For answers, I turned to Dr. Jean Dodds. Many of you know Dr. Dodds as founder of Garden Grove, California-based Hemopet animal blood bank and Hemolife testing lab and creator of NutriScan, the first saliva-based food intolerance test for dogs, cats and horses. In the following Q&A, Dr. Dodds will unravel the mystery surrounding canine food intolerances and gives tips on decreasing and preventing foods sensitivities in dogs.
What are “food sensitivities” in dogs?
JD: Food sensitivities, also called food intolerances, are an immune system response to ingredients the body views as harmful. When a dog ingests a problematic ingredient, called a food antigen, the immune system produces the antibodies IgA and IgM to attack and destroy the “invader”. Since every dog is an individual, foods that trigger sensitivities in one dog will not necessarily do so for another. Food sensitivities are chronic reactions that typically build up after repeated exposure to the offending food antigen(s) and usually take months, or even years, before outward signs appear.
What are the most common clinical signs of food sensitivities in dogs?
JD: The hallmark of a food sensitivity is itching, or pruritus, in medical terms. Food sensitivities also typically manifest as gastrointestinal and skin issues. Gastrointestinal signs often mimic Irritable Bowel Syndrome (IBS), such as chronic diarrhea or loose stool, gas and stomach rumbling. Skin problems include unexplained itchiness and infections, especially of the ears and feet, and are often accompanied by yeast. If the offending food is not eliminated, chronic inflammation resulting from the sensitivity may lead to more serious illnesses, such as autoimmune diseases or even cancers.
What is the difference between food sensitivities/intolerances and food allergies?
JD: Food allergies involve a different type of immunologic response. When the body is exposed to a food allergen, it produces the antibody IgE to attack the offending ingredient. Reactions to a true food allergen typically occur immediately or shortly after the ingredient is ingested and symptoms are often severe, such as hives, a swollen face or even anaphylaxis, with a closure of the airways. True food allergies are rare in dogs and most cases of diagnosed “food allergies” are actually food sensitivities/intolerances.
Why do so many dogs suffer from food sensitivities/intolerances?
JD: A major contributing factor can be the constant exposure to just one or two proteins in the diet. Since kibble rose to popularity several decades ago, pet food companies have encouraged repeated feeding of the same product. Consequently, many companion dogs consume one food every day for years, resulting in repeated, long-term exposure to a protein and carbohydrate. Further, these kibbled foods undergo much processing during cooking and extrusion, so the ingredients are frequently oxidized and denatured. Over time, the protein and carbohydrate burden the dog’s immune system, triggering sensitivity. Some dogs may also lack specific chemicals or enzymes needed to digest certain ingredients, while others may have an impaired ability to absorb particular food compounds.
What advice can you give to about decreasing and preventing food sensitivities in dogs?
WJD: Rotating among three or four different types of proteins every few months will give your dog’s body a “vacation” from each source, helping to avoid a sensitivity from forming. If you feed kibble, consider alternating between three or four limited-ingredient formulas, with just one protein and carbohydrate source in each formula. Avoid exposing a healthy dog to “novel”, or exotic, proteins, such as kangaroo, ostrich and alligator. You want to save these ingredients for use in the event the dog develops food sensitivities later in life.
It’s not uncommon for a dog to refuse to eat a particular food but have an otherwise robust appetite. Could this avoidance indicate a food sensitivity/intolerance to the objectionable ingredient?
JD: It’s certainly possible. Studies among numerous species of animals, including humans, show that we form an instinctive repulsion to the taste of foods that we associate with feelings of illness, such as nausea or vomiting. This is referred to as “learned taste aversion”, and it originated as a survival mechanism to protect wild animals and primitive human beings from consuming rancid or poisonous foods. If a wild animal became ill from ingesting a poisonous berry, learned taste aversion could prevent further consumption of the same berries, thus avoiding more severe illness or death. If a dog with an otherwise normal appetite refuses to eat one or two specific foods, she may be telling you that the foods disagree with her. For that reason, I never recommend forcing a dog to eat a food she resists.
Thank you, Dr. Dodds, for your time discussing decreasing and preventing food sensitivities in dogs!