Scratch, scratch, scratch … Lick, lick, lick

An up-close look at pet allergies

By Michelle Ganon


Does your pet relentlessly
chew a specific area of his or her body? Or scooch around the room, dragging
along the ground awkwardly using front legs only? Does your dog lick his or her
paws fastidiously or attack his or her ears? These behaviors can be the pet
equivalent of a human’s runny nose and frequent “ker-choo!” in signaling the possible presence of allergies. Judging
by the urgency with which animals sometimes scratch, allergies seem to be as
uncomfortable for animals as they can be for people.

Attempts to alleviate the itch can lead
to other problems, such as permanent skin conditions, fur falling out,
secondary infections, and more. “Owners who notice their pets have issues with
their ears or skin should be seen by their veterinarians quickly,” said Brett
Wildermuth, D.V.M., Diplomate A.C.V.D., from the Animal Dermatology Clinic in
San Diego. “Allergies that are diagnosed early tend to be much easier to

Identifying the causes of an animal’s
itching can require some detective work. Veterinarians may examine a pet’s
medical history for clues, ask owners to fill out a questionnaire to identify
when the problems began and if seasonality is an issue, note the distribution
of lesions, examine bumps and crusts on the skin, and possibly administer a
blood-allergy test to look for allergy antibodies.

Dermatology specialists, who tend to
see pets that don’t respond to standard treatments, can employ more sophisticated
tests, such as an intradermal allergy test. For this test, a specialist shaves
a small area to expose skin, injects up to 70 possible allergens, one at a
time, just under the surface, and watches for a dermal reaction.

Generally, allergies are caused by one
or more of four types of irritants: fleas, foods, atopic materials (airborne
substances, such as pollen, mites and mold), or contact with specific matter,
such as wool or plastic.

Of these, an allergy to fleas is the most
common. Pets with this allergy respond not to the bug itself, but to proteins
in the flea’s saliva that are left on the skin after the bite. A single flea
can bite your pet more than 400 times, so even a small population can have a
big impact.

“It’s hard to overestimate the
importance of regular flea control,” said Laura Stokking, D.V.M., Diplomate
A.C.V.D., at the Veterinary Specialist Hospital of San Diego. “They can be a
problem year round, so owners need to be vigilant.”

Fortunately, treatment and prevention
options have improved significantly from the “old days,” when options usually
included flea powders, collars, over-the-counter shampoos and regular
insecticide treatment of the home environment. Those options have been largely
supplanted by the new, more targeted, and sometimes safer products available

Topical treatments, available through
veterinarians, can effectively stop and prevent long-term infestations by
killing fleas at all stages of their life cycle and
preventing new problems from starting. An oral regimen also can be used to quickly control a
particularly heavy infestation.

An allergy to ingredients found in food
can emerge, seemingly out of nowhere, even with foods pets have happily eaten
for years. Typical culprits include beef, dairy products, chicken, wheat,
chicken eggs, corn and soy, but anything an animal ingests can be suspect.

“Pets can be allergic to many different
types of food. Some people think lamb is hypo-allergenic because it used to be
a common novel protein used for food tests,” said Dr. Stokking. “Now that pets
are eating more lamb, we’ve seen more allergies to it.”

When a food allergy is suspected,
veterinarians typically suggest a food trial. Animals are fed foods they have
not eaten before, one protein and one carbohydrate, such as a mix of kangaroo
and oats or duck and peas, for a prescribed period of time. If symptoms
decrease or disappear during the trial period, then recur when the original
diet is reintroduced, food allergies are diagnosed. Finding the specific
allergen requires reverting to the trial diet and reintroducing one new
ingredient a week. Food may need to be hand- prepared during this time.

Dr. Wildermuth recalls a case where a
pet helped with its own diagnosis. “A dog undergoing a food trial helped
himself to some potato chips,” he said. “The owner noticed the dog began to
itch again, so this pet is now on a long-term diet free of potato.”

2008_jul_sdpets_18paw Environmental irritants that can cause
allergies include dust mites, molds, and dander from other cats, dogs, or
humans. Ear infections, licking paws and chewing feet, and red, inflamed,
infected “hot spots” can signal an atopic allergy.

“Time of onset and seasonal outbreaks
can help us identify specific problems,” said Dr. Stokking. “In San Diego, our
‘seasons’ can be tied to the presence or absence of marine layers and Santa
Anas. Plants can pollinate multiple times here, so referring to spring or fall
is less meaningful here than it is elsewhere in the country.”

Basic treatments for environmental
allergies might include using antihistamines, bathing with special shampoos,
adding fatty acids in special proportions to food as directed by a
veterinarian, and sometimes using cortisone or steroids. Specially developed
allergy shots, given by owners, two to three times per month can be used to
desensitize a pet to an allergen.

Contact allergies are the least common
form of allergies in pets. Once identified, they can be fairly easy to manage,
as long as it is possible to eliminate or minimize contact with the irritant. A
pet with an allergy to plastic will feel better if plastic food dishes are
replaced with metal ones.

Though allergies can not be cured
completely, the symptoms can be treated, with the result that your pet may
become more inclined to lick your hand or sit quietly at your feet than to
frantically attempt to scratch a ceaseless itch.


— Michelle Ganon is a San Diego-based writer and proud
parent of two dogs.


Courtesy of sdPets — Lifestyles of the San Diego Pet, from
the Union-Tribune, with permission.


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