Dogs can develop allergies suddenly, even if they have eaten the same foods for years. Bruce Novotny, DVM, at Woodhaven Labs says that food allergies can damage the gastrointestinal tract and may cause conditions such as colitis, an inflammation of the large intestine. There are several methods for identifying and controlling food allergies in dogs.
Beef is one of the most common food allergies in dogs because of its high protein content. Diane Morgan, the author of The Basset Hound Owner's Survival Guide, explains that proteins are often a problem for dogs because they have large molecules that can combine with an antibody to produce an allergic reaction.
Some symptoms of a beef allergy are itching and redness. However, the results can be more severe. Morgan notes that the dog's oil-producing sebaceous glands may overreact because of the allergy, triggering a secondary bacterial skin infection called pyoderma.
Wheat and Dairy Products
Wheat can cause an allergic reaction in dogs. The symptoms of a wheat allergy, according to the Wheat Free website, are itching of the skin and anus, inflammation in the ears, vomiting, diarrhea and front paw licking. Many dog food brands contain wheat, so it can be difficult to avoid.
The Allergic Pet website indicates that dairy products are another common allergy trigger. The symptoms of dairy allergies are itching, vomiting and diarrhea.
Diagnosis and Treatment
A dog with a suspected allergy may need to spend several days on an exclusion diet, eating only ingredients that he has not eaten before, to try to rule out the source of the allergen. If his symptoms improve on the exclusion diet and then worsen when he is reintroduced to the food, that food is the source of the allergen. Another method of identifying a food allergy is by having a veterinarian perform a blood allergen test. The only way to cure a food allergy is by avoidance, so Allergic Pet recommends purchasing a commercial hypoallergenic dog food that does not contain the substances that trigger the dog's food allergy.
Pet Education indicates that no treats should be offered outside the recommended diet because they may cause a recurrence of allergy symptoms. Rawhide, pig's ears and other chews can be allergen triggers and should be avoided. In addition, flavored toothpastes and toys should not be used, and medications that contain flavoring agents should also be removed from the dog's diet. Finally, the website recommends keeping the dog out of the kitchen during meal preparations in case food falls on the floor.