by Dr. Jane Leon
| |
by Dr. Jane Leon |
The dog is scratching, and
scratching, and scratching. When he is not scratching, he is
rubbing and whining. No one in the house can sleep, and the dog
is miserable. You don't see any fleas, so you assume that the
poor animal has an allergy. After all, in this day and age,
everyone seems to be allergic to something, so the dog must be
allergic. Thinking it has to be his food, you switch brands, but
three weeks later, the dog is still scratching, you're still
awake at night, and the dog is still miserable. So, what went
wrong?
Well, the first mistake was assuming that every scratching, itchy
dog must have an allergy. The second mistake was assuming that
the allergy must be related to the food. While it is true that
allergic skin disease is common in our pets, it is not the cause
of all itchy skin. Many other problems can lead to scratching.
These other skin diseases must be identified and treated first.
Otherwise they interfere with the diagnosis and treatment of
allergies. The process of reaching a definitive diagnosis can be
difficult and frustrating, but is the best method to assure
proper treatment for your pet. Merely assuming any itching is an
allergy and guessing about treatment can lead to months and
months of misery for your pet and you.
It is critical to understand that many, many different types of
problems can cause itching, and look the same on the dog. All
these different diseases can cause hair loss, redness, crusting,
itching, bumps, and odor. So, the diagnosis is not based merely
on looking at the dog, but reached by combining the history of
the disease, the pet's physical examination, and specific
diagnostic tests. Sometimes diagnosis is simple; sometimes it is
complicated and many tests and treatments must be tried. The best
way to understand your pet's skin problems is to work with your
veterinarian to find the cause.
Start by creating a list of all the potential problems that could
contribute to your pet's skin problem. A short list of skin
diseases that cause itching might include fleas, lice, ticks,
mites, bacterial infections, yeast infections, fungal infections,
hormonal problems, reactions to drugs, genetic problems, dry
skin, malnourishment, psychological problems, and of course,
allergies. To make things worse, combinations of skin diseases
can occur, so a pet could have allergies to inhalant substances,
food allergies, bacterial skin infections, and fleas at the same
time. Even if the dog really had a food allergy, merely switching
the diet would not solve this poor animal's problems!
Once you have a list of potential problems, your veterinarian can
help eliminate some causes and potentially diagnose others with
simple tests. For example, low levels of thyroid hormone can be
identified with blood work. Parasites can be seen on the dog or
found by a test called a skin scraping (tiny bits of skin tissue
are examined under the microscope). Fungal infections, such as
ringworm, can be identified with a skin scraping, examination
under special lights, and specific cultures, while bacterial
infections and yeast infections can be seen on the skin scraping
and identified with their own cultures. By performing these
simple tests, your veterinarian may be able to eliminate many
possible causes, reach a diagnosis, and start treatment. Even if
a definitive diagnosis is not reached, many potential causes will
have been removed from the problem list, and treatments can be
started. Often, treatment involves combining therapies to control
more than one problem. So a dog may end up taking thyroid
supplements, medication to control yeast and bacterial
infections, and be treated for fleas at the same time.
After all the other underlying problems are identified and
treated, allergies can be considered. Allergies can be quite
complicated and may by caused by many different substances. Pets
may react to anything they eat, inhale, or contact. So, dogs may
be allergic to inhalants such as molds and pollens. They may be
allergic to substances they touch, such as carpet fibers, plants,
or fertilizers. And, they may be allergic to specific ingredients
in their foods, such as corn, beef, or seafood. In addition, they
can be allergic to more than one inhaled substance or food, or
have a combination of allergies and be allergic to both foods and
inhaled substances at the same time.
A good physical examination can help make the diagnosis of
allergies. For example, dogs with contact allergies show itching
and irritation at the points where their bodies contact the
allergen. So dogs allergic to the carpet would have problems on
their feet, bellies, and sides, while dogs with plant contact
allergies would show irritation on their underline and legs. Dogs
with inhalant allergies could display many signs, but the most
common signs are biting their feet and rubbing their faces. Dogs
with food allergies could have digestive signs, such as diarrhea,
but more commonly have rashes, bumps on the skin, and itching.
Sometimes, diagnosis is difficult, so treatment trials with
medications are tried. If the medication works, the diagnosis is
assumed to be correct. Some inhalant allergy treatment trials use
medications, known as antihistamines, which block histamine
release in the body and help to stop itching. The antihistamine
trials involve giving the dog one type of antihistamine and
watching the dog's response for the next two weeks. If the dog
does well on it, everyone is happy, and the dog can be kept on
the specific antihistamine for long periods of time. If the dog
does not respond, another antihistamine is tried for two weeks.
This process is continued until several different antihistamines
are used.
Allergy testing for inhalant allergies can also be performed.
Either skin testing or blood tests may be used. Each type of test
has advantages and disadvantages. Blood tests are easy, less
expensive, and require no practitioner experience. Skin tests are
expensive and require an experienced diagnostician or a
dermatologist to perform and read, but often correlate better to
treatment success.
Once a dog is diagnosed as having allergies, and the cause of the
allergy is identified, dogs with inhalant allergies can then be
treated with allergy shots. These injections are given
approximately once per week for several months or longer. The
injections can be given at home by the owner. Many dogs
experience significant relief after a series of allergy shots.
Food allergies are more difficult to identify. A dog can be
allergic to any food that he has previously eaten in his life,
including dairy, rice, any grain, and any meat source. Merely
switching brands of dog food does not rule out an allergy. The
best way to test for food allergies is to put a dog on a diet
that contains food he has never been exposed to (very difficult
in most dogs) for about 10 weeks. No other foods or treats may be
given. If his skin clears up, this is a presumptive food allergy.
A definitive diagnosis of food allergy would then involve
repeating the entire experiment by feeding the old food, watching
to see if the problem returns, and retesting the new, hypo-allergenic
diet. If the dog clears up again, he has food allergies. This is
a very difficult, time consuming process because most dogs have
been exposed to many foods and could be allergic to just about
anything. It also takes months to get an answer.
Using commercial hypoallergenic diets may be easier than trying
to create a balanced, home-made, allergen-free recipe. There are
veterinary prescription diets specifically made for pets with
food allergies. These diets either have unusual ingredients, such
as kangaroo meat, or have the nutrient sources so broken down
that the dog's body can't identify them as potential allergens.
If a balanced diet is found that gives the dog relief from
itching, he may be fed this food forever to prevent future
problems.
So, let's get back to our really itchy dog that is keeping you
awake at night. Let's assume that the dog does not have fleas, or
lice, or mites, and has no other identifiable problems. A
presumptive diagnosis of inhalant, allergic skin disease has been
made. You have an appointment for allergy testing next month.
But, meanwhile the dog is still itching and the allergy shots can
take months to work. So what can you do?
Well, there are a few things you can do at home to help these
itchy dogs. Ask your veterinarian about the use of oral
antihistamines, and set up a bathing regime for the dog. Do not
bathe too frequently, as this can lead to dry skin, but bathe the
dog when he is miserably itchy, has a bad odor, or as your
veterinarian recommends. Look for shampoos, rinses, and sprays
that give relief from itching. These products are listed as hypo-allergenic,
soap free, and anti-puritic, and contain ingredients such as
oatmeal, fatty acids, moisturizers, or pramoxine. Some examples
include Relief Shampoo, Relief Crème Rinse, and Relief Spray,
along with. Derma-Pet's Allay Oatmeal Shampoo, and those products
made by Francodex and Tomlyn for dry and sensitive skin. There is
also a new product, called Allermyl Shampoo, made specifically
for pets with inhalant allergies. Anti-puritic shampoos, followed
by a soothing crème rinse, will give most itchy dogs temporary
relief.
Many allergic dogs also benefit from the addition of fatty acids
into the diet. These fatty acids are anti-inflammatory and help
control itching. Studies show that as many as 25-50% of itchy
dogs get relief from fatty acid supplements. Look for those food
supplements high in omega-3 fatty acids. Lipiderm and 3-V Caps
are good brands of the correct type of fatty acid for itchy dogs.
Additional studies show that the combination of oral
antihistamines and fatty acid supplements can be very effective
at controlling itching. Expect it to take up to four to six weeks
for fatty acid supplements to work.
There is no one best treatment for all itchy dogs. Once the cause
is identified, treatment is aimed at eliminating the cause and
controlling the itching. Using proper shampoos, food supplements,
and antihistamines can help many dogs, but nothing will replace
proper veterinary care for your pet. So stock up on supplies, but
bring your pet to the vet. The dog will stop scratching and
you'll both sleep through the night, at last.
Sincerely,
Dr. Jane Leon
Please refer any questions regarding this article to Dr. Jane Leon at drjaneleon@omahavaccine.com or call toll free 1-866-540-2703.
KDTC would like to sincerely thank Dr.
Jane Leon for her kind permission to reprint this article on our
website.
Home Classes Inside KDTC Newsletter Articles Instructors Featured Members Projects Rescue Web Resources Site map Fun Graphics