My Boyfriend is Allergic to My Dog?

It may be brutal, but I think he will eventually get over his allergies. I have no actual research to back this up, other than my mom and I used to be really allergic to cats. We brought in a stray anyways and for a couple weeks our allergies were really bad, but then through continued exposure neither of us are allergic to cats anymore. The same thing happened to my roommate's boyfriend.