Food Allergies in Dogs

One of the most common allergies affecting dogs, a food allergy causes their immune system to overreact and produce antibodies against some part of their food -- usually a complex carbohydrate or a protein. Because the production of antibodies is needed in order for an allergy to develop, food allergies usually occur after dogs’ prolonged exposure to one brand, form or type of food.

Signs of a food allergy are typically itchy ears, paws or skin and/or such digestive disturbances as diarrhea or vomiting. Other signs may include hyperactivity, lack of energy, weight loss and, in some cases, aggressive behavior. While any food ingredient, substance and/or additive can produce an allergy, proteins, particularly those from beef, chicken, chicken eggs, dairy, soy, or wheat gluten are the most common culprits. Therefore, each time dogs eat food containing any of these known offenders, the antibodies in their systems react with the antigens, causing symptoms to occur.

Should YOUR dog be manifesting any of the above symptoms, the most accurate way to diagnose his particular food allergy is called an elimination trial. This involves feeding him a hypoallergenic diet for eight to 12 weeks as a food trial. In order for it to be a true elimination trial, this special diet must NOT contain any of the ingredients eaten by your dog in the past. During this trial period, do NOT give him any other foods, treats or supplements, including flavored vitamins and certain parasite preventatives.If his allergy symptoms resolve while on the food trial, the next step is a “food challenge,” in which you re-introduce his former food. If, however, your dog’s symptoms resolve during the food trial, only to return within one week of the “food challenge,” he definitively has a food allergy. The solution: consulting your vet about feeding your dog one of three types of hypoallergenic diets that are typically available at a veterinary clinic. They are:

A veterinary hydrolyzed protein diet, in which the protein molecules are broken down to a size too small to be recognized by your dog’s immune system (e.g., Hill’s Prescription Diet z/d®, Royal Canin Hypoallergenic Hydrolyzed Protein® or Anallergenic™, and Purina ProPlan Veterinary Diets HA Hydrolyzed®).

A veterinary novel protein diet that doesn’t contain any products present in your dog’s previous foods (e.g., Hill’s Prescription Diet d/d®, Royal Canin Selected Protein PD® or Selected Protein RC®, Rayne Nutrition Kangaroo-MAINT™, Rabbit-MAINT™, or Crocodilia-MAINT™).

A home-prepared novel protein diet that doesn’t contain any ingredients found in your dog’s former diet. This diet must be prepared for you by a veterinary nutritionist and requires the addition of a balancing supplement such as Hilary’s Blend for Dogs™ or Balance IT®.

While some commercial dog foods claim that they’re either a “limited-ingredient” dog food or that they don’t contain the ingredient(s) your dog’s allergic to, please note that, unlike veterinary diets, retail pet foods aren’t manufactured with the extreme health and safety protocols required to prevent cross-contamination.

With no “cure” for food allergies, the only solution available is avoidance. While some dogs may require some form of medication during a severe allergic episode, the majority of them do exceptionally well being fed a hypoallergenic diet.