Treatments can help pets with allergies

Chances are you have a pet, or know a pet, that itches, chews, licks or gets ear infections.

That’s because the most common cause of these problems is a very common ailment: allergies!

Depending on where you live, somewhere between 10 and 30 percent of pets are affected by allergies.

Flea allergic dermatitis is the most common allergy in dogs and cats,

Atopy (allergic inhalant dermatitis) is the No. 2 allergy in dogs followed by food hypersensitivity, says Dr. Kathy MacLeod, a board-eligible veterinary dermatologist practicing in Lexington, Ky.

However, telling these types apart is not always easy.

Atopy develops in dogs and cats that are genetically predisposed to making antibodies to normal environmental proteins.

Under normal circumstances, antibodies are protective. However, in the case of atopy, the antibodies have a detrimental effect.

In the allergic patient, the antibodies interact with normal environmental proteins, called “antigens,” including the pollen from trees, grass and weeds as well as house dust, dust mites, animal dander and molds. This interaction results in the allergic reaction.

Dogs and cats usually manifest their allergies through the skin, as opposed to respiratory signs seen in allergic humans like sneezing, coughing and asthma.

Allergic signs include foot licking, scratching at their arm pits, belly and legs, face-rubbing, “hot spots,” ear infections and secondary infections (scratch, have open wound, gets infected).

“Bacterial and yeast skin infections are common in allergic dogs and cause a noticeable odor, to put it nicely,” said Dr. Trish Ashley, a board-certified veterinary dermatologist at Veterinary Allergy and Dermatology Services in Springfield, Ore.

These problems appear in pets between 1 and 3 years of age but can start as young as 4 months or as old as 7 years.

“No breed is free of this problem,” warns Ashley, “but some breeds are more frequent visitors to dermatology practices.” Those include boxers, golden and Labrador retrievers, cocker spaniels, shar-pei, shih-tzu, Dalmatian, German shepherd and, as Ashley quips, “any breed with the word ‘terrier’ in it, especially the West Highland white.”

Foods, usually a protein in a pet’s diet, are also common allergy triggers.

Like atopy, food allergies cause skin itching and infections. Animals with food allergies may also exhibit gastrointestinal signs such as increased defecation, MacLeod said. One study showed 60 percent of dogs that were itchy also defecated more than five times per day.

Allergies to fleas can be a pet’s nemesis, with one bite triggering chewing and hair loss at the tail base, which progresses down the hind legs and toward the head in a narrowing pattern like an arrow. Flea allergies have become less common thanks to pet-friendly, people-friendly flea-control products such as Advantage (Bayer) and Frontline (Merial).

Diagnosing allergies is based on reviewing a pet’s symptoms, history and a process of elimination. Ashley tells her clients there is no easy and reliable test for any of these allergies.

Food allergies are diagnosed by feeding a limited-ingredient, novel protein food (duck, fish or venison and potato) or specially formulated prescription diets under the close supervision of your veterinarian.

“If an elimination diet hasn’t been done, that’s where I start. I control what I can control, that being food and fleas,” says Ashley, “and if the pet does not improve, then I know I’m dealing with atopy/environmental allergies.

“Sometimes pets improve partially with a special diet, telling me they are the lucky recipient of food allergies and atopy. My own dog, Zoe, a 9-year-old spayed female beagle-cocker mix (a “beaker”!), is an example of this ‘building block’ phenomenon.”

Although allergies cannot be cured, they can be controlled.

Avoidance is ideal but not often practical.

One way pets are exposed to antigens triggering atopy is direct contact on their skin. A simple measure that can help this is frequent bathing with a hypoallergenic shampoo that removes the offending substances from your “pet dust mop.”

Along with this, veterinarians often will prescribe antihistamines and fatty acid supplements such as Eicosaderm (DermaPet) or DermCaps (DVM).

Once the allergic reaction has begun, most experts agree that short-acting cortisone-type drugs usually are the most effective treatment. There is a newer promising therapy available to veterinarians called cyclosporine, an anti-rejection drug commonly used in people after organ transplant to prevent rejection of the new tissue.

The treatment for allergies with the least risk of side effects is desensitization (also called immunotherapy or “allergy vaccines”). Just like the process used in people, this involves injections of the offending antigens.

The drawbacks to desensitization are that only 60 percent to 70 percent of pets respond to this therapy, and it takes time to see results.

An itchy pet can be a miserable critter, and all that licking and scratching can be disturbing to pet owners as well.

For the good of your pet and the bond, ask your veterinarian for help for your itchy pet.