Thus, an animal who is only slightly allergic to house dust and to the pollen of a Spring-blooming plant may manifest allergic skin disease only in the Spring when both allergens occur, raising the immune system s response over the threshold at which clinical signs are seen. Since allergy may be inherited, affected animals should not be bred. Contact dermatitis is best treated by eliminating the causative substance from the pet s environment, if possible. While pollen allergies typically begin with a seasonal pattern, after several years the skin disease may persist year 'round in severely affected animals. Allergies to molds are typically more severe during wet weather when molds flourish, while allergies to house dust, cotton and wool tend to be year round.
Diagnosis requires skin testing or a blood test.
Skin testing, the more reliable method, is done by a veterinary dermatologist. A substance to which the pet is allergic will produce a red bump, the size of which indicates the degree of sensitivity to the specific allergen. Antibiotics, topical medications and therapeutic shampoos should be discontinued at least 7 days before skin testing. Thyroid medication should not be discontinued. If the skin is so inflamed that a skin test cannot be done, a blood test can be performed.