Zonisamide -25mg 100 count bottle for Pets | GenericZonisamide is an antiseizure medication that may be useful as an add-on drug for refractory epilepsy. Zonisamide can be used together with phenobarbital and/or potassium bromide for treating seizures, incases where your dog's seizures are not adequately controlled while taking phenobarbital or potassium bromide alone or combined. . Zonisamide -25mg 100 count bottle for Pets | Generic. Sold by Vet Approved Rx.