Snoring you cant help unless he is overweight. The farting is probably the food actually. Try nutro lamb and rice, he will lose weight and eat less food because it has no fillers like corn that your dog cant digest and farts out. The bad breath is probably due to calculus build up on his teeth. You can have a dental prophylaxis performed (teeth cleaning with fluoride and scaler at the vet) for ~150-200 bucks. I suggest this as it will tack a few years on your dogs life as well as keep his mouf from stinkin.