We have only had one occasion when a client developed allergy sysmptoms while playing with our puppies.  In that case the child was allergic to the saliva, not the dander or dog hair.  Our dogs are very intellegent and learn quicly not to lick people when trained.  Other than training I don't think there is an anwer to a saliva allergy.  Even clients who have been forced to give up previous pets due to a dander or hair allergy are not allergic in the least to our dogs.