Food Allergies in Dogs

Jeanne van der Veen, MS, PAS, Equine & Specialty Nutritionist

What is a food allergy?
A food allergy is the result of the immune system mistakenly perceiving a harmless substance, typically a food protein, as something dangerous to the body. The immune system then fights this protein, known as an allergen, by over-producing antibodies to attack it. The next time the animal consumes this protein, the immune system is ready, and it reacts by releasing histamine and other chemicals which trigger the symptoms of an allergic reaction. The degree to which the immune system reacts during exposure to the allergen can vary from very subtle signs to life-threatening situations. It may also take years of repeated exposure to a specific food allergen before the immune system responds with an allergic reaction.

Signs of a food allergy:
Symptoms of a food allergy in dogs are similar to some medical disorders as well as other allergies (such as environmental allergies). Thus it is important to work with your veterinarian to rule out other medical conditions when you suspect a food allergy. Symptoms of a food allergy in dogs may include excessive scratching or licking due to itchy skin (especially around the face, muzzle, paws, ears, armpits and hind area), hot spots, skin rash, hives, chronic ear infections or inflammation and sometimes nausea and vomiting. Food allergies should not be confused with food intolerances. An intolerance is a digestive problem in which the digestive system does not digest a specific ingredient properly. Symptoms of food intolerance include gas, bloating, nausea, vomiting, or diarrhea.

Suspect ingredients in dog food:
Some of the more common ingredients that may cause an allergic reaction in dogs include, but are not limited to, beef, chicken, dairy products, eggs, corn, wheat and soybeans. Note that these ingredients are typically the most common in dog foods, yet only a small percentage of dogs actually develop a true food allergy. The list of ingredients in descending order by pre- cooked weight can be found on any dog food product packaging, most often on the back or side panel of the bag.

Diagnosis and treatment of allergies:
An accurate diagnosis of a specific food allergen can be very difficult and time consuming as it involves performing various food trials (8 -12 weeks long) starting with a completely unique diet containing only ingredients that your dog’s immune system has never been exposed to in the past. Then individual ingredients are added back to the diet in successive trials to determine which ones cause a reaction.

Treatment of a food allergy is to simply avoid products that contain the offending ingredients. Since new allergies can develop over time, the trial process would have to be repeated as new allergies emerge.

Another option, while not conclusive, would be switching to a feed product that contains new or different meat and grain protein sources from the one that is believed to be causing the allergy. Since an allergy can develop to any diet for any ingredient or combination of ingredients, it may be necessary to try several different types of products before finding the one that works for your dog.

The Blue Seal Life Stages brand offers two products that may be beneficial for dogs showing signs of food allergies to the most common meat and grain sources. Blue Seal Life Stages Lamb and Rice Dog Food and Blue Seal Life Stages Pork and Barley Dog Food contain single-source meat proteins (lamb meal or pork meal, respectively) and a combination of Rice, Barley, and Oats as the grain sources. These alternative protein sources may be suitable for dogs with food allergies to the more common meat and grain ingredients.