Allergies are a major cause of skin disease, discomfort and distress in dogs. Pruritus, or intense itching, is the most characteristic sign of allergies. This itching is caused by the release of histamines from mast cells located throughout the body. Hair loss, redness and skin infections may result secondary to the allergy. Over time, the hair coat may become stained from excessive licking and the skin may become dark and thickened. Ear infections may also result from allergic conditions. The two most common types of allergic conditions exhibited by dogs are those of inhalant allergies and food allergies.
The treatment of allergies can be achieved by using three methods: removal of the allergen source, suppression of the itch with antihistamines or corticosteroids, and desensitization of the immune system to the specific allergens affecting the pet. The removal of the offending substance is appropriate if the allergen source is a food item, flea saliva, or something that is easy to remove from the environment. Elimination of certain diets and food trials are often implemented if food allergies are suspected. If flea bites are the problem, it will be necessary to eliminate fleas on the dog. Your veterinarian will suggest the appropriate flea treatment for your dog. Many allergens, however, are difficult or impossible to remove, such as pollen in the air or dust in the home.
The use of antihistamines or corticosteroids is the second method. Antihistamines act by reducing the release of histamine by the mast cells and are often very effective in controlling allergy symptoms. Corticosteroids act in many ways to suppress the allergic reaction before and after the allergy develops. Steroids are very effective, but must be used with caution. If used excessively, adverse effects can be seen. Because of the often-extensive self-trauma associated with allergic conditions, antibiotics or antifungal agents are often administered to control the secondary infections that are frequently present.
A newer treatment option for allergic pets that do not respond well or cannot tolerate steroids is available. Cyclosporin (Atopica) is an immuno-modulating drug that can significantly reduce symptoms. It is FDA approved for this purpose, and appears to be safe. It is common however, that pets will vomit the drug during the first week of treatment. Vomiting usually subsides, but some patients are not able to take cyclosporine orally.
The final treatment option is the process of desensitizing the patient over time. This desensitization process begins by identifying the allergens that the dog is sensitive to through specialized intra-dermal tests or blood evaluation. Once the allergens are identified, specialized mixtures of these substances are combined into an injectable form that is given at regular intervals. With time, the dogs immune system response to these allergens diminishes and many dog owners note measurable improvement in their pets.