The kind of seizure medication depends on your dogs response to the medication. The most routine medications for seizures are Phenobarbitol and Potassium Bromide, with valium being used in the acute phase. Many human seizure medications (such as Dilantin) can cause liver toxicity in dogs and should be avoided.
There are also valuable holistic medications for seizures, but again it depends on the dogs response. I use the Chinese herbal formulas: Long Dan Xie Gan Tang, or Si Miao San, or other herbal remedies occasionally in conjunction with western anti-seizure medication.