By Dr. Roger De Haan, DVM
Itching is the most common sign of food allergy in dogs. However, all itching is not food allergy induced. How can we tell when it’s food and when it’s something else?
Veterinarians are trained to look for causes and there are many things we do to determine the cause of itching. We thoroughly examine the dog, plus we ask lots of questions. First we have to eliminate the obvious possible causes, like fleas. We ask, “Is the itch seasonal or is it year-round?” If it’s seasonal, we might suspect inhalant pollens, weeds, trees or flowers. But if it’s year-round, we begin to suspect food.
Also, if the itch is year-round, we must consider house dust and mold. Anything else in the house could also be a suspect, like the rug, the plastic feeding dish, even drinking water. I’ve been surprised when I see how often house dust and mold are a factor. However, that problem is harder to solve. There are answers, but it takes more work and ingenuity than changing the diet.
Usually the easiest factor to change is the food, so that is the best place to begin. The diagnosis of a food allergy is often made by feeding your pet a type of food he/she has never eaten before. Sometimes this means home-cooking. Lamb and rice is a favorite to begin with for dogs with a chronic itch and it is commercially available. Even baby food can be used, especially with miniature breeds.
The offending allergen could be either a major or minor component of your dog’s food. The common major allergens are: corn, wheat, soy, chicken, beef, eggs and dairy. But several minor components could be just as guilty: a preservative, coloring agent, food stabilizer or even an insecticide used by the farmer or feed dealer to spray his grain.
So where do you begin? Start by consulting your veterinarian. Make sure you dog is basically healthy and that the symptoms generally fit what could be a food allergy. Then you begin what is known as a “food trial.” You choose what to feed your dog from a list of hypoallergenic food items. For protein, you could include turkey (a cooling food in Chinese medicine), duck, lamb, rabbit, or venison. The grains or carbohydrates could be rice—or if that is an allergy suspect, then oatmeal, millet, sweet potatoes or squash. I often recommend about 25% vegetables in the form of cooked or steamed carrots, green beans, broccoli, leafy greens, zucchini, peas, etc. Veggies are usually non-allergenic and most dogs will eat them.
Since proteins are especially allergenic, the meats should not be over 35% of the diet. The grains or potatoes can be about 20-35%. And as mentioned, veggies should be about 25-30%. The health status of your dog may dictate some changes in these percentages.
That is where you veterinarian comes in. Because every pet is an individual, individual health problems must be taken into consideration. And some dogs will need additional fatty acids (Omega 3 oils), minerals or other supplements during their food trial.
What not to feed your dog during the food trial is just as important as what to feed.
1. Feed no other snacks, junk food, table food, rawhide chews, etc. No cheating during this test! If you cheat, you may have to start all over again. For instance, one client’s dog was doing great until one accidental feeding containing corn, a known allergen for that dog, and immediately the itch cycle began again. His owner had to guard against hidden corn, even corn syrup, or lose the battle.
2. Use a top quality bottled or filtered water.
3. Replace plastic bowls with ceramic or stainless steel.
4. Keep daily records. If food is the major culprit, you will usually notice improvement within 10 to 20 days. Occasionally it may take one month. Note any change in chewing, scratching, skin color, skin quality and scaliness.
5. Note that an allergic dog may be sensitive to several different substances simultaneously. Allergy is considered an immune mediate problem, so in time many allergens may be involved. That could include various foods and flea saliva as well as airborne pollens. If changing the diet does not help (and sometimes it won’t), you at least began at the most logical place and were doing something healthy and nontoxic. Your next step would be to look into other causes, which are beyond the scope of this article.
If it’s a year-round problem, you will still want to stay on a better-than-average diet. Or you may even decide to try a second food trial. As lamb and rice diets are becoming more popular, we are finding a few lamb and rice allergies. Also, some of the lamb and rice commercial diets are not truly hypoallergenic. For instance, some of them have corn and other questionable by-products in the formula. The water source in the canned variety may have chemicals to which your dog could be sensitive. You may have to get really strict.
The next steps may require professional help and decisions. Allergy testing is quite expensive, but may be useful. These tests are about 70% accurate. I use a method common among holistic practitioners called biokinesiology and have been very pleased with the accuracy. Although no test is 100% accurate, most of them will get you moving in the right direction.
Some food allergies are really nutritional problems. There may be faulty metabolism of fatty acids, of zinc, etc. Some dogs require twice as much as others—higher than the label says the average dog needs. It may also be that the digestive enzymes or bile acids are insufficient to properly metabolize the foods eaten. The dog becomes allergic to by-products of food, which are improperly metabolized. These are special cases, but they certainly warrant consideration. In that case, a special diet and special supplements are indicated.
Much more could be said about food allergies affecting the skin. Some dogs respond quickly and completely. Others are stubborn chronic cases to crack. Frequently these dogs respond to acupuncture. Others require thyroid supplementation. Many respond to allersodes, a type of allergy desensitization. Several years ago I began using a technique pioneered by Dr. D. Nicolleti called R.I.D., using a cold laser on specific neural and allergy points with very encouraging results. (A photo of me administering this treatment appears at the top of this page.)
Dr. Roger De Haan has been a veterinarian for over 40 years. While his practice, Holistic Veterinary Services, is located in Kings Mountain, North Carolina, he has clients across the United States who use his phone consultation service. Pre-arranged phone consultations are available by calling his office at 704-734-0061. Once the phone appointment is made, you have the option of faxing a copy of your dog’s blood tests, history and/or notes the previous day or evening with a cover letter. Consultation costs will include Dr. De Haan’s time studying the information so that he can discuss all relevant information and recommend a plan for natural therapies, supplements, dietary changes, homeopathic remedies, enzyme supplements, herbal remedies, massage or magnetic therapy, etc. All of these can be safely applied at home in addition to and with any concurrent treatments by your local veterinarian.