Mary,
It sounds like you are doing everything you can at this point. Good
nutrition is a must. Some like to make up their own foods and some of
us use the better grade cat foods like Iams, NutraMax or Science Diet.
Or a combination of both. there are nutriants in real cat food they
must have.
His outside days must be over tho..he can infect other cats. Retest
him with the ELISA in a couple of months. It's possible he might shake
the virus or even that the first test was wrong, it has been known to
happen. But if you want to do the IFA, it won't hurt, that way you
would know for sure. barb