I have a bullmastiiff that has little bumps on him.Vet told me that it's not fle!

I have a bullmastiiff that has little bumps on him.Vet told me that it's not fleas but allergies, anyone know?

The vet told me that he probaly has an allergy to something. Tried steroids and benadryll, didn't work. Switched his food, didn't work. Took him off of Frontline, didn't work. Does anyone know what they could be? Heat rash? Allergic to grass? He doesn't really seem to be bothered by them, doesn't itch them or anything but I am concerned not only for his health but it also looks bad.

Hi there I had a bull mastif/sharpei x thst was allergic to ertain grasses, Didnt look good, but she was happy. I gave her coat a really light cover of olive oil on her coat and it seemed to fix it. just watch out if you do this and have furniture that your dog is allowed on..