
Hi,
I have no personal experience with epilepsy in dogs, but I do have an old dog & a pup.
My old dog is 14 years old (neutered male lab cross), he's deaf, blind in 1 eye, loosing the sight in the other eye and has a withered back-end with limited mobility (believed to be from HD, we got him from a shelter at 4 yrs old, and later found out that he has had an opperation to remove the hip joint in the top of 1 hind leg - so effectively that leg is only held in place with muscle).
Any way, we got a Mastiff puppy 5 months ago (male). It has been a new lease of life for the old dog, he did take a week or to to really come-round to the idea. The only thing that needs watching, is due to the size of the puppy (who's getting on 9stone) play time can be a bit too much for the old boy. I wish I had got a puppy a few years ago, they have so much fun together :)
Gentle introductions are the best way to elliviate stress for you current dog. We kept our puppy confined to the kitchen for the fist 2 weeks, only leaving the kitchen on-lead, so there was no chance of him being to much for the old dog to cope with.
I really don't think your dog is too old for you to get a puppy :)