Poor you. I know exactly what you mean with the farts! I do have the solution. put them on the barf diet! I have minibulls and I raise my puppies on it too. When they go to their new homes sometimes the new owners are not comfortable with it and put them on 'complete foods' and the next thing they are sending me posts because they are being gassed! Once they return to the barf food the air clears. Bull breeds seems very inclined to be gassy. I have heard that the next best thing to Barf is royal canin. Have not tried it myself. I'd stay away from the pal for bullies or buy gas masks! Best of luck.
