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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.
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