Help, my boy's barfing too much

[engsohere]

Thanks for the reply...

I'm not sure of his age, maybe two no older than three. I took him in as a stray about a year ago. He drinks about 8-10 times a day, and not just little sips, sometimes he drinks up to a minute. Yes, I only feed him the Soild Gold dry food. Just for reference...

Jan 08, barfed 1st, 15th, 18th, 21st
Feb 08, barfed 7th, 29th
Mar 08, barfed 3rd, 10th, 29th
Apr 08, barfed 2nd, 25th

Sometimes there's very little hair in his vomit, but he's a DSH so I doubt that's an issue. On the other hand, he's really been shedding alot so that could make sense. Right now I'm leaning toward the warmer weather as the cause, but this is a first for me so I can't say for sure. Here are a few pics...