Thanks everybody!

The vet tested for giardia, fecal test, skin scraping (skin eruptions), and some other test that I forgot its name. All came back negative, so he thinks it's colitis. Colitis was brought up a while back by a different forum member, so I wasn't too surprised when he said this. He also said something about inflammation, but I didn't really understand as he does have a slight accent . We were sent home with flagyl, cephalexin, and a medicated shampoo for the skin problems.

Scooby4, I don't know if this bit of info will help but he's been living with us for six years and has been on one brand of food for about six months. He was acting rather lethargic for the few weeks of this month and so we kept him in the house and deck, which is void of all vegetation. He didn't eat anything at all that was out of the ordinary which is why I first ruled out food poisoning. His kibble is kept in the bag it was packaged in and is closed with a clip. As well, it stays in the kitchen cabinet, so I can't see what kind of fumes would denature the kibble (?).

Thanks again for all the info and experiences!