Treatment of Allergies in Pets

April 15, 2015
AMC's dermatologist, Dr. Mark Macina, examines a patient

AMC’s dermatologist, Dr. Mark Macina, examines a patient

Spring officially arrived nearly three weeks ago, but the onset of allergy season may not arrive too soon this year, given our harsh winter. But once it warms up, pollen, dust mites, fleas, grass, weeds and mold will kick off allergy season in pets.

Clinical Signs of Allergies
Does your dog rub his face along the front of your sofa or scratch incessantly? Has your cat scratched all the fur off her head and made is scabby? Are you constantly putting in ear drops or giving antibiotics to treat skin infections? All these represent clinical signs of allergies in pets.

Control Parasites
One of the top causes of canine and feline allergic skin disease stems from an allergic reaction to flea saliva. A flea bites your dog or cat, setting off an allergic reaction. This disease presents a double-whammy to your pet: discomfort from fleas crawling all over its skin and the discomfort of being itchy. Fortunately, numerous options for control of fleas are available and your choice of product can be tailored to your pet’s exact needs.

Modify the Diet
Food allergies are typically an ongoing problem, not seasonal like pollen, grass or flea saliva allergies. Veterinarians think the allergen in food is the protein source contained in the diet, but it may be other ingredients as well. The standard method for determining if food is the cause of skin disease is a food elimination trial. Elimination diets contain a limited number of ingredients and protein sources not typically found in common pet food and not previously fed to your pet. Novel protein sources include bison, herring or rabbit. Some elimination diets avoid common carbohydrate sources and include potatoes or oats, rather than corn or soy. An elimination diet requires determination on the part of the pet owner, as the skin improves slowly in response to a diet change. Patience is required to tough out a month or more of strict diet control.

Administer Immunotherapy
Immunotherapy, a medical word for allergy shots, involves specialized testing to determine whether it is pollen, dust mites, fleas, grass, weeds or mold revving up your pet’s itch-scratch pathway. Once the cause of the allergy is determined, a custom allergy vaccine can be developed for your pet. You learn to give the injections at home one to two times per week. These injections contain minute amounts of the offending antigen (pollen, dust mites, fleas, grass, weeds or mold) which trains your pet’s immune system to be tolerant of these agents.

Quell the Immune System with Drugs
A variety of drugs can be used to turn off the allergic reaction underlying the itch-scratch cycle in your pet. The most well-known, but not necessarily the most effective in pets, is antihistamines. Steroids can be very effective and rapidly reduce the clinical signs of allergies, but have unpleasant side effects, such as increasing water drinking, urination and appetite, as well as increasing the risk of infection. Another effective drug for allergy management is cyclosporine, although cost is a concern. New to the market, oclacitinib, inhibits the cells initiating the itch-scratch cycle by attacking allergies at the cellular level.

With so many options to manage pet allergies, no pet should have their summer fun spoiled by constant itching and scratching. Watch The AMC’s Dr. Mark Macina talk about managing allergies in pets.


Allergies in Dogs: 4 Treatments to Help Scratch Your Dog’s Itch

August 6, 2012

The summer of 2012 will go down in my personal history book as the summer of allergies. Not for me, but for my canine patients. I have received many frantic calls from my cancer patients’ families concerned that their beloved pet’s cancer has returned. After a check-up with me at The Animal Medical Center, I have reassured them the cancer continues to be in remission, but their allergies are way out of control.

Scratching bad

Today, the preferred term for allergies to things in the environment, like house dust mites pollen, mold, trees and grasses, fleas, and even your unsuspecting household cat, is allergic dermatitis. Allergic dermatitis is also known as atopy, allergic inhalant dermatitis, seasonal allergy, or environmental allergy. Whatever it’s called, the manifestation is red skin, “hot spots,” ear infections, recurrent skin infections and scratching like mad. The development of allergic dermatitis requires two things: a dog with a genetic predisposition to developing allergies and an allergen in the environment to incite the allergic response. Allergic dermatitis is a complicated disease and often requires complicated therapy.

Complicated cause

At least three mechanisms play a role in allergic dermatitis in dogs. First, the environmental allergen causes the release of histamine from a cell known as a mast cell, which sets off an allergic reaction. T-cells have a yin-yang effect on the immune system, both ramping up the immune system and blocking a protective effect against allergies. Finally, normal skin protects the body from invasion by allergens. Dogs suffering from allergic dermatitis likely have impaired function of the skin cells, allowing allergens access and predisposing your dog to yeast and bacterial infections.

The net effect of all this cellular hysteria: an itchy dog.

Complex treatment regimen

Given the complexities described in the pathways leading to allergic dermatitis, you should not be surprised to receive a small pharmacy’s worth of prescriptions when your dog is diagnosed with allergic dermatitis. What follows is a brief description of some of the more common medications used to treat allergic dermatitis.

  1. Although the role of histamine is limited in canine allergic dermatitis, antihistamines, if they decrease itchiness, are very safe and cost effective.
  2. Shampoos play multiple roles in the management of allergic dermatitis. Bathing your dog is soothing to the skin and decreases surface allergens, and medicated shampoos decrease surface bacteria and yeast. Hopefully, new shampoos will be developed to help augment the lost barrier function of the skin.
  3. Antibiotics and anti-yeast medications are critical in controlling secondary infections in the skin of itchy dogs. The function of deregulated T-cells can be modified by the use of immunosuppressive agents, most commonly steroids, and more recently cyclosporine.
  4. Finally, dogs can get allergy shots, a form of immunotherapy where the immune system is gradually desensitized to the offending allergen. For several of my patients, this form of treatment has dramatically improved their quality of life by decreasing their itchiness and skin and ear infections.

What a pet owner can do

If your dog is scratching, as are many of my patients, see your veterinarian. When my itchy dog patients need more specialized skill than I have to manage their allergic dermatitis, I refer them to a dermatology specialist. You can find a board certified dermatologist on the American College of Veterinary Dermatology website.

I hope one or more of the treatments I have described can help make your dog more comfortable in these waning summer months.


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