Atopy in Dogs

Present in an estimated 10% to 15% of dogs, atopic dermatitis causes not only an irritating itch and reddened patches of skin, but many other secondary symptoms as well. These can include ear infections, bacterial skin infections, and other skin issues that are exacerbated by the self-trauma of inflicted dogs trying to scratch that itch. Diagnosis can be difficult, but once an allergy has been found, treatments can usually help to manage the symptoms.

Atopy, or atopic dermatitis, is itchy skin that is caused by an allergic response to an inhaled environmental allergen. Atopy is the second most common allergy in dogs, after flea allergies.

• Itching on affected skin areas, frequently face, ears, feet, armpits, front legs, and abdomen
• Reddened patches of skin
• Lesions on affected skin areas
• Raised pimples or swellings on affected areas

Secondary symptoms from your dog’s self-trauma to stop the itch of atopy can include:

• Excoriation, or the constant picking at skin
• Fur stained from saliva
• Scale formation on skin
• Alopecia
• Patches of leathery skin
• Hyperpigmentation, or darkened patches of skin
• Hemorrhagic crusts
• Skin infections, such as Staphylococcal and Malassezia, a type of yeast that lives on the skin
• Ear infections

There is one primary cause of atopic dermatitis in dogs, which is exposure to allergens. Some breeds may be predisposed to atopic dermatitis. These include:

• Golden and Labrador Retrievers
• Chinese Shar-Pei
• Wirehaired, Scottish, Boston and West Highland Terriers
• Dalmatian
• Boxer
• Lhasa Apso
• Shih Tzu

The diagnosis of atopy can be difficult because many of its symptoms are typical of other conditions, such as parasites, food allergies, flea allergies and microbial infections. Consequently, the diagnosis of atopic dermatitis is often in conjunction with ruling out these other conditions.

Many factors are taken into account, such as if the onset of symptoms started before your dog was 3 years of age, the symptoms that are present, and medical history. 

If an environmental allergy is suspected, allergy testing can be one of two ways. Intradermal testing involves injecting a small amount of different allergens into the skin of your dog to see if one produces a response, meaning your dog is allergic to it. A serologic test, also called an IgE allergy test, will look for the presence of certain antibodies in a blood sample, which can determine a specific allergen.

Atopic dermatitis can be a lifelong condition that generally cannot be cured. But there are many ways to treat the symptoms and lower your dog’s allergic response. Treatments are often done in combinations to strengthen their results, such as one main core treatment along with supporting treatments.

Core Treatments

Immunotherapy is the only treatment that can cause symptoms to go into remission, and in rare cases, can possibly cure the allergy. This involves multiple injections or drops with increasing levels of the allergen to increase the immune system’s tolerance of that allergen. This treatment seems to work best for those dogs with a seasonal atopic dermatitis. In very rare cases, anaphylaxis can occur.

Cyclosporine is a drug that is most often used in organ transplants to prevent rejection. For allergy sufferers, it can help modulate the immune system. As an immunosuppressive agent, cyclosporine inhibits the activations of immune cells, thus stopping the allergic response that causes symptoms. Side effects of this drug may include diarrhea and vomiting.

Other drugs that may be prescribed to suppress the itch of atopy are Oclacitinib and CADI.

Supportive Treatments

If a specific allergen has been identified, avoiding or limiting exposure is the best way to prevent an atopic reaction.

Controlling the itch of atopy can be done in a number of ways. Antipruritic drugs may be prescribed, which may include otic corticosteroids for ear infections, topical hydrocortisone or triamcinolone sprays, or oral steroids. Omega essential fatty acids may also be recommended, as can oral antihistamines.

Bathing can not only combat the itch, but can also improve the skin barrier, causing less of the allergens to make their way in. Use shampoos and leave in conditioners that are antimicrobial, antibacterial, antipruritic, and contain ceramides.

Treatment must also include treating any secondary conditions, such as microbial and bacterial infections. Antibiotics or antifungal medications can be prescribed for this reason.

Once you and your veterinarian have decided on a treatment plan, implementation may take many treatments over a lengthy amount of time to be effective. Any core treatments will likely need multiple visits to the clinic, and can include at home oral or topical dosages. Monitor your dog and report any flare-ups of symptoms to your veterinarian.

Supportive therapies will mostly be done at home, and can include antibiotics, oral antihistamines, topical medications, and medicinal baths. Topical lipid skin treatments containing ceramides can help to repair damaged skin. A diet high in omega essential fatty acids has been seen to relieve symptoms.

Limiting or preventing exposure to the allergen can be difficult, but is the best way to stop the atopic dermatitis from reoccurring once is has cleared. Wiping off the feet and other exposed skin areas after outside contact with a damp cloth or antibacterial wipes can reduce an allergic reaction.