Seizures and Brain Diseases in Your Dog

Types of Seizures and Why They Happen

Small Worried Looking Mixed Breed Dog
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A seizure is the result of sudden and abnormal neurological activity, basically a kind of electrical storm in the brain. In humans and dogs, seizures can manifest themselves in many ways and have a multitude of causes. However, seizures are always accompanied by altered or loss of consciousness. They may last a few seconds, several minutes, or, in the worst cases, hours.

Are Seizures Dangerous to Dogs?

Most seizures are not considered life-threatening.

However, they do indicate a problem in the brain. If you suspect that your dog has had a seizure, contact your vet as soon as possible. Be aware that a seizure lasting more than five minutes is considered an emergency situation. It is imperative that your dog is seen by a vet immediately to prevent brain damage and hyperthermia (elevated body temperature). In addition, the occurrence of more than three seizures in a 24 hour period is also an urgent matter that requires a trip to the vet right away.

Causes of Seizures in Dogs

Seizures occur for a number of reasons. If your dog has a seizure for the first time, even if it was mild, it's important that you visit your veterinarian soon. In an attempt to find a cause, your vet will recommend a variety of diagnostic tests. This typically starts with blood tests but may lead to advanced brain testing such as CT, MRI, and cerebrospinal fluid (CSF) tap.

In the case of the latter, your vet might refer you to a veterinary neurologist. The following disorders may be the source of seizures in a dog:

  • Structural or developmental abnormality
  • Reaction to toxin or allergen
  • Systemic disorder, such as liver shunt or thyroid disease
  • Bacterial or viral infection
  • Brain tumor (malignant or benign)
  • Idiopathic Epilepsy

Seizure Treatments for Dogs

Fortunately, seizures in dogs can often be regulated with medications and/or dietary changes. Treatment options may vary depending on the suspected cause of the seizures and the type of seizures your dog has been having. It is important that you adhere to your veterinarian's recommendations if you want treatment to be successful.

Types of Seizures in Dogs

Seizures in dogs are categorized as generalized (full body, convulsive) or focal (mild and isolated to a specific area of the body. Often, seizures are preceded by a period of anxiety, restlessness and/or apprehension that is called the "pre-ictal phase". The seizure itself is called "ictus." Following the seizure is the "post-ictal phase", which may involve several minutes to hours of disorientation, stupor and/or blindness.

Generalized Seizures in Dogs

These seizures are sometimes referred to as "grand mal," though this term is used less commonly in veterinary medicine than in human medicine.

Generalized seizures visibly affect the entire body and are characterized by overall stiffness and/or spastic, involuntary movements. During this type of seizure, the dog typically experiences full-body rigidity along with convulsions. The dog may lose control of its bladder and/or bowels. Some dogs will vocalize. Also called "tonic/clonic" seizures, generalized seizures are the most common type of seizures seen in dogs.

Focal Seizures in Dogs

Sometimes called partial seizures, these are isolated to a particular part of the brain and therefore affect a specific part of the body. Focal seizures are typically quite mild and may simply be characterized by facial twitching. However, they can occur in another part of the body, such as a limb. Sometimes, a focal seizure will look like a fainting spell or a brief period of disorientation. In other cases, a dog experiencing this type of seizure may compulsively snap at the air (sometimes called "fly biting").

Cluster Seizures in Dogs

If your dog has more than one seizure in a 24 hour period, then they are considered cluster seizures. Dogs that experience these types of seizures have a more urgent need for medical treatment than dogs with occasional seizures. Additionally, if your dog has more than three seizures in a 24 hour period, it is considered an emergency. Your dog should be seen by your primary care veterinarian or an emergency veterinarian that day. Delaying may result in increasing frequency and severity of the seizures, posing a greater threat to your dog's health.

Canine Status Epilepticus

Status epilepticus is a prolonged seizure or a series of seizures that occur continuously. This is a dire emergency situation that, if untreated, can lead to brain damage, hyperthermia (elevated body temperature) and even death. Dogs in status epilepticus require hospitalization and often need to be placed on a drip of Valium (diazepam) or another drug to stop the seizures.

Phases of a Dog Seizure

Many seizures are preceded by a period of abnormal behavior called the pre-ictal phase. During this stage, dogs often exhibit signs of anxiety and apprehension. They may whine, pace, and/or pant. Not all dogs display pre-ictal signs, and some may only do so intermittently.

The seizure itself is sometimes referred to as ictus or the ictal phase.

Following nearly every seizure is the post-ictal phase. This period may last minutes to hours and is often characterized by stupor, disorientation and/or blindness. The post-ictal phase can vary with each seizure. This phase should not be confused with the seizure itself.

Canine Idiopathic Epilepsy

Epilepsy is an idiopathic disease, meaning its cause is unknown. There is no specific test to diagnose epilepsy, so advanced diagnostic tests (CT, MRI, spinal tap) are recommended in order to rule out other causes for the seizures. However, a presumptive diavgnosis is sometimes made when a dog fits the criteria for epilepsy. Typical onset of epilepsy is between the ages of one to five years. Breed and family history may also play a role. Though uncommon, dogs outside of this age range may still be epileptic. Many epileptic dogs will respond quite well to drug therapy, but they usually must be on medications for life.

If you suspect that your dog is having a seizure, do not panic. However, there are some steps to take. Learn what to do if your dog has a seizure.