Treatment & Prognosis for Atopy in Dogs
Goals of Treating Atopy
The goals of treating this common and frustrating canine skin condition are to eliminate or minimize the dog’s exposure to offending allergens, resolve skin sores and infections and restore a comfortable quality of life.
Most atopic dogs are treated as outpatients. A treatment protocol will be selected based on the cause of the dog’s atopy, the seasonality of its symptoms, the distribution and severity of hair loss and skin sores, the presence of any secondary infections, the existence of any concurrent medical problems, client commitment and compliance, and financial considerations. Because atopy usually is progressive, rarely goes into remission and cannot be cured, lifelong management is essential.
The first therapeutic step is to remove any known sources of itchiness, such as fleas, ticks, mites, lice, food ingredients that the dog is allergic to and any other identifiable skin irritants. Dogs with mild atopy often can be managed with oral antihistamines and fatty acid supplements derived from fish oils. Antihistamines can cause drowsiness, lethargy, anorexia, vomiting, diarrhea and/or nervousness. If the dog has secondary skin infections, antibiotics or other medications may be helpful. Shampoos and other topical preparations are often used to soothe and rehydrate inflamed, irritated skin and provide temporary relief from itching and pain.
When atopy is severe and chronic, the veterinarian may recommend a course of oral corticosteroids. Steroids are extremely effective at controlling the itchiness associated with environmental allergies and breaking the itch-scratch-itch cycle. However, long-term steroid use has side effects, and treatment should be tapered to the lowest dosage needed to control the dog’s symptoms. Cyclosporine has also proven effective in controlling itchiness associated with severe atopy, because it suppresses the immune response. Cyclosporine treatment is quite expensive, especially for large-breed dogs, but can cause vomiting and diarrhea. A combination of steroids and antihistamines often controls itchiness more effectively than either drug alone, and at much lower doses.
Allergen-specific immunotherapy, also called hypersensitization (ASIT), is typically reserved for dogs that don’t respond adequately to other forms of medical management. For example, ASIT may be appropriate when oral steroid treatment needs to be avoided or reduced, when symptoms last longer than 4 to 6 months despite other treatments, or when traditional anti-itch therapies aren’t providing enough relief. ASIT involves giving a series of subcutaneous injections, at gradually increasing doses, of those substances that the dog reacted to on its intradermal allergy tests. The goal is to desensitize the dog’s immune system to the environmental allergens that are causing its skin problems. This can take 6 to 12 months, and sometimes longer. However, reportedly it is effective in about 70% of canine atopy cases.
Elizabethan collars, bandages, Tee-shirts, sweat shirts and booties can help reduce self-inflicted trauma, although none of these will relieve the dog’s itchiness. Dietary changes may be appropriate in some cases.
Atopy cannot be cured but it usually can be controlled to a tolerable level. Twice yearly veterinary check-ups are important to long-term management, especially for atopic dogs on prolonged pharmaceutical therapy.