A: Seizures are always abnormal and warrant a visit to your veterinarian. Brief seizures in and of themselves are not particularly dangerous. However, they are frequently a symptom of serious problems. In pets seizures are caused by five basic categories of disease.
First, exposure to certain toxins may lead to seizures. Usually, this is one of the easier causes to rule out. Certain medications, lawn and garden products, household cleaners, and pesticides can lead to seizures. Mold toxins in mulch, garbage, or wildlife carcasses may also induce seizures or tremors. Prompt treatment is essential for any suspected toxin exposure.
Second, seizures can be caused by underlying metabolic diseases. Liver diseases, kidney failure, hormone imbalances, and certain tumors may produce secondary seizures. Occasionally metabolic defects may occur due to a birth defect or nutritional imbalance. Your veterinarian will want to run a series of blood tests to rule out metabolic causes of seizures. The prognosis for these diseases varies significantly. Some are completely correctable and some are universally fatal.
Third, some seizure-like activity is caused by heart or vascular disorders. Irregular heart rhythm, extremes in blood pressure, and blood clots can produce collapse and tremors. Listening to your pet’s heart will give your veterinarian a lot of information. Sometimes an electrocardiogram (EKG) or an echocardiogram (sonogram) may be indicated. Very occasionally, your veterinarian may have your pet wear a monitoring harness for a period of time to detect abnormal heat activity during the events. Most heart diseases that cause seizure-like activity can be treated successfully for varying periods of time.
Fourth, diseases of the brain and nervous system frequently lead to seizures. Brain tumors, birth defects, meningitis, encephalitis, head trauma, and strokes all fall into this category. If a dog or cat begins having seizures over the age of five, and the above three categories have been excluded, then brain disease becomes the most likely cause. These diseases are difficult to diagnose. The best way to see inside the brain is through magnetic resonance imaging (MRI). Sometimes sampling of fluid from around the spinal cord can help diagnose nervous system disease. For pet owners who are not very cost sensitive, these modern medical technologies allow veterinarians to treat causes of seizures that only a decade or two ago were considered untreatable.
Finally, pets can be victims of epilepsy. This seizure disorder begins early in life and is the most common cause of seizures in pets under five years of age. There is no way to test for epilepsy, so all other causes of seizures must be ruled out. In young animals, the cost of brain imaging often dictates that we assume epilepsy even without completely excluding the other four categories. While incurable, nine out of ten epileptics can be successfully treated with anticonvulsant medications. These medications, including phenobarbital and bromides, require regular monitoring throughout the pet’s life. Newer technologies, including deep brain stimulation, are being explored in animals for patients who do not respond to traditional therapies.
If your pet is having seizures, please keep a log of how frequently and how long they last. Make an appointment to see your veterinarian as soon as possible. Be sure to carefully describe what you are seeing to help your veterinarian determine if the convulsions are indeed a seizure or just something similar. Videos taken on a mobile phone are a great way to document these events for your veterinarian.