Hi and welcome to EBN. You can start by going to the Home Page and reading the Dog Food Ratings. It lists all the foods according to a Star rating from 6 Star down to a 1 Star, you want to choose a 4 Star or higher quality of food. A lot of Bullies are allergic or sensitive to chicken based foods, and also to grains, so try to choose a chicken and grain free formula. But every Bully is different and what works for one doesn't always work for another. It's really a trial and error process when trying to find a food that your bully will tolerate. A lot of members, including me feed their bullies Fromm's dog food. I feed our two guys the Fromm's Beef Frittata, as my female Blossom is allergic to chicken and salmon. When you are switching to a new food it is best to do a slow transition over two weeks so they don't get an upset stomach or diarrhea. Also it can take up to a month to see any improvement to or benefits from the new food, as it can take this long for the old food to leave their systems.