My dog is CONSTANTLY farting. HELP!?

He is a husky/akita mix, neutered, 18 mos old. My other dog is a german shepherd. They both seems to be farting more than normal since switching them to Eukanuba dog food. It is the large breed formula. I understand that switching food will upset their tummies but they have been switched for 2 months now. Would it make a difference to switch them to a sensitive digestive systems formula? He is really killing us here, his farts are lethal, theyre are not normal "gy dog" farts