My dog farts alot. is this normal?

One of my dogs could peel paint off a wall with her gas. Diet can play a big part in this, but so CAN the breed. We feed Merrick, which is a very good food, but I didn't mention that this *stinker* is a Bulldog.....so, pretty normal for her. Our other little dog eats the same brand of kibble and has NO gas.