Common symptoms in allergic cats are pruritus, asthma / respiratory symptoms, acne, sneezing, watery eyes, ear infections, vomiting and diarrhea. If the cat is already suffering from asthma, environmental allergy often worsens the discomfort. Feline atopy is under-diagnosed, because a common symptom of atopic dermatitis in many cats is over-grooming, which is mistaken for normal behavior or anxiety.