Commercial and homemade diets using novel protein and carbohydrates sources have become very common. This trend is due to the popular belief that most allergies are due to specific protein ingredients in the diet. Commercial food with lamb, duck, bison, venison and salmon are now readily available.
Consumer fear of grain gluten has moved many food companies to use potato and sweet potato products as novel carbohydrates.
Actually allergies caused by food represent a small percentage of animals afflicted with allergies. Environmental proteins in pollen, fungus, parasites, dander and dust account for most allergic reactions in dogs. Changing food will not prevent most allergic conditions. Some dogs have both environmental and food allergies and food does reduce the severity of their allergic symptoms.
Establishing environmental or food allergies by specific tests (skin tests, blood test or dietary trials) is important before changing diet. Celiac disease is actually rare in dogs and food sensitivity is probably due to a reaction to something other than grain or gluten in the diet.
Hypoallergenic diets tend to be more expensive, especially those using very exotic proteins, than diets using more common proteins (chicken and beef) and carbohydrates (corn, barley, wheat). Such an increase in food costs for a dog that does not have food allergies is completely unnecessary. More importantly, as the use of novel protein increases more dogs are exposed to them and they become less novel.
Diagnosing allergies becomes more difficult because it requires feeding a protein to which the patient has no previous exposure. As more animals are exposed to wider varieties of protein finding a novel protein will become more and more difficult for veterinarians and dog owners. This may mean feeding meat from animals that are less available and hence more expensive. It may require including animal species that spark a negative public response if they are used as a food source.
Hypoallergenic diets should be reserved for dogs that are proven to be food allergic. Consult your veterinarian before changing to a hypoallergenic food.
Dr. Ken Tudor,
THE DOG DIETITIAN