Our pets suffer from allergies much like us humans. Allergies usually fit into two categories: seasonal and nonseasonal. Grass, trees, mold and pollen are seasonal allergies whereas dog food is a nonseasonal allergy. Signs of allergies might include any one or more of the following: itchy skin; chewing and licking of the feet; watery eyes; nasal and eye discharge; chronic ear infections; scratching; or chewing. Hypoallergenic shampoos use ingredients that are less likely to cause an allergic reaction, and do not include fragrance or cologne.