I just received an e-mail from a site on canine epilepsy. I was told that one of the possible causes of epilepsy could be overvaccination. Here's part of the e-mail and then some links for more information. Hope it helps to clear things up. ~Jojinator 
"Please keep in mind that vaccinations given too frequently or overvaccination in general, is not only unnecessary, but may cause seizures and trigger or aggravate immune related diseases, such as allergies and thyroid problems. We often see dogs and puppies react to vaccinations by having one or several seizures. In some cases, the dog's overall health will improve when the vaccination boosters are discontinued.
You may be interested in knowing that there are many advocates who advise against overvaccination, and who are advocating less frequent vaccinations because they are overused, and are needlessly causing a host of illnesses in our dogs, including epilepsy.
So, please speak to your Vet about running titers on your pup to be sure that there is immunity, rather than endangering your pup with more vaccinations. If your pup has had the required puppy shots and boosters, I see no reason to vaccinate any further. In the US and Canada, if one runs titers as proof of immunity, (including rabies), and the levels are adequate, you can avoid the boosters, and again, this *includes* rabies.
You may read more about the latest on vaccination protocol (some of which has been written or quoted by leading Veterinarians), and titers at the following Guardian webpage: "
http://www.canine-epilepsy-guardian-...nnual_vacs.htm http://www.canine-epilepsy-guardian-...ne_Article.htm http://www.canine-epilepsy-guardian-..._protocols.htm http://www.canine-epilepsy-guardian-...techTiters.htm