Definitely stay away from Milk Bones

Give frozen carrots or frozen green beans, or get some holistic grain & chicken free treats. Carolina Pet Pantry has those.
My boy Tidus is allergic to chicken as well. I give him Fromm Beef Fritatta, which you can get from petflow.com (it is not sold at pet retailers like petsmart)
Maybe you could try that one. Fromm is one of our recommended dog foods, for many reasons. Human Grade meat, natural vitamins (not synthetic), and Enzymes and Probiotics in the Guaranteed Analysis. It is higher in protein, however, so make sure your bully gets a bit of exercise each day to burn it off. Here is the ingredients:
Beef, Peas, Whole Dried Eggs, Potatoes, Pea Protein, Pork Meat Meal, Beef Liver, Sweet Potatoes, Tomato Pomace,
Salmon Oil (preserved with mixed tocopherols), Flaxseed, Cheese, Safflower Oil (preserved with mixed tocopherols),
Vegetable Broth, Whole Eggs, Carrots, Broccoli, Cauliflower, Apples, Green Beans, Lecithin, Pork Cartilage, Potassium
Chloride, Cranberries, Blueberries, Salt, Chicory Root Extract, Alfalfa Sprouts, Yucca Schidigera Extract, Folic Acid,
Parsley, Lactobacillus Acidophilus, Bifidobacterium Longum, Lactobacillus Plantarum, Enterococcous Faecium,
Vitamin A, D3, E, B12 Supplements, Choline Bitartrate, Niacin, Pantothenic Acid, Ascorbic Acid, Riboflavin, Thiamine
Mononitrate, Pyridoxine Hydrochloride, Biotin, Zinc Sulfate, Ferrous Sulfate, Manganous Sulfate, Copper Sulfate,
Cobalt Carbonate, Calcium Iodate, Sorbic Acid, Iron Proteinate, Zinc Proteinate, Copper Proteinate, Manganese
Proteinate, Sodium Selenite.