Dogs with Atopic Dermatitis: Causes, Diagnosis, and Treatment
Canine atopy, especially when complicated by pyoderma, can be difficult to
distinguish from flea allergy dermatitis, scabies, demodectic mange, food
allergies, and other skin diseases. The diagnosis can be suspected based on
the history, location of skin lesions, and seasonal pattern of occurrence. Skin
scrapings, bacterial and fungal cultures, skin biopsy, and a trial
hypoallergenic test diet should be considered before embarking on an involved
course of treatment for atopy. It is important to treat and eliminate fleas. The majority of dogs with canine atopy are
allergic to fleas and may have an associated flea allergy dermatitis
complicating the picture.
Treatment: The most effective long-term solution is to change the dog’s
living circumstances to avoid the allergen. The atopic dog is usually allergic
to many different allergens, however, and often it is not possible to avoid
exposure to them all.
Most dogs with atopy respond well to treatment. A first and most important
step is to reduce the threshold for scratching by treating and eliminating all
associated irritative skin problems, such as fleas, seborrhea, and pyoderma.
Wipe the dog down with a damp towel when she comes in from outdoors, which
helps remove pollens picked up in the coat.
Antihistamines control itching and scratching in 20 to 40 percent of atopic
dogs. Corticosteroids are the most effective anti-itch drugs, but also have the
most serious side effects. They are best used intermittently in low doses and
for a limited time. Preparations containing hydrocortisone withPramoxine are
often prescribed for treating local areas of itching. Pramoxine is a topical
anesthetic that provides temporary relief from pain and itching.
Derm Caps and other essential omega-3 fatty acid products derived from fish
oils have produced good results in some dogs. They are used as nutritional
supplements in conjunction with other therapies. A variety of shampoos is
available and may be prescribed by your veterinarian to rehydrate the skin,
treat bacterial infection, and control seborrhea.
Dogs who do not respond to medical treatment can be considered for immunotherapy with hyposensitization. This involves
skin testing to identify the allergen(s) and then desensitizing the dog to the
specific irritants through a series of injections given over a period of 9 to
12 months or longer. Some dogs will require periodic boosters during times when
allergens are heavy.
Some dogs with atopy benefit from switching to a higher-quality dog
food, even if they don’t have a food allergy. And if they are allergic to
house dust mites, they often cross-react with grain mites and will benefit from
a canned food or kibble that has no grain.