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Introduction
The most common medical complaint we see in dogs is skin or ear
related. Unlike humans who react to allergens with nasal symptoms,
dogs react with skin problems. These problems may range from poor
coat texture or length, to itching and chewing, to hot spots and
self mutilation. Allergies may also play a part in chronic ear infections.
To make matters more difficult to diagnose and treat, thyroid disease
may add to the problem as well.
In order to overcome these frustrating symptoms your approach needs
to be thorough and systematic. Shortcuts usually will not produce
results and only add to owner frustration. This article will cover
diagnosing and treating; inhalant, food, and flea allergies. I will
also briefly discuss thyroid disease and immune mediated disorders.
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Remember, your best source of information is your vet. Many vets are now
recognizing the need for holistic allergy treatment instead of the tried
and true (and possibly ineffective or dangerous) standby of corticosteroids.
If your vet is not helpful, keep looking until you find someone you are
comfortable with. You need to remember though, that the success or failure
of treatment will rest mainly on you. There is no magic pill to deal with
these problems. Unfortunately, there is also no "cure; only systematic
treatment options. Much of the information below is taken from "Guide
to Skin and Haircoat Problems in the Dog" by Lowell Ackerman, DMV.
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Inhalant Allergies
Substances which can cause an allergic reaction in dogs are much
the same as those which cause reactions in people including pollens,
dust mites and molds. A clue to diagnosing these allergies is to
look at the timing of the reaction. Does it happen year round? This
may be mold or dust. If the reaction is seasonal, pollens may be
the culprit.
Symptoms of inhalant allergies include: SCRATCHING, BITING, CHEWING
AT FEET AND CONSTANT LICKING. The itching may be most severe on
feet, flanks, groin and armpits. Dogs may rub their face on the
carpet. Ear flaps may become red and hot. Chronic ear infections
may follow. Skin becomes thickened, greasy and has a strong odor.
Hot spots may develop due to irritation from constant chewing or
scratching, which is then followed by infection. Allergies have
also been implicated as a possible cause of Acral Lick Granulomas,
a frustrating, treatment resistant condition whereby the dog creates
a sore on his skin from constant licking.
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DIAGNOSIS
If a dog has the above symptoms and responds well to the treatment measures
outlined below, no further diagnostic tests may be needed. If the problem
is severe and does not respond to simple measures, allergy skin testing
can be done. A portion of the skin is shaved and a variety of substances
are injected into the skin to see if they provoke a reaction. If so, an
individual series of injections are formulated to give the dog over a
period of time (there are blood tests designed to identify allergens without
the skin testing, however their efficacy had not been proven. They should
be reserved for cases where skin testing is not possible).
TREATMENT OPTIONS
Symptomatic Therapy Treating the dogs symptoms may include; cool baths
with or without colloidal
oatmeal, Epsom salts, or medicated shampoos. This can be done frequently
but provides only temporary relief. Caution should be used with sprays
and ointments because many contain potentially harmful substances. According
to Dr. Ackerman, Dermacool is a safe spray containing witch hazel. Cortispray
is a low dose, nonsystemic cortisone spray which can be safely used for
short periods of time.
Immunotherapy
Allergy shots are very safe and many people have great success with them,
however, they are very slow to work. It may be six to twelve months before
improvement is seen. I spoke with Dr. Christine Johnson, a veterinarian
with the dermatology department of the University of Pennsylvania, about
intradermal skin testing for inhalant allergies. She reports the average
success rate is 70-75%. This rate is for dogs showing any improvement
at all. At U of P. the cost for the procedure is $69.00 for the exam,
$122.00 for the sedation and testing, and $85.00 for the first 5 months
worth of vaccine. After that vaccines are purchased in 7 month supply
for $65.00. Substances that are tested include cats(!), feathers, wool,
molds, dust, trees, insects, plants and pollens. Before testing, your
pet must be free from all steroids, oral or injected (including those
found in ear and eye medicines) for a specified period of time in order
for the test to be valid. In all about 60 different substances are tested
for.
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Corticosteroids
These compounds reduce itching by reducing inflammation. Unfortunately,
they also affect every organ in the body. According to Dr. Ackerman,
steroids should be considered only when the allergy season is short,
the amount of drug required is small or as a last resort to relieve
a dog in extreme discomfort. Side effects can include increased thirst
and appetite, increased need to urinate and behavioral changes. Long
term use can result in diabetes, decreased resistance to infection
and increased susceptibility to seizures. You can recognize steroids
by the suffix "-one", such as cortisone, dexamethasone,
prednisone..etc.. In short, alternatives to steroid therapy should
always be considered. Antihistamines Antihistamines can be used with
relative safety in dogs. About one third of owners report success
with them. The major drawback, as with people, is sedation. Dr. Ackerman
recommends that a minimum of three different types of antihistamines
be tried before owners give up on this therapy. According to Dr. Johnson,
the most common problem with this type of treatment is that owners
give the drugs at doses that are too low. Check with your vet on correct
dosing. Examples of antihistamines commonly used for dogs include:
Tavist, Benadryl, Chlortrimeton, Atarax and Seldane. Personally, I
have seen the best results with Atarax.
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Omega-3 and Omega-6 Fatty Acids
These fatty acids are natural anti-inflammatory agents. They reportedly
are helpful in 20% of allergic dogs. My own experience puts this figure
a little higher. They are certainly worth a try because they are not harmful
and have virtually no side effects. Omega-3 fatty acids are found in fish
oils (especially krill and cod) and omega-6 fatty acids are derived from
plants containing gamma-linolenic acid (GLA), such as oil from the evening
primrose. These supplements are different from those sold to produce a glossy
coat. They tend to reduce inflammation that may lead to skin sores but are
not as effective in reducing itching. Products that contain both omega-3
and omega-6 fatty acids include: Omega Pet, Derm Caps, and EFA-Z Plus.
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Environmental Control
If you know which substances your dog is allergic to avoidance is
the best method of control. Even if you are desensitizing the dog
with allergy shots, it is best to avoid the allergen altogether. Molds
can be reduced by using a dehumidifier or placing activated charcoal
on top of the exposed dirt in your house plants. Dusts and pollens
are best controlled by using an aircleaner with a HEPA filter. Air
conditioning can also reduce circulating amounts of airborne allergens
because windows are then kept closed.
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Prevention
While there is nothing you can do to prevent a rescue dog from developing
allergies, breeders should be aware that allergic dogs SHOULD NOT BE BRED!!!
Dr. Johnson confirmed that there is clinical proof that allergies are inherited!
Food and Flea Bite Allergies
The previous section of this article dealt with atopy or inhalant allergies.
This article will deal with food allergies or to be more precise, food sensitivities.
Much of the information presented here is drawn from "Hair and Skincoat
Problems in the Dog" by Lowell Ackerman D.V.M. and an interview with
Dr. Scott Krick of the VCA Sinking Spring Veterinary Hospital. Food allergies
account for only about 10% of allergy problems in dogs, however they are
easily treated so it makes sense to test for them if you suspect they may
be the culprit of your dog's skin problems.
Like inhalant allergies, food sensitivities primarily manifest themselves
with itchy skin. Other symptoms include anal itching, shaking of the head,
ear inflammations, licking front paws, rubbing faces on carpeting and rarely
vomiting, diarrhea, flatulence, sneezing, asthma like symptoms, behavioral
changes or seizures. Many people don't suspect food allergies as the cause
of their dog's itching because their pet has been fed the same food all
its life and has just recently started having symptoms. However, animals
can develop allergies to a substance over time, so this fact does not rule
out food allergies. Another common misconception is that dogs are only sensitive
to poor quality food. If the dog is allergic to an ingredient it doesn't
matter whether it is in premium food or the most inexpensive brand on the
market. One advantage to premium foods is that some avoid common fillers
that are often implicated in allergic reactions.
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DIAGNOSIS:
Dogs are not allergic to a dog food per se, rather they react to
one or more of the ingredients in the food. Some of the most common
culprits are beef, pork, chicken, milk, whey, eggs, fish, corn,
soy, wheat and preservatives.Many animals are now developing allergies
to lamb as well. This was once thought to be very hypo-allergenic,
but the more it is used, the more sensitivities are springing up.
The first step in diagnosing a food allergy is to eliminate all
possible allergens and feed ONLY a homemade diet with ingredients
the dog has never eaten before. The diet should be a protein and
a starch. Good examples are one part lamb, rabbit or venison mixed
with two parts rice or potatoes. NOTHING else can be fed during
this time; no biscuits, chewable heartworm pills, chew toys or any
table scraps!! You must also keep the dog away from feces if he
or she is prone to eating stool.
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This diet should only to be fed for a short period, while testing for
allergies. It is not nutritionally complete enough for long term use.
Check with your veterinarian before beginning the test. If the symptoms
improve during the trial diet, go back to the original food for several
days. If symptoms reoccur you know that something in the food is causing
thereaction. The next step is to return to the trial diet and add one
new ingredient a week (i.e. add beef for one week and if no symptoms occur
add corn the next week for one week).
Once you have discovered the allergen you can look for a commercial food
which does not contain that ingredient. According to Dr. Ackerman, approximately
80% of dogs with food allergies can be maintained on a commercial hypo-allergenic
diet. Some of the common hypoallergenic diets include "Nature's Recipe",
"Sensible Choice" and "Natural Life". "Nature's
Recipe" makes a lamb and rice food, a venison and rice diet and a
vegetarian diet, none contain chemical preservatives. "Natural Life"
also makes a preservative free, lamb and rice food called Lamaderm. "Sensible
Choice" is a third brand that is considered hypoallergenic because
it contains neither wheat or corn and comes in a lamb and rice formulation.
Note: just because a food is labeled "Lamb and Rice" do not
assume it is hypoallergenic. Many contain wheat, corn, soy, beef or preservatives.
This process of elimination is trying and time consuming. You should be
aware that it may take up to 10 weeks to see an improvement. However,
it is the best method available to test for food allergies. You may wish
to try switching your dog to one of the foods listed above for a month
as a trial. If the dog shows improvement you know you are dealing with
a food sensitivity, you just won't know which ingredient to avoid. If
there is no improvement, you will need to begin the elimination testing.
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Flea Allergies
This type of reaction, again usually severe itching, is not to the flea
itself but rather to proteins in its saliva. Dr. Ackerman writes that
dogs most prone to this problem, interestingly enough, are not dogs who
are constantly flea ridden, but those who are exposed only occasionally!
A single bite can cause a reaction for five to seven days, so you don't
need a lot of fleas to have a miserable dog.
To test for flea allergies, a skin test is performed which must be read
in fifteen minutes and again in forty eight hours. Unfortunately injections
to desensitize are not very effective because it is hard to collect enough
flea saliva to make a serum! For dogs with this problem a strict flea
control regime must be maintained.We would caution you, however, against
using strong chemical preparations onyour dog. Often times the flea Control
program produces more harmful effects than the fleas, including seizures
and skin problems, so please use caution.
Author: Cheryl Minnier, cminnier@epix.net
Copyright 1996 by the author.
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