Dog farting? Dog got bad gas? Here's your cure: Dinovite
"So your dog has the ability to clear a room, peel paint and make a
pig blush. Why does he have such bad gas? Well, in a nutshell he
probably is not digesting his food thoroughly. And these partially
digested items are resulting in the bad gas problem."
[Excerpt from the Dinovite site]
And... if that doesn't do the trick we suggest you try the Dog Fart Thong.
Seriously speaking though, if you do have a gassy canine and would like more flatulence educational information on pooch farts you can find some good info here: http://dogs.about.com/cs/generalcare/a/flatulence.htm
And... if you just feel that you need to see and hear a dog passing gas check out the farting dog scene from this Three Stooges Clip (it's hilarious... about 2min and 30sec into the video)