Common Disease Name:
Allergic inhalant dermatitis, atopic dermatitis
Medical Term for Disease:
Atopy- development of skin itching due to environmental allergens. Instead of getting itchy eyes, nose and sneezing like most people do, dogs get itchy skin.
Species Affected by Disease:
Dogs
Age Animal Usually Affected:
Most dogs develop signs of atopy at one to two years of age, with a range of three months to seven years. Signs usually get worse with age, and seasonal itching may become non-seasonal.
Commonly Affected Breeds:
Probably inherited; seen most in beagles, Boston terriers, Cairn terriers, Chinese Shar-pei’s, Dalmatians, English Bulldogs, English Setters, Golden Retrievers, Lassa Apsos, Miniature Schnauzers, Scottish terriers, West Highland white terriers, and Wirehaired fox terriers. Breeds that are predisposed may vary depending on where they live geographically.
Sex Usually Affected:
Both sexes, but females reported to be more commonly affected than males.
Disease Symptoms:
Areas most commonly affected with itching are between the toes, all four feet, muzzle, around the eyes, under the arm, in the groin, and ears. Skin lesions affecting these areas can include redness, hair loss, scales or crusts, red stains on fur from saliva, darkened skin and thickening of the skin. Pustules and circular, sometimes peeling skin lesions are signs of possible secondary pyoderma, usually caused by Staphylococcus intermedius. Often ear inflammation complicated by Malassezia pachydermati and concurrent signs of fleas and flea allergy dermatitis are present in many patients. Excessively oily coats and conjunctivitis can be observed as well.
Method(s) of Diagnosis:
There are two ways to tests for inhalant allergies: Taking a blood sample and sending the serum for allergy testing to detect allergen-specific IgE is commercially available. The second is intradermal skin testing (IDST), which is usually done by a veterinary dermatologist. The advantages of serum allergy testing over IDST are the availability of the test to general practitioners. Disadvantages include frequent false positive reactions and limitations on the number of allergens tested.
Disease Causes:
There is a genetic predisposition in these dogs to the development of skin hypersensitivity to allergens in the environment. The sensitivity is usually to multiple pollens such as grass, trees, weeds, fungal and mold spores, house dust mites, animal dander, and natural fibers.
Treatment:
De-sensitization with allergy shots (immunotherapy) successfully reduces itching in 60-70% of patients. Once allergens are identified with serum or skin testing, these allergens are included in the allergy injections and are administered subcutaneously, in gradually increasing amounts. The response is slow, often requiring three to six months. Corticosteroids should be used carefully in atopic dogs to prevent causing Cushing's disease and associated problems, aggravating skin infections and causing demodectic mites to become active. Prednsisolone may be given for short term relief and to break the itch-scratch cycle. Hydroxyzine, chlorpheniramine and diphenhydramine are anti-histamine, which may give a little relief without causing immune suppression.
Prognosis:
Atopy cannot be cured. Some form of therapy may be necessary for life.
Complications:
Secondary skin infections and concurrent flea allergy dermatitis are the most common complications of atopy. These dogs can also have reoccurring ear infections or inflammations and food sensitivity. Often they will be placed on a skin diet as well.
Prevention:
If the offending allergens have been identified through allergy testing, the owner should undertake the responsibility to reduce the pet's exposure to those for which it is possible. For example: house dust, animal dander, and indoor mold spores. Minimizing other source of itching such as fleas, foods, malessia in the ears and dirt, unkempt hair coats will help the dog keep allergies at a tolerable threshold.
Medicines Used for Treatment of Disease:
Allergy testing and desensitization with allergy injections, corticosteroids, anti-histamines, antibiotics for skin infections, demodex treatments as needed, ear cleansers and ear treatments for malessia and infections, anti-bacterial and anti-histamine shampoo and cream rinses, shampoos to treat skin yeast. Prescription diets with skin supporting nutrients, and dietary supplements to promote a healthy skin barrier.
Helpful Products:
Antibiotics, anti-histamines, nutritional support such as IVD Skin Support Diet, Hypoallergenic diets, Fatty acid capsules such as Derm Caps and 3V Caps to maintain a healthy skin barrier, shampoo therapy to cleanse scales, kill yeast and bacteria, and flush the hair follicles (Malaseb, Sebolux, SulfOxyDex, Chlorhexiderm ,etc) . Use frequently when dog smells bad even if more than weekly. Anti-histamine shampoos (Relief Shampoo and Cream Rinse) are soothing topically. With long haired dogs, consider clipping hair short to facilitate bathing and so you can monitor the condition of the skin. Check the ears often for problems. Malaseb Skin Wipes for skin fold infections, especially around the lower muzzle, face and in between toes.
