetting this can be for owners, the goal of this article is to bring some clarity to owners who have dogs with seizures. 

We will educate pet owners on how to recognize a seizure and how/when to intervene. We will also discuss how to identify the underlying causes of seizures and what can be done to prevent seizures from occurring. 

What Are Seizures in Dogs?

Seizures are a prevalent medical emergency in our canine friends and are the most common neurological disorder seen in dogs. Another term for seizures is epilepsy.

This broad term refers to an abnormality of the brain that causes uncontrolled electrical activity between brain cells. This abnormal electrical activity causes changes in muscle tone, movements, behaviors, or states of awareness. 

Symptoms of Seizures in Dogs

Seizures can present as focal or generalized. Focal seizures typically only involve a single side or part of the body. 

These can manifest as facial twitching, chewing movements, limb paddling, drooling, abnormal eye movements, or strange behaviors. Dogs with focal seizures often maintain consciousness. 

We contrast this to generalized seizures where animals often lose consciousness and will have bilateral involuntary movements of their limbs. Paddling and intense tremoring are typical of a generalized seizure. 

Animals may drool, vocalize, urinate, or defecate during a generalized seizure. Luckily, seizures are not painful, but they are certainly scary to watch. 

The duration of seizure activity is unpredictable, but it is important to note that any seizure lasting longer than five minutes is a true emergency. 

Any animal having more than two seizures in less than 24 hours requires veterinary intervention immediately. 

Prolonged seizure activity can make the initial treatment of seizures more challenging and can predispose animals to hyperthermia, recurrence of seizure activity, and fluid build-up in the lungs.

While it may not be intuitive to most pet owners, it is important to take some mental notes or record a video while a seizure is occurring. 

The purpose of this is to gather information for your veterinarian that will be helpful to guide the treatment of the seizure. It may also be helpful to understand why the seizure is occurring. 

Try to keep note of:

• When the seizure happened
• If there was any precipitating behavior or event
• How long the seizure lasted
• Your dog’s behavior before and after the seizure

Many animals may return to normal after a seizure episode, but some may experience a “postictal” period. The postictal period is where they will behave abnormally for varying amounts of time after the seizure. 

Many animals will often demonstrate a “preictal” phase as well. This phase is associated with abnormal behaviors just before the seizure occurs. Some dogs may appear anxious, hide, shake, drool, or whine. 

Once an owner becomes familiar with their dog having seizures, these behaviors are often the first clue. 

What Causes Seizures in Dogs?

Now that we know how to recognize a seizure, let’s discuss why seizures occur in the first place. There are several categories of epilepsy to help us group the types of seizures in dogs. These include idiopathic, structural, and reactive seizures.

Idiopathic seizures are presumed to be genetic and generally occur in young dogs between 1-5 years of age. Predisposed breeds include Collies, Australian Shepherds, German Shepherds, Golden Retrievers, Labrador Retrievers, Siberian Huskies, and several more. 

Idiopathic epilepsy is a diagnosis of exclusion after other causes of seizures are ruled out. In older dogs with an unknown cause of seizures, these are termed cryptogenic epilepsy. 

Structural seizures occur secondary to disease within the brain itself. Some examples are infectious, inflammatory, and cancerous diseases of the brain. 

Congenital malformations of the brain may also be seen as a cause in younger animals. The most common cause of structural seizures in older dogs is cancer, such as meningioma.

Reactive seizures are those that occur in response to a systemic abnormality such as an electrolyte issue, low blood sugar, organ dysfunction, or toxicity. 

Diagnosing Seizures in Dogs

Differentiating between types of seizures is often accomplished through thorough history taking and performing various diagnostics such as bloodwork and advanced imaging. 

Bloodwork is performed to look for changes in blood sugar, electrolytes, and markers of organ function. Bile acid testing or ammonia levels may be checked to rule out liver disease or portosystemic shunts as a cause of seizures. 

Radiographs may be taken to assess for evidence of cancer, especially in older animals. Advanced imaging generally implies MRI or CT scans to identify lesions within the brain itself. 

Testing of the cerebral spinal fluid is often performed concurrently to screen for evidence of infection, inflammation, or cancerous processes affecting the brain. 

Advanced diagnostics such as MRI and CSF sampling are typically performed under the guidance of a veterinary neurologist.

After we have discovered that a dog is having seizures, we need to determine how to treat and prevent them. 

First and foremost, we must screen and treat any systemic cause of seizures. This may include correcting low blood sugar or treating known toxicities. 

Often, by treating the underlying cause, the seizures may resolve without further intervention. If there is suspicion of structural disease, this will also require appropriate treatment as deemed necessary by your veterinarian.

Treatments of Seizures in Dogs

Once we have ruled out systemic and structural causes as a source of seizures, then the next step is to determine the seizure frequency and suspected cause. 

For healthy dogs who have only had one, self-limiting seizure, treatment is not necessarily indicated. 

We do not recommend treatment because some dogs may only ever have one seizure and never any recurrence, or can be seizure-free for a long time. 

The cost and risk of antiepileptic (AED) medications do not outweigh the benefit in those cases. 

Treatment with antiepileptic medication is indicated in dogs who:

• Have more than one generalized seizure in less than 24 hours
• Have two or more seizures in less than six months 
• Have severe signs during their postictal period — biting, blindness, etc

Antiepileptic drugs work by inhibiting or altering neurotransmitters in the brain or changing ion channels to prevent seizure occurrence. 

The AED of choice varies amongst clinicians. Many factors must be included in the decision-making to start an AED medication. Not only must a drug be effective, but it also has to be well-tolerated and affordable to the owner. 

While these medications can be life-saving, many of them carry significant side effects and also the need for long-term monitoring. 

Some of the most common AED medications include phenobarbital, levetiracetam, potassium bromide, or zonisamide. 

Your veterinarian will have a thorough discussion with you about the various options and which is best for you and your pet. 

Many dogs will respond well to AED therapy. Some breeds can experience refractory epilepsy, which may require the use of combination therapy. Unfortunately, some dogs will not respond well to AED therapy despite aggressive treatment. 

It is also important to discuss therapeutic options with your veterinarian for breakthrough seizures. This is medication you can give during a seizure episode to stop the seizure or prevent subsequent seizures from occurring. 

The most common at-home treatments include diazepam, midazolam, or clorazepate. You can keep these medications on hand to quickly and safely treat a seizure at home. 

Preventing Seizures in Dogs

Is there any way to prevent seizures from happening? Unfortunately, for many causes of seizures, there is no source of prevention. 

Systemic causes of seizures can be avoided by ensuring that common household toxins are out of reach. 

Small breed puppies prone to low blood sugar should be fed regularly. Dogs with idiopathic epilepsy should be administered their medications on a strict regimen. 

Any potential triggers of seizures should be avoided such as stressful events, loud noises, or flashing lights.

What to Do If Your Dog Has a Seizure?

Do’s

• Make sure they are in a safe place. If able, move them away from any objects that may fall on them, stairs, or glass. 
• Record the event if able to share it with your veterinarian.
• Contact your veterinarian or an emergency facility if this is your dog’s first seizure.
• Keep a diary of seizure activity.
• Consider an appointment with a veterinary neurologist if seizures are worsening or hard to manage.

Don’ts

• Place your hands near their face or mouth. Dogs will often bite down during a seizure. You can be seriously injured as your dog will have no control over its behaviors.
• Allow a dog to continue to seizure for more than 5 minutes without seeking medication attention.
• Allow any children or other animals near a seizing dog.
• Administer any oral medications, food, or water during a seizure. 
• Skip/miss doses of antiepileptic medications.

Having a dog with seizures can be stressful, but with proper education and a strong relationship with your veterinarian, your dog can have a great quality of life. 

Hopefully, this article has eased some of your worries and answered questions you may have about seizures in dogs.