Canine Atopic Dermatitis

Canine Atopic Dermatitis
For so many people fall sends the allergy season into full swing! But did you know
that our dogs can suffer from allergies too? Seasonal allergies in dogs are called Canine Atopic
Dermatitis or Atopy for short. This common allergic skin disease is second only to flea allergy dermatitis, and affects about 10 percent of dogs. Atopy first occurs between the ages of one and three.
The condition is hereditary so all pets showing clinical signs should not be bred. Susceptible breeds
include Golden Retrievers, Labrador Retrievers, Lhasa Apsos, Wire Fox Terriers, West Highland
White Terriers, Boxers, and Bulldogs. Even mixed breeds may suffer from atopy.
Clinical signs:
Clinical signs generally occur during late summer
into fall when so many of the pollens are at their
highest counts. Some unlucky dogs have indoor
allergies, usually to house dust, grain mites, or
molds, and may show symptoms year-round.
Dogs with atopy are EXTERMELY itchy. Owners often complain that their pet is miserable and
does not want to eat, sleep or play because the
itching is so intense. Hair loss occurs due to
scratching and rubbing and is seen on the face,
feet, armpits and belly. The pet’s skin is reddened, inflamed and irritated. Secondary skin infections are commonly seen as the result of
chewing and scratching. Because the symptoms
of atopy are similar to other allergies, such as
topical and food allergies, your veterinarian may need to ask a series of questions to identify possible causes as well as test for other causes of itching such as fleas and mites.
Why do allergens cause itching?
Allergens are inhaled, ingested and absorbed through your pet’s skin
and cause the immune system to produce a type of antibody called
IgE. This protein then attaches itself to “tissue mast cells” that are located in large numbers in the skin. This attachment causes mast
cells to release large amounts of irritating chemicals such as histamine, which cause inflammation and puritis (itchiness) in the skin.
Intra-dermal testing
A definitive diagnosis of atopy can be made in on of two ways. First is
through allergy testing, both intra-dermal and blood testing. These tests actually use the dog’s skin or blood and expose it to a number of allergens. If
a pet responds with a reaction then that allergen is a problem. Intra-dermal
testing is done through a Veterinary Dermatologist as the tests are very
sensitive and requires extra equipement. Blood testing can be run through
your local veterinarian. Both are great ways to learn the exact allergens your pet reacts to, however
the tests are expensive ranging from $300 to $500. The second method is eliminating individual allergens from the animal's environment until the culprit(s) is isolated. This is obviously near impossible as it is hard to keep pets off grass and away from pollens in the air. Most veterinarians diagnosis
atopy by eliminating other causes of skin disease such
as fleas, mites, food allergies and so forth. A series of
Avoidance Suggestions
questions, physical exam and good history are often
House dust
Keep pets out of room several hours
enough to clue vets in that atopy is the problem.
when vacuuming
Unfortunately, no one treatment works for all dogs and
even several treatments combined may not be 100% affective for any one pet. Most veterinarians agree that
patients require several therapies at one time to help with
atopy. The main goal is to keep the patient’s discomfort
to a minimum. Remember allergies are never cured and
most dogs will need treatment for life through their allergy season. Treatment requires owners to be very diligent and proactive, but the results are often well worth
the hard work.
House dust
Change furnace filters regularly
Use a plastic cover over pet's bed
Wash bedding in very hot water
Avoid letting pets sleep on stuffed furniture
Avoid stuffed toys
Keep pets in uncarpeted rooms
Run air conditioner during hot weather
Change furnace filters regularly
Keep pets out of basements
Keep pets indoors when the lawn is
Avoid dusty pet foods
Clean and disinfect humidifiers
Use dehumidifiers
Avoid large numbers of houseplants
Avoidance: This can be an important part of managing
atopy. As stated above it is impossible to eliminate all
Keep dogs out of fields
Keep grass cut short
allergens but reducing the allergen burden is very benefiRinse dog's feet off after dog has been
cial. The fewer allergens absorbed through the skin, the
less symptoms your pet will experience. Simple steps
Keep pets indoors during periods of high
pollen counts
such as washing off the dog's feet after he or she comes
in from the outside will remove any allergens and help
decrease the itching. Please see the chart for more great ways to avoid specific allergens.
Topical therapy: Topical therapy consists of shampoos, rinses and topical anti-itch solutions. Topical therapy offers immediate, but short-term relief. Veterinary Dermatologists recommend bathing
atopic dogs at least once a week with a prescription hypoallergenic shampoo containing oatmeal,
fatty acids and allergen reducing agents. These shampoos help to rehydrate the skin, rinse off allergens, and increase the skin barrier so that allergens cannot be absorbed. Topical solutions containing hydrocortisone may be applied in-between bathing for localized itch relief.
These products in combination with other therapies
can decrease or eliminate the need for stronger
medications such as steroids..
Omega 3 Fatty Acids: Fatty acids have been recommended for years to improve coat quality and shine however research has shown that the omega-3
fatty acids are also very beneficial in the management of allergies in dogs and
cats. These work in the skin to help reduce the inflammation caused by histamine and other chemicals released in response to allergens. Most pets need
to be on the omega-3 fatty acids daily for several weeks in order to notice significant improvement. These supplements are safe and easy to use products
and can greatly decrease your dog’s clinical signs.
Antihistamines: Antihistamines are widely used in both the human and animal medical fields for allergies. They work by stopping the histamine release from mast cells when allergens bind to their
surface. Antihistamines are effective in controlling allergies in up to 30% of dogs. As with any medication, each pet responds differently and your dog may need to try a variety of antihistamines before
finding one that is most affective for him or her. Remember that these meds may not totally stop the
itch but they can help make the pet more comfortable. You should always consult your veterinarian
before using antihistamines.
Steroids: These drugs are very affective at relieving your dog’s symptoms
however long term use can cause some serious health issues. Steroids work
by decreasing the body’s allergic response thus relieving the inflammation and
itchiness your pet experiences. When your dog's itching becomes unbearable
for both of you, then short term injectable or oral steroids may be given to get
him or her over the immediate crisis and give other therapies time to start working. Side effects associated with the use of steroids include increased thirst,
urination, and appetite as well as hyperactivity, and panting. Long term use of
steroids can lead Diabetes Mellitus, and Cushing disease. It is very important
to try other therapies along with steroids. Even if your pet still needs an occasion dose of mediation, the use of bathing, fatty acids and antihistamines can greatly decrease the
required dose therefore lowering the chance of unwanted side affects.
Cyclosporine: This medication is used to treat itchy skin caused by atopic dermatitis
in dogs and can be very affective. It works by suppressing the immune system so it
does not respond as strongly to the allergens thus decreasing clinical signs. Cyclosporine can be expensive at first but as it begins to work the dosage decreases and
the cost becomes more manageable. Because this medication decreases the immune
system, it is recommended that patients on long term usage have regular blood work to
ensure proper white blood cell counts.
Allergy Shots (hyposensitization): An animal must undergo intra-dermal skin or blood testing prior
to hyposensitization. After the exact antigens are identified, a solution is
prepared for your pet’s specific allergens. The solution is injected every
week to every month and over time the animal becomes de-sensitized to
the offending allergens. This mean that his or her body learns to deal with
the allergens in less extreme ways. Success can vary greatly with this
treatment plan and requires a dedicated owner and veterinarian. Cost
can also be a factor as the allergy shots are expensive.
Remember that Atopy is a life long condition and one that cannot be
cured. Fortunately with a combination of the above therapies and
help from your veterinarian, your dog can find a way stop scratching
that seasonal itch.