Do your pets have trouble with itchy skin? Ever noticed your dog chewing at his feet? How about infected ears or inflamed skin, or even diarrhea? These can all be manifestations of allergies in dogs and cats. Allergies in pets are a common problem, and there are a variety of approaches to management. The very first tool you need to fix your pet’s allergies is a good understanding of the problem…

Food or Environment?

There are two main categories of allergies. An animal may be allergic to food, or to environmental factors such as pollen, dust mites, or mold. In the northeast, among dogs with clinical signs of allergies, about 85% have environmental allergies and only 15% have food allergies. Food allergies are much more common in cats; about 40-50% of cats with clinical signs of allergy have a food allergy.

Diagnosing & Treating Food Allergies

While blood tests for allergies exist, blood tests for food allergies are generally not considered accurate. Instead, we demonstrate that a specific ingredient is a problem by excluding it from the diet and looking for an improvement in allergy symptoms. If the problematic food ingredients are then reintroduced, symptoms will return.

Food allergies are reactions to specific protein ingredients in the food: chicken, beef, lamb, fish, egg, whey, rice, soy, wheat, corn, barley, etc. No need to worry about the vitamin and mineral supplements (with names like “calcium iodate” or “niacin”) that also appear on the ingredient list; they are not at fault.

Here are the steps to follow for a successful food trial with results that can be trusted:

  1. Select a new diet that does not include ANY of the same major ingredients as what you are currently feeding, or have fed in the past. This requires you to read the whole ingredient list on the back of the bags, not just the description of the diet on the front of the bag (a diet called “Lamb and Rice Sensitive Skin” surely includes many more ingredients than just lamb and rice). You may be able to find a kibble that works, or you may have an easier time preparing a home- cooked limited ingredient diet. Diet selection isn’t easy! If you’re uncertain of how to proceed, don’t guess – talk to your veterinarian. In some cases, hydrolyzed or prescription limited-ingredient diets are recommended.
  2. Eliminate any other foods you are currently feeding, as these may also contain the allergen at fault. This means NO TREATS, NO TABLE FOOD, no rawhides or marrow bones, and no flavored medications (such as Heartgard or Rimadyl). Following the same rules for choosing a new diet, you can find an appropriate treat to offer. Several of the limited-ingredient diets aimed at allergy management also make a treat to “match” the diet. Freeze-dried single-ingredient treats (for example, duck jerky) may also be an option. Your veterinarian can help you find safe alternatives to flavored medications for use during the food trial.
  3. Continue this new limited-ingredient diet for 8 weeks, and watch for an improvement. If you do not see an improvement and are certain no foods outside the planned diet were eaten, the problem is not a food allergy.
  4. Continue the limited-ingredient diet, or try adding in other ingredients one at a time and watch for a reaction. You can continue the limited-ingredient diet forever if it is practical to do. If you are using a home-cooked diet, though, you will need to make sure it is nutritionally complete via a free consult at BalanceIt.com.

Diagnosing & Treating Environmental Allergies

Antigen-specific allergy testing and treatment is an option for management of environmental allergies, but environmental allergies can often be addressed without determining the exact allergen(s) at fault.

  1. Remove the allergen, if possible. Check for fleas, and if found, get rid of them for good. Giving your pet a bath regularly (perhaps weekly) during allergy season will physically remove pollen from their fur. Any shampoo will clean away allergens, but your pet may benefit even more from a medicated shampoo that also controls for overgrowth of yeast or bacteria which would perpetuate inflammation of the skin.
  2. Address any infection of the skin that has developed as a result of allergies. Secondary infection of the skin or ears is treated with an antibiotic (oral or topical). In some cases, a prescription ear cleaner or medicated shampoo will be recommended to help heal the skin barrier & prevent recurrent infection.
  3. A daily antihistamine (such as Benadryl or Zyrtec, & generics thereof) may be recommended. Antihistamines work best when they are given daily as a preventative, rather than as a response to an allergy flare-up. Animal doses may be higher than human doses. NEVER give an antihistamine that also contains a decongestant or anti-inflammatory ingredient.
  4. Consider an immune-modulating medication. Medications such as Apoquel (oral) and Cytopoint (injectable) are targeted to control allergic itch while leaving other aspects of immune function unaffected. A steroid may be prescribed for short-term control of itch, but prolonged use of oral steroids must be weighed against numerous adverse effects. Other immune-modulating medications such as Atopica may be considered in severe cases.
  5. Consider a consultation with a veterinary dermatologist for allergy testing and immunotherapy (hyposensitization therapy, “allergy shots”). This method of treatment reduces reliance on other medications long-term. This is the most specific tool available for management of allergies in pets. The immune system can potentially be re-trained to ignore environmental allergens, while leaving its disease-fighting function completely intact. Allergy testing and allergy shots are useful in management of environmental allergies, not food allergies. The “gold standard” of testing for environmental allergies is skin testing, wherein a tiny amount of each allergen is given as an injection into the skin, & shortly thereafter the skin is assessed for the development of an inflammatory response in that location. Anything an animal’s immune system reacts to will be incorporated as an antigen in their allergy shots. Typically, an owner will administer allergy shots at home, as therapy continues for months/years until the immune system is desensitized to the problematic allergens.

Allergies in pets are a complex problem, and regardless of the cause, it can take some persistence to find the best solution. This article is meant to set you off on the right path, and your veterinarian is ready to guide you along the way.

Common diet formulations recommended for food trials include:

  • Purina Pro Plan Sensitive Skin & Stomach
  • Hills Science Diet Sensitive Stomach & Skin
  • Royal Canin Selected Protein series
  • Purina HA, Hills z/d, Royal Canin HP (hydrolyzed)
  • This is not a complete list; additional prescription and non-prescription options exist.
  • Consult your veterinarian to determine the most appropriate choice for your pet.

Our closest veterinary dermatologists:

Unleashed Veterinary Dermatology
Dr Elizabeth Falk & Dr Elizabeth Layne
unleashedvetderm.com
47 Nichols Ave, Stratford CT 06614
Phone: (203) 350-3920
Email: info@unleashedvetderm.com

Tufts Cummings School of Veterinary Medicine
Dermatology & Allergy service
55 Willard Street, North Grafton MA 01536
Phone: 508 839 5395