What Is Allergic Dermatitis?
Allergic dermatitis also referred to as atopy and atopic dermatitis is the predisposition to allergic disease in response to environmental allergens. Although the house dust mite is one of the most common sources of allergens causing atopy, fleas and other parasites are capable of triggering similar reactions.
Most allergic pets do not start with severe itching. Veterinary dermatologists recognise that certain breeds are predisposed to develop allergic skin disease and that the tendency to develop atopy is often inherited.
Susceptible Dog Breeds
Breeds with a high incidence of allergies include the:
- Belgian Tervuren
- Boston Terrier
- Cairn Terrier
- English Setter
- Golden Retriever
- Irish Setter
- Labrador Retriever
- Lhasa Apso
- Miniature Schnauzer
- Scottish Terrier
- Shih Tzu
- West Highland White Terrier
- Wirehaired Fox Terrier
Signs & Symptoms
Many dogs with chronic allergy develop pink, red, bronze or dark skin. The bronzing color is from pigment in the dog’s saliva that discolors the skin and the hair. Foot licking, recurrent ear inflammation, face rubbing, itching of the armpits and groin in a young animal is very suggestive of atopy.
Staphylococcal bacteria infect the skin, causing papules (small red bumps) or pustules (small pimple-like lesions). Scabs can also form when the papules or pustules rupture. Secondary yeast infections are common in allergic dogs. Dogs become itchy, and skin develops greasy yellow scales with an unpleasant smell.
Diagnosis of allergies is a complicated task and usually involves various tests, such as skin scrapings, fungal cultures, and blood tests. However, the investigation of a suspected allergic dog includes rigorous treatment for external parasites and secondary bacterial and yeast infections, which often complicate and contribute to the itch.
A diagnosis of food intolerance is made in 2-10% of dogs with intense itch. Food allergies can be controlled without using drugs and are worth ruling out by introducing an elimination diet, followed by a dietary challenge to confirm the diagnosis.
Elimination diets are time-consuming and require considerable owner commitment. It can be up to 3 months before the dog stops scratching. Once other causes of itch have been ruled out, specific tests to detect allergic antibodies to environmental allergens can be undertaken to confirm the diagnosis of atopy.
Conventional And Natural Treatments
Conventional therapy for atopic dermatitis relies on corticosteroids and antihistamines. Corticosteroids can be given by injection, by mouth, or by both routes. The most commonly used corticosteroids are prednisone, prednisolone, dexamethasone, and triamcinolone. While very effective when used to control itching and inflammation, corticosteroids have both short-term and long-term side effects.
Short-term side effects include increased water intake, increased urination, increased appetite, and destruction of joint cartilage.
Long-term side effects are numerous and include suppression of the immune system, infections, diabetes, liver disease, joint problems, obesity, glaucoma, cataracts, high blood pressure and stomach ulcers. When needed, short-term use of fast-acting corticosteroids is preferred. Depot injections are not usually recommended for dogs but are commonly used in cats.
For the above reasons, holistic doctors prefer not using steroids for long periods of time unless it is absolutely necessary. In pets with allergy, antioxidants, fatty acids, hypoallergenic shampoos and conditioners and herbal remedies can decrease itching and inflammation. Principal natural treatments include topical decontamination with frequent hypoallergenic shampooing and conditioning, omega-3 fatty acids, and natural diet.
The frequent use of hypoallergenic shampooing and conditioning is vital in removing foreign proteins from the skin and coat of allergic dogs. Shampoos and conditioners with aloe vera and colloidal oatmeal are usually tried first and work on most pets if they are bathed every 24 or 48 hours until itching decreases. If these products do not help decrease itching, medicated products containing antihistamines or corticosteroids can be tried.
Omega-3 Fatty Acids
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – are derived from fish oils, algae and flaxseeds. Omega-3 fatty acids are beneficial by regulating the production of chemicals causing inflammation (prostaglandins). DHA is required for proper mental and visual functions. Large doses (2 to 4 times the label dose) have been shown effective in treating allergic dogs and cats. Fatty acid supplements often allow doctors to lower the dosages of corticosteroids or non-steroidal medications.
Feeding natural, holistic diet is recommended for several reasons:
- Some pets experience a dramatic improvement in their skin disorders (less itching, less flakiness, less redness, less body odor etc.) when fed a wholesome diet free from additives, chemical preservatives and hormones. Many commercial pet foods are processed at temperatures higher than 400°F, which increases the level of trans-fatty acids.
- Common artificial preservatives used in commercial pet foods, such as BHA, BHT, sodium metabisulphite can cause liver and kidney problems and brain damage in people. While the use of these chemicals has not been proven to cause specific diseases in pets, there is no confirmed data on whether or not they may cause chronic skin diseases when ingested long-term. Therefore, whenever possible, the most healthful alternative is to use the natural diets that do not contain these chemicals.