I can't recall having ever heard Dickens break wind, which is odd, because every other dog I've had has been gassy, particularly after eating chicken. The one difference with Dickens is that he gets almost no carbohydrates except what's in the cup of dog food he gets daily. Apart from that he gets mostly chicken and beef, both raw and cooked.
I really think starches and sugars are the culprits. Lots of sugars, both digestible and indigestible for the little germies in the gut to feast on.