Vail Pet Talk: What do you do if your pet is having seizures?
VAIL CO, Colorado
A seizure, fit, or convulsion is defined as an uncontrolled, transient electric discharge from the neurons in the brain. Most seizures are due to epilepsy, which means there is no underlying disease in the brain. You may have heard from your veterinarian or doctor that epilepsy is a disease of “rule outs,” which in plain English means: “If we can’t find any reason for the seizures we call it epilepsy.”
Epilepsy is controlled and not cured. The medications, called anticonvulsants, most commonly used in animals are phenobarbital and potassium bromide. The most common reason the anticonvulsants fail is human error:
“The most common reason … is improper administration of the medication,” writes veterinarian Cheryl Chrisman in “Small Animal Neurology.”
Often owners and veterinarians are to blame for this problem. Dr. Dorothea Schwartz-Porsche writes in “Current Veterinary Therapy” that some of the factors responsible for inadequate control of seizures are: “improper choice of drugs, insufficient drug dosage, too rapid change of medication/dosage and noncompliance.” Most veterinary neurologists would agree.
So what do you do if your dog or cat is having seizures? Your veterinarian will want to try to rule out other diseases/causes for the seizures. Part of his/her evaluation will include a complete blood count, serum chemistries, thyroid tests, urinalysis, and skull xrays; additionally they may recommend an electroencephalogram (EEG) and cerebrospinal fluid analysis (CSF tap). You may be referred to a neurologist for the EEG and CSF tap.
If all the tests are normal and epilepsy is diagnosed, you and your veterinarian have some decisions to make. As a rule of thumb anticonvulsants are not started unless the seizures are very severe, occur in clusters, or occur more often than once a month. Some owners cannot handle seeing seizures and this is considered a valid reason to start therapy. A good relationship with your veterinarian is crucial; several attempts with various drugs and doses may be required to control the seizures. Keep a diary or log; keep information about time and dose of drugs administered, mood of patient/side effects, and any seizure activity.
Phenobarbital is usually the first drug selected for dogs and cats; it is relatively inexpensive and rapidly effective (usually within 2 to 3 days). Some side effects include sedation, hyperactivity, and increased thirst/urination. Once it is started animals often develop a dependence ib the drug. Two to three weeks after it is started, your veterinarian will check blood levels to determine if you are achieving the therapeutic dose; this, along with serum chemistries to check liver function, should be performed every six months. Valium or Diazepam is not effective as a single agent in dogs; it is, however, used intravenously in dogs and cats to arrest status epilepticus (i.e. a long, protracted seizure).
If one of these drugs does not control the seizure another “first choice” drug should be chosen rather than combining two drugs. One drug should slowly be discontinued while the other one is slowly added; sounds fun doesn’t it? If this doesn’t work, we go to combination therapy. If combination therapy is not successful there may be an underlying cause that was not present on the initial examination such as a progressive encephalitis or a brain tumor; reevaluation may be necessary. As a last result your veterinarian may want to try some human drugs; unfortunately, many of the doses for animals for these drugs is guesswork so there is some risk.
As you can see, controling seizures can be difficult. It can also be quite easy and uneventful. The important factor is the human factor: you and your veterinarian. Keep open a good line of communication with your veterinarian. Keep in mind that we are not going to cure the seizures but rather control them; an occasional seizure is bound to happen, so be prepared!
Dr. Stephen Sheldon, practices at Gypsum Animal Hospital. He can be reached at 970-524-DOGS or by visiting the clinic website http://www.gypsumah.com.