Poor Purdy. Did the vet say what the cause probably was, and what the dangers are of just letting it be? If it was a one-time thing, I'd suspect some kind of neurotoxin. The vallium regimen sounds awfully restricting. Too bad they can't provide a time-release medication. I think cats can have epilepsy - a friend's cat may have had it. I'll ask her (the friend) for info. If my memory is correct, she had to administer prednazone.

In the meantime, I just found these sites via Google: http://www.cs.cmu.edu/People/lowekam..._epilepsy.html and
http://www.manhattancats.com/Articles/seizures.html I only scanned them quickly, but they appeared to be informative.

As tough as it might be to retrain Purdy, for her safety you may want to keep her in at night. I'd hate to think of what a wadi dog could do to her in that condition. Good luck.