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January 13, 2023

Food Allergies and Intolerances in Dogs

  • Health Issues
  • Signs + Symptoms
  • Allergies
  • Ingredients
  • Protein
Senior dog looking over blanket

An adverse food reaction (AFR) is a catchall phrase that can be used to describe an inappropriate response to an ingredient found in a food, often a protein. In dogs we see food intolerances and food allergies, with food allergies resulting in more severe symptoms. True allergies involve an immune system response where the body attacks the offending agent (food) and sets off a storm of physical events.

Adverse food reactions can show up at any age, and although many cases appear early in life, some may take years to develop. Many dogs with diagnosed food allergies also have concurrent inhalant or contact allergies (e.g. flea bite allergies).


The symptoms of adverse food reactions are similar to those of environmental allergies.

Symptoms of Adverse Food Reactions

  • Itchy skin
  • Chronic or recurrent ear infections
  • Hair loss
  • Excessive scratching
  • Hot spots
  • Re-occurring skin infections
  • Vomiting
  • Diarrhea

Food allergies are different from food intolerances. Intolerances typically manifest as digestive upset which occurs in reaction to a food component that does not agree with the animal (e.g. lactose intolerance) and does not invoke an immune response; allergies induce an inappropriate immune system response to an ingredient in which the body treats it as unsafe foreign material. Food sensitivities can arise from various types of ingredients, whereas food allergies typically occur in response to proteins. If left untreated, a food intolerance in dogs may progress to a food allergy and potentially to the development of irritable bowel disease.


Diagnosing an adverse food reaction can be challenging. Blood and skin-patch testing are available for a number of ingredients found in pet food, however, these tests are for food allergies, not intolerances. Although the testing may show which ingredients do not produce a reaction, allergy testing can provide false positives or an incorrect result.

The “gold standard” to diagnose an adverse food reaction is a food elimination-challenge trial. This trial, in part, consists of feeding a novel protein source, one that the dog has not eaten before, for at least 6-8 weeks.
Michele Dixon
Michele DixonHealth and Nutrition Specialist

Go! Sensitivities Limited Ingredient Duck Recipe is an example of a diet that may be an option for a food elimination trial as it includes all the nutrients that dogs require with as few ingredients as possible. Regardless of the diet used, it must be the only thing the dog eats for the 6-8 weeks. This means no treats; absolutely nothing but the special food and water. When the 6-8 weeks are up, the ingredient that was thought to create a reaction would be re-introduced as a "challenge." If there is then an adverse reaction, an adverse food reaction diagnosis would be confirmed.


Recommended Solution

Limited ingredient recipes for your canine friend

Our Go! Solutions Sensitivities recipes are specially formulated by experts to help dogs suffering from food sensitivities.

For many people, the “challenge” part of the food trial is not completed because once they find a food that works, there is a tendency to stick to that food and no desire to provoke a potential reaction. However, without this challenge, a diagnosis of adverse food reaction cannot be as definitive.

Finding out whether your dog is experiencing an adverse food reaction can be tricky, but taking the time and putting in the effort to find out can certainly help your dog lead a healthier and more comfortable life.


Michele Dixon

Michele Dixon

Health and Nutrition Specialist

Michele studied animal nutrition through Colorado State University and the Companion Animal Sciences Institute. Involved in animals and nutrition for over 25 years, Michele had the pleasure of receiving a High in Trial with her first Borzoi Yascha at an early age.