It could be the protien source, or the brand of food. Chicken & Lamb both are high allergy proteins.
Low grade dog foods change their protein sources constantly, so no two bags are the same. Purina is an awful dog food, especially for a bulldog. Unless you learn more about dog food, you could have no idea- because they market their food and tell you how wonderful it is. But I am on a personal mission to teach dog lovers to feed good dog food- you will be amazed at the difference in your dog. Not only the food, but the treats and snacks are important too.
Please check out this topic, it sheds some light about why I don't like purina, because I don't want you to feel like I am being bossy or trying to force you to do anything. The main ingredient is Corn, so basically you are feeding your dog mostly corn everyday. Then they also list Corn Glueten meal, which means more corn in a different form. Then Soybean meal, a cheap way to put protein in dog food. Well, I will stop there and let you read the topic:
http://www.englishbulldognews.com/f...utrition/2931-why-i-hate-purina-dog-food.html
Here is the dog food ratings. Also these are our recommended dog foods but there are many other great choices, those are just our personal choices.
Also, do you use plastic, ceramic, or stainless for a food dish?
Your bully is adorable, lets get him all better!