Our Baby is sick

Our pet dog, Maxi has been sick for the past two weeks! He has been vomitting once or twice, every other day. Not much though, but enough to worry and make us 'first-time parents' very anxious. Took him to the vet a couple of times and diagnosed as gastritis with too much acidity in his stomach. Followed up with occasional telephone calls to the vet to keep him updated on Maxi's condition and get some advice. The vet told us to try to keep our backyard (that's Maxi's 'domain' where he's king and roams freely) very clean and our plants beyond his mouth's reach. He's very inquisitive and nosey over his surroundings and likes to sniff and eat whatever, be it edible or inedible - insects, leaves, roots, soil, charcoal, etc.!!!
Feeling very helpless in this situation because we had him only since 1st October, 2005 and we sort of know next to nothing in giving him the best care. Will have to do some homework surfing the net for more answers!!