A seizure results from sudden and abnormal neurological activity—basically, it's a type of electrical storm in the brain. In both humans and dogs, seizures can stem from a multitude of causes and are usually accompanied by alteration or loss of consciousness. They may last a few seconds, several minutes, or, in the worst-case scenarios, hours. Depending upon the issue, treatment can be as simple as a regular dose of medication. However, seizures connected with brain disease can result in brain damage, or even death, if they go untreated. Understanding the causes and types of seizures in dogs can make the experience less stressful.
What Are Seizures?
Seizures in dogs are categorized as generalized (full-body, convulsive), focal (mild and isolated to a specific area of the body), or cluster (happening in succession). Often, seizures are preceded by a period of anxiety, restlessness, or apprehension 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, or blindness.
Generalized seizures (also called tonic or clonic seizures) affect the entire body and are characterized by loss of consciousness, overall stiffness or by spastic, involuntary movements. The dog may lose control of its bladder and bowels and some dogs may even vocalize during the event. Focal seizures, sometimes called partial seizures, 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 be characterized by facial or limb twitching. Sometimes a focal seizure will look like a brief period of disorientation, or the dog may compulsively snap at the air (sometimes called "fly biting"). Cluster seizures refer to a series of three or more seizures that happen within a 24-hour period or two or more seizures that happen without a full return of consciousness between them. Dogs that experience cluster seizures need medical treatment right away and should be seen that day by a veterinarian.
Symptoms of Seizures in Dogs
Most seizures are not considered life-threatening, however, they do indicate a problem in the dog's brain. If you notice your dog acting unsteady or nervous, then collapsing, jerking, and foaming at the mouth, it may be having a seizure. Seizures can sometimes be the result of poisoning or environmental factors, so having one brief seizure may not be a serious event. Yet, several seizures in a row or a seizure that lasts longer than five minutes is considered an emergency situation that can be life-threatening. Call your vet immediately. 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. And even if the seizure was brief and not recurring, it's still best to schedule a vet appointment, even if he's acting normal.
Causes of Seizures
Seizures occur for a number of reasons. Your dog may be having a reaction to a toxin. It could be suffering from a bacterial or viral infection, which can often be treated by antibiotics or antiviral drugs. Low blood sugar can cause seizures and is commonly seen in small breed puppies. In more severe cases, your dog could be suffering from a brain disease, like idiopathic epilepsy, or metabolic issues such as a liver or thyroid disorder. Lastly, structural abnormalities or tumors (both malignant and benign) can also contribute to seizures in dogs.
If your dog is having a seizure, the first thing to do is call your vet, who will run diagnostic tests, starting with blood tests and a physical examination and possibly X-rays, in an effort to diagnose the cause. If initial testing is inconclusive, a veterinary neurologist may run a CT scan, an MRI, or perform a cerebrospinal fluid (CSF) tap to gather further information on your dog's condition. Fortunately, most seizures in dogs can be regulated with medication, though some breakthrough seizures may be possible. But depending on the cause, simply avoiding a toxic substance, treating underlying conditions in the brain or the liver, or using alternative therapies like acupuncture may help. Sometimes, like in the case of a tumor, your dog will need surgery before its seizure episodes resolve. It is important that you adhere to your veterinarian's recommendations for a successful outcome.
A prolonged seizure or a series of seizures that occur continuously are called status epilepticus. This is a dire situation that, if left untreated, can lead to brain damage, hyperthermia (elevated body temperature), and even death. Dogs in status epilepticus require hospitalization and often need a constant infusion of medication to stop the seizures.
What Is Brain Disease in Dogs?
Canine epilepsy is an idiopathic disease with no known cause. The typical onset ranges between the ages of 1 to 5 years and breed and family history can play a role in its development. There is no specific test to diagnose epilepsy, so advanced diagnostic testing (like a CT scan, MRI, and spinal tap) is often recommended in order to rule out other causes. However, sometimes a presumptive diagnosis is made when a dog fits the criteria for the disease. Many epileptic dogs respond quite well to drug therapy, needing it throughout their lives to maintain a happy lifestyle.
How to Prevent Seizures
With a myriad of causes, there are only a few ways to prevent seizures in dogs. One preventative measure is to keep your dog away from toxic substances and poisons like paint solvents and antifreeze. Stress can cause a dog who is prone to seizures to have an episode, so if your pet has had seizures in the past, minimizing stress in its environment is very important.