Zonisamide is a drug used to block seizures in dogs who are suffering from epilepsy. It has few known side effects. Zonisamide is often used in conjunction with phenobarbital; for dogs using both, the dosage of phenobarbital may be significantly reduced and even discontinued.
Epilepsy is a disease that effects some dogs, causing them to suffer from recurring seizures or convulsions, much in the same way that humans with epilepsy react. Just because a pet is having a seizure, however, does not necessarily mean it has epilepsy. While epilepsy can befall any breed of dog, it's found more commonly among golden retrievers, beagles, cocker spaniels, German shepherds, dachshunds, Irish setters, schnauzers and huskies. It's believed to be genetic and run in certain bloodlines. Likely, dogs with epilepsy inherited it from their parents.
Zonisamide works by blocking voltage-dependent sodium and calcium channels. It also raises dopamine and serotonin levels in the hippocampal and striatal parts of the brain. Side effects seem to be few -- mild sedation, loss of appetite, vomiting and slight loss of coordination in some dogs. In most dogs it decreases the amount of seizures that occur as well as lessens the intensity of the ones that do. This can lead to a better quality of life for the canine.
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