Allergies, also known as atopy, are very common in dogs. They are due to allergens being absorbed through the skin, ingested and/or inhaled. Common allergens include food proteins, tree and grass pollens, weeds, molds, house dust mites and fleas. It has been estimated that 15 percent of the dog population is affected and any breed may be involved. It is considered to be an inherited skin disorder. The age of onset is usually between 6 months and three years of age. Dogs typically show signs of excessive itchiness, chewing on paws and rubbing their face. Other skin and ear problems may be present along with atopy and should always be treated concurrently.
Atopy usually starts out as a seasonal problem and will progress to a year-round disorder. Many dogs will show variation in their itchiness, however, at different times of the year. Our goal is to keep the itch level tolerable and prevent secondary problems.
Allergies are not cured; they are only controlled and can be a life-long problem.
Management of atopic dogs is a challenge and you, the owner, need to be committed to helping the dog through trial and error. In the past, almost every dog was treated solely with corticosteroid drugs, such as prednisone, or methylprednisone to help stop the itching. Corticosteroids are very effective for this purpose. They are a double-edged sword however and may cause many short and long-term side effects. The mildest side effects include increased drinking and urination. Most healthy, housetrained pets will accommodate this with no problem. As the length of time that the dog is on the corticosteroid increases, more and more effects will be noticed. Long-term use of steroids can lead to hair coat abnormalities, increased infections and Cushing’s Disease or hyperadrenocorticism. To avoid serious complications from treatment of allergies, we often use multiple strategies to control itch, infection and adverse effects.
- Reduce allergen load: By preventing unwanted allergen exposure, we can help reduce the level of itch. Use of bathing, foot rinses, prescription hypoallergenic diets (if food allergens are an issue) and avoidance of environmental allergens can be beneficial in most cases.
- Topical therapies: If your pet has localized itch, infections or dermatitis, topical control with steroid-containing medications can be useful. Sprays, lotions, creams, ointments are all available when needed.
- Systemic therapies: Depending on the itch level, various medications are used to control itch and provide relief from generalized skin involvement and infection. These may be antihistamines, steroids, immunosuppressive drugs, monoclonal antibody therapy, hypoallergenic diets and injectable anti-itch drugs. In addition, secondary infections may require antibiotic therapy.
- Treatment of the underlying allergy: Many dogs that are facing a life-time of recurrent symptoms and infections are best handled with a referral to a veterinary dermatologist for a consultation and allergy testing. Once the problematic allergens are identified, then hyposensitization injections can be started. This reduces the number of other drugs that are required to manage the allergy condition.