Seizing the Day: Understanding Seizures in Our Pets
Dogs and cats have complex nervous systems, and this is part of why humans love them. Their brains are what lets them live, learn, and love. But having an advanced central nervous system also creates opportunities for things to go wrong. Seizures are one example of this. A seizure is excessive and inappropriate electrical activity in the brain, and can appear in a variety of ways.
When most people picture a seizure, they are thinking of a generalized seizure, which is also called a grand mal seizure in humans. This involves loss of consciousness, uncontrolled limb movements, and sometimes urination, defecation, salivation, or vomiting. It usually lasts seconds or minutes, but can last longer in certain cases.
Seizures can also be partial (or focal). Pets with partial seizures may still be aware, but have twitching of part of the body or face, or abnormal limb movements. In either case, the seizure is often preceded by a prodrome, or pre-ictal phase.
This varies pet to pet, and can last from hours to days.
Typically, the prodrome involves behavioral changes, such as unusual attention seeking, excitement, or hiding. Owners may not recognize a pet’s prodrome, or it may become familiar if seizures are frequent.
After a seizure, most pets experience a post-ictal phase of minutes to hours. During this time, pets are typically disoriented and wobbly. They may even be temporarily blind, or just not acting quite themselves.
If you think your pet is experiencing seizures, the first step is to consult with your veterinarian. Once at the vet, expect that a staff member will take a detailed history.
Finding out what happened immediately before, what exactly the episode looked like,and what happened afterwards can be very critical in differentiating a true seizure from fainting, a musculoskeletal disease, or even a balance issues.
The vet will also conduct a thorough exam, including a neurologic assessment. Depending on the underlying cause of the seizures, your dog or cat may appear completely normal between seizures, or could have notable deficits.
Generally, screening labwork, including a complete blood count, serum chemistry, and urinalysis will be recommended. These tests help look for diseases outside the brain which could be causing seizures.
Your vet may also suggest thoracic radiographs (chest x-rays) if your pet is older, which can be used to screen for spread of cancer to the lungs. He or she may discuss referral to a neurologist, a veterinarian who has pursued additional training in the nervous system. Neurologists typically work at referral hospitals, and have access to magnetic resonance imaging (MRI) or computed tomography (CT). These types of advanced imaging are the only way to know for sure if there is a lesion in the brain causing the seizures. Other tests could include a cerebrospinal fluid tap, screening for certain infectious diseases, or toxin testing.
The reason suggested tests can vary is that there are many possible causes of seizures. Depending on your pet’s age and breed, some of these causes will be higher on the list of possibilities. Some types of seizures are caused by issues outside the brain, including toxins, metabolic abnormalities, low blood sugar, or electrolyte imbalances. Others are caused by intra-cranial issues, including tumors, congenital malformations, injury, or loss of blood supply. Many dogs with seizures have a condition known as idiopathic epilepsy.
This means that there is no known cause, and even an MRI does not reveal a problem with the brain. There may be a hereditary component to some cases of idiopathic epilepsy. Idiopathic epilepsy tends to develop between the ages of one and four in dogs. For younger pets, toxins or congenital issues may be more likely. Pets that develop seizures later in life are more likely to have a structural issue such as a brain tumor.
The type of treatment will depend on the underlying cause of the seizures. If seizures are secondary to an extra-cranial problem, then they will likely resolve once that issue is corrected. For pets with intra-cranial disease or idiopathic epilepsy, medical therapy may be indicated. However, not every pet that has had a seizure requires medication. Typically, medication is recommended if the pet if having a seizure more often than once every two months, or if seizures are prolonged or interfering with their quality of life.
Before starting therapy, it is important to understand the goals of treating seizures. The main objective is to decrease seizure frequency to an acceptable level with minimal side effects. Most pets with epilepsy will have breakthrough seizures at some point, but the seizures should occur less frequently.
There are many different medications used to treat seizures, and each has benefits and drawbacks. Almost all have some type of side effect, which could include sedation, wobbliness, increased thirst and appetite, or increased risk for other conditions (such as liver damage or pancreatitis). Some types of side effects may be most notable early on in administration, and decrease with time. Finding the right medication will involve a discussion with your vet about goals and priorities. There are many different anticonvulsants, and he or she can help you pick the best one for you and your pet.
Factors may include cost, how frequently you can give a medication, tolerance for certain side effects, and ability to conduct routine labwork while your pet is on the medication. Regardless of the type of medication, it is essential to be prepared to give the medication for a long time — potentially the rest of your pet’s life. Anticonvulsant medications should never be stopped or altered without consulting a veterinarian, as this could lead to dangerous complications. Additionally, treatment may have varying degrees of success depending on the cause of seizures. For example, a young dog with idiopathic epilepsy may achieve excellent seizure control and live a very normal life. An older dog with a brain tumor may gain increased quality of life with anticonvulsant drugs, but seizures may become refractory to treatment eventually.
In certain cases, emergency treatment of seizures may be indicated. This could involve administering injectable drugs to stop an ongoing seizure. It could also include hospitalization for continuing injectable drugs, or even a continuous drip of medication. This can be necessary to break the cycle of an over-excitable brain. Once prolonged seizure activity has occurred, there is an increased risk for further seizures.
Obviously, these types of treatments are not feasible at home.
So what should you do if you are with your pet when they seize? First of all, don’t panic! A seizure is scary to watch, but is not immediately life threatening in most cases. If the pet is on an elevated surface, such as a couch or a bed, you may move them to a level surface where they cannot fall. If the seizure only lasts a few minutes, you may not have to do anything. If your pet has previously had seizures, your vet may have sent home medication to be given in the rectum or the nose to stop an ongoing seizure. Remember to not go near your pet’s mouth during a seizure — he or she is not aware of what is happening, and could bite you unintentionally. If the seizure resolves quickly, you should make sure to write the details down.
Keeping a seizure journal is important if you have a pet with epilepsy. Recording the date, duration, and other details of the event can help to determine if medication is helping. So how do you know if you should urgently seek veterinary care for a pet that has had a seizure? If your pet has never had a seizure before, they should be seen quickly.
Otherwise, events that require emergency treatment include seizures lasting longer than five minutes, more than three seizures in a twenty four hour period, or a seizure that starts almost as soon as another one stops. These can cause life threatening elevations in body temperature or potentially brain damage.
If you are ever unsure if your pet should be seen, don’t hesitate to call us! Our answering service will get to the phone at any time of the day or night, and one of our veterinarians can meet you at the clinic if your pet needs to be seen.