Is anyone’s lo showing an allergy to pets or specifically dog saliva?

My little guy got watched at a new place last week and now has a rash on his face by his eye. The only difference is she has dogs and even though she knows I don’t want them by his face when I walked in the dog licked the side of his face. I’m goin to see if he can get an allergy test even thought he’s under a year, do they do that?