Allergic Disease in Dogs and Cats
The most common allergy in dogs and cats is flea hypersensitivity. This means that the affected pet has an allergic reaction, involving the skin of the entire body, to the saliva of the flea. Unfortunately for pets affected with this, all it takes is one bite from one flea and they can be as itchy as a person covered with poison ivy! Fortunately for our pets, there are many products available to prevent them from being bitten. These are products available from your veterinarian that work very well to prevent fleas from biting your pet.
The second most common allergy in dogs and cats is atopy. This is a general term that includes allergic skin disease caused by any inhaled allergen. Inhaled allergens are the same things that cause humans to suffer from seasonal allergies. Inhalant allergies usually start out as a seasonal problem, but as time goes by, they tend to persist year-round. Examples of allergens that cause atopy are: house dust mites, pollens from trees or grasses, and molds. Obviously, these things vary by location. Pollen that is common in Missouri may never be a problem in Arizona.
The above two types of allergies are commonly diagnosed using intradermal (skin) testing or serologic (blood) testing. Intradermal testing requires a visit to a veterinary dermatologist (a veterinarian that specializes in skin problems). It involves shaving hair from the dog or cat (varies as to where the pet is shaved), drawing a grid, injecting a different allergen in each square on the grid, and grading the reaction of the skin to each allergen. The serologic testing involves drawing a blood sample and submitting the serum (liquid portion of the blood) to a laboratory that performs the test. The result of both types of testing is a list of allergens that the pet is sensitive to. From this, serum is made to administer to the pet in increasing amounts until hyposensitization is accomplished. This will diminish the pet’s response to the allergen.
Veterinary dermatologists estimate that adverse food reactions account for only 1-6% of all skin diseases seen in general practice. Food allergy is thought to make up only 10-20% of all cases of allergic skin disease in dogs and cats. Of these cases, up to one-third of them occur in animals less than one year of age. In many cases of allergic skin disease caused by a food ingredient, the only symptom is an ear infection affecting both ears. Food allergies are not typically diagnosed using intradermal or serologic testing. They are typically diagnosed, and treated, by using an elimination diet. This means that the pet is fed a diet with known ingredients and not given any other foods (treats, snacks, rawhides, etc). The trial should continue for a minimum of 3 weeks. After 10 weeks, if there is not an improvement, a different diet should be selected. The culprit in food allergies is most often the protein source. That’s why prescription diets for allergic pets have unusual meat sources, such as venison, duck, or fish. No food is “hypoallergenic” except for ones with hydrolyzed (man made) protein. They simply offer a novel protein source that the pet has not been previously exposed to. Lamb and rice diets that are available over the counter are not true “allergy” diets as they may contain other protein sources in addition to lamb and rice. Beware of this if your pet truly does have a food allergy. They are appropriate, however, for dogs and cats that seem to be sensitive to diets that contain some other protein as the primary protein source.
To sum it all up, itchy dogs and cats may have one of several types of allergic disease. The above information is just a highlight of information about allergies in pets. There are many effective treatments available today. Working closely with your veterinarian should help you discover relief for your companion.
Please note that this information does not replace onsite, professional, veterinary care. It is solely for educational purposes. Your pet's medical condition should be evaluated by a veterinarian before any medical decisions are implemented. If there is a potentially life-threatening emergency involving your pet, take your pet to a veterinarian or veterinary facility immediately.
Veterinary Technical Services Department