Epilepsy study UK
The Royal Veterinary College are doing a study on the "Influence of a Diet on Improving Seizure Control in Canines with Idiopathic Epilepsy". Info here http://www.rvc.ac.uk/CIC/Current/Neurology.cfm you would need to be able to travel to Herts, it involves free consultation, diagnostic testing and 6 months supply of food.
Little Joe might have qualified for this study a year or so ago. Until January 2012 he was having every increasing cluster fits, diagnosed as idiopathic and arguable brought on by stress.
Then my vet suggested Skullcap and Valerian tabs. I give him 4 tabs every morning (made by Denes Veterinary) and the fits have stopped.
A human sufferer also told me never, ever, give an epileptic of any kind EPO, so I have been really careful ever since, as I had been giving Rebel a capsule every day and he had what looked like a petit mal episode a couple of times. The vet wasn't sure whether these episodes were due to his SM, the medication or old age, but since stopping the EPO he has been absolutely fine.
I gave my idiopathic epilepsy Cavalier the Scullcap and Valerian tabs, sadly they didn't help her [although we now suspect that her seizures may have been caused by the chronic carbon monoxide poisoning :(]
Denes are an amazing company and have veterinary approval for many of their medications, including this one.