It is estimated that of 100 dogs with skin problems, one dog has a true food allergy causing signs of skin disease, most commonly, pruritus (itching). Food trials with a hypoallergenic diet are currently the method or test for diagnosing food allergies by identifying which ingredient(s) is the cause. Many steps must be followed to ensure accurate results. Therefore, food trials should be done under your veterinarian’s guidance.
Hypoallergenic simply means the diet does not contain the ingredient thought to cause the reaction. Hypoallergenic does not mean the food contains anything that will actively treat or cure the allergy.
For a food trial to be valid, all ingredients from previous and current diets must be avoided, including treats, chewable medications that may contain beef and other common dog food ingredients. Skin medications, such as steroids and antihistamines should also be stopped as per your vet’s direction. Before widespread marketing of lamb and rice diets, “hypoallergenic” was synonymous with lamb and rice. For dogs that have eaten standard dog food in addition to lamb and rice, hypoallergenic diets are more difficult to create. In these cases diets based on rabbit, fish, deer and duck are the next step. Commercial formulations of these ingredients are available from a few manufactures.
Standard commercial dog foods contain beef, poultry, fish and or horsemeat along with wheat and or corn. Take note that some lamb/rice diets contain beef, corn, eggs, as well as other ingredients typically found in commercial diets. In order to be hypoallergenic the diet should be free of colorings, flavorings and preservatives. Best results are achieved with diets consisting strictly of ingredients rarely or never before consumed.
When changing to a hypoallergenic diet begin with very small amounts of the new diet. Gradually increase the new diet portion while decreasing the former diet. After two or three weeks, the dog will be eating only the new hypoallergenic diet. This adjustment period will also help to avoid dietary-induced diarrhea. Be patient for results. Typically, dogs with food allergies require eight weeks or longer to improve noticeably once the hypoallergenic diet is the sole source of food.
Assuming the food trial is conducted right and symptoms resolve, individual ingredients from previous foods are added one by one to the hypoallergenic diet. If the dog is allergic to an ingredient, the skin problem will flare up. In this way the ingredient(s) causing the allergy can be permanently eliminated from the dog’s diet.
Many owners feed their dog a special diet, typically formulated with lamb and rice, with the belief they are alleviating food allergies. Be aware that allergies to lamb and rice also occur. Because more dogs are consuming lamb and rice, we can expect to see more dogs developing allergies to these foods. There is evidence that lamb may be more likely to produce allergies in some dogs than the usually source of protein found in dog food. While there is no problem with feeding a balanced diet based on lamb and rice, you should know that neither is there anything magical about the ingredients.
Because so many factors interact to cause skin problems, diagnosing a true food allergy requires much more than merely changing diets and passively noting improvements. With patience, will power and perseverance, you will both feel better.
Compliments of Don Payne, Gardon Pet Center, 301-217-0432.