There are several alternative immunotherapy / desensitizing techniques for allergies which use very small doses of allergens along with an enzyme. The doses used are the same or smaller than the doses used in diagnostic skin prick testing.
Enzyme Potentiated Desensitization (EPD) - also known as Low Dose Immunotherapy (LDI) - was developed in England in the 1960's and is widely used in Europe.
Low Dose Antigen (LDA) Therapy was developed and is used in the United States. A 200 study involving twenty-seven dogs with confirmed atopic dermatitis found no evidence that lose-dose allergy shots are more effective than standard-dose allergy shots.