Food sensitivities vs. food allergies in dogs — what you need to know

food sensitivities and food allergies

Learn the best treatment approaches to food allergies and sensitivities, and how to prevent these issues in your dog.

Does your dog have a “sensitive” stomach? Does she react badly to certain foods? Is she itchy year-round? She could be having a reaction to her food. Many dogs experience food sensitivities but these symptoms don’t necessarily indicate a food allergy. In fact, relatively few dogs are truly allergic to what they eat. So how can you tell the difference and, more importantly, how can you help your dog?


A food allergy is an immune reaction to a particular protein. Experts believe that between 10% and 30% of food reactions are allergic in nature. True food allergies tend to develop over long periods (months to years) in response to foods or treats the dog eats frequently or chronically. They are uncommon in dogs under one year of age. Common proteins, and therefore common allergens, include:

  • Beef
  • Chicken
  • Corn
  • Soy
  • Dairy
  • Egg
  • Wheat

KEEP IN MIND: Around 80% OF CORN and 60% OF SOYgrown in Canada is genetically modified (the numbers are over 90% in the U.S.). Most of these crops go to animal feed. While the ultimate and cumulative effects of GM foods are still unknown, protein alteration is, by definition, a given.

A food allergy may cause either gastrointestinal symptoms(vomiting and/or diarrhea) or skin symptoms (itchiness, rash, hot spots). Skin symptoms of food allergies may include extreme itchiness, and secondary infections with bacteria and yeast are very common. Just to complicate things a little more, allergic skin disease is more commonly associated with inhalant allergies(collectively referred to as “atopy”), fleabite hypersensitivity or other causes.

It’s important to note that atopy causes skin symptoms and is often confused with food allergies.


A food sensitivity or intolerance causes symptoms primarily in the gastrointestinal system. A dog experiencing symptoms related to food may be sensitive or intolerant to one main ingredient, or to one or more of the colourings, preservatives, texturizers, palatability enhancers, or other additives. Food intolerances can occur at any age and involve any ingredient.


There are two approaches to dealing with food allergies and sensitivities:

1) For food allergies, a full “diet trial” determines the allergy-causing ingredient/s. Feed your dog one“novel ingredient” or hypoallergenic food for eight to 12 weeks. Choose a protein that is not included in your dog’s normal food — e.g. venison, rabbit, duck, or kangaroo. Dogs already eating a single-protein food may do fine on different proteins like fish, lamb or turkey, even if they are common in other foods.

Also opt for novel carbohydrate sources (since all carb sources contain some protein), such as sweet potatoes, rice or barley.

A diet trial must include only the test food and water— no exceptions! Just one goof (such as giving a treat or supplement containing beef liver to a beef-allergic dog) could take you back to square one.

Digestive symptoms may resolve quickly, but skin symptoms are far more persistent. If symptoms do clear up, you can then challenge your dog with one ingredient at a time to figure out what was causing the problem.

In addition to high quality commercial foods, many people have had great success using raw meat-based and homemade diets. Many animals that are allergic to a particular protein in cooked food do well with the raw version of the same protein.

KEEP IN MIND: Note that the word “poultry” may include chicken, turkey, duck, quail or other fowl. “Meat” is usually beef, but may legally include pork, lamb and goat. It’s best to CHOOSE A FOOD WITH SPECIFICALLY NAMED SINGLE INGREDIENTS.

2) The treatment for food sensitivity is simple. Changing the brand or flavour of food may resolve the problem. Symptoms will diminish or disappear within days. Of course, this may be easier said than done with very sensitive dogs, since they may react to multiple foods. To maximize success, choose good quality natural foods without artificial additives. Don’t forget that your dog still needs variety to prevent worse problems down the road.

Preventing Problems


Remember, food allergies develop when a dog eats the same thing regularly or for a long time. And dogs that develop an allergy to one food are more likely to eventually react to other foods too.


Make the switch gradually over a week or two, so the bacteria in the colon have time to adjust; too fast a change can cause diarrhea. Stick with high quality natural foods that don’t contain “mystery meat”, synthetic preservatives or other artificial additives. High quality natural foods tend to contain purer ingredients that are less likely to cause an adverse reaction.


DIGESTIVE ENZYMES: Can be given with food to help your dog break down proteins more completely, so they are less likely to trigger an immune response.

PROBIOTICS: Help keep the gut bacteria happy and healthy, and appear to have some anti-inflammatory properties.

OMEGA-3 FATTY ACIDS (MARINE): Are naturally anti-inflammatory, as well as important for skin healing. The intestinal tract is lined with a type of skin cell that can also benefit from Omega-3 supplementation.

With time and persistence, you’ll get to the root of your dog’s food allergy or sensitivity!