Food Allergies in Dogs
An allergy is a disorder of the immune system often also referred to as atopy. Allergic reactions occur to normally harmless environmental substances known as allergens; these reactions are acquired, predictable, and rapid. Animals can have allergies to inhalants, ingestants, contactants, injectants, infectants, physical agents, and mold and fungi. Genetic factors as well as emotional stressors can cause and contribute to animal allergy (Nambudripad, 2006). Food allergy is the third most common allergy in dogs and usually appears in 33 percent of dogs less than one year of age. Food allergies are caused by substances that are taken in through the mouth and go into the gastrointestinal tract. These substances can include food, condiments, food additives, preservatives, food colorings, chewing gum, beverages, drugs, antibiotics, and vitamins and other supplements. But, some breeds of dogs Viz. Terriers, Golden Retrievers, Labradors, Boxers, and Bulldogs are more prone to allergic skin diseases, although all purebreds have some risk for allergy (Macropoulos, 2007; Pet Education, 2007).Trik Android
Allergens for Food Allergies
The most common allergens in dog food includes,
- Dairy products
Symptoms of Dog Food Allergies
Dogs with allergies frequently chew on their feet, rub their face in the carpet or on furniture, scratch their bodies, have recurrent ear infections, and have mutilated skin and hair loss. They may also wheeze and have a runny nose and eye discharge (WorldNow, 2006.)
- Dermal Symptoms
Nonseasonal pruritis and dermatological lesions including papules and erythema; secondary lesions of epidermal collarettes, “hot spots,” hyperpigmentation, and seborrhea are symptoms of food allergy in the dog.
- GI Symptoms of Food Allergy
It includes colitis, fecal mucus, fecal blood, tenesmus, and increased fecal frequency.
- Neurologic Signs
It includes signs such as malaise and seizures.
Diagnosis of Food Allergies
The diagnosis of food allergies is difficult because many other problems can cause similar symptoms. A complete medical history and physical examination is essential. The veterinarian has to examine the skin closely and inquire about dog’s dietary history.
- Elimination Diets
The trial diet should be fed for up to 3 months. If marked or complete resolution in the
Pruritis and clinical signs occur during the elimination diet trial, food allergy can be suspected. To confirm that a food allergy exists and that the clinical improvement was not just coincidental, the animal must be challenged with the previously fed food ingredients and a relapse of clinical signs must occur. The return of clinical signs after challenge is usually between 1 hr and 14 days, although it is sometimes within 3 days. Once a food allergy is confirmed, the elimination diet should be reinstituted until clinical signs resolve, which usually takes <14 days. At this point, previously fed individual ingredients should be added to the elimination diet for a period of up to 14 days. If pruritis recurs, the individual ingredient is considered positive for having a causative role in the food allergy. If pruritis does not recur the individual ingredient is not considered important in causing the clinical signs (Merck & Co., 2008).
- 2. Blood Testing
Blood tests such as RAST test or ELISA test can be performed to diagnose food allergies.
- Intradermal Skin Testing
Skin testing can also be performed. Although these tests are routinely performed and used as a diagnostic aid, there is no evidence that these tests are reliable for the diagnosis of food allergies. Food trial is the only effective diagnostic aid for food allergies.
Treatment for Food Allergies
But many times, avoidance is the best therapy. About 80 percent of food allergic patients can be managed with commercial diets. When avoidance is not feasible, cortisone-like drugs (corticosteroids) may be used. Some food allergic animals, however, respond poorly to corticosteroids and, as a general rule, the efficacy of this type of therapy tends to decrease. Response to antihistamines and fatty acid supplements usually is limited. Hypo sensitization or allergy shots are not an effective form of treatment for food allergy.
Once the dog has been diagnosed with food allergy, necessary alterations should be made in its diet. The most commonly recommended diet for dogs with food allergies is a novel protein diet. It comprises of a protein source which the dog has never eaten before.
Potential Novel Proteins Includes,
- Fish (such as salmon)
Different diets can also be used having specific characters to avoid against food allergy,
1. Hydrolyzed Protein Diets
Hydrolyzed protein diets are diets in which the protein content has been synthetically reduced. The basic idea behind feeding a hydrolyzed protein source is that the proteins in the food are small enough so that the allergic dog’s immune system does not recognize the protein fragments.
- Homemade Meals for Dogs with Food Allergies
Many dog owners prefer homemade meals during food trials. Care should be taken that these meals contain a novel protein source which the dog has not eaten before. A carbohydrate source such as rice or sweet potato can also be added to the meal. If the feeding trial is successful and the homemade diet is to be continued, it is important to ensure that the diet is properly balanced to provide all the nutrients a dog needs to maintain a good health (Kulkarni, 2010).
Kulkarni, A. (2010). Food Allergies in Dogs. Buzzle.com.
Macropoulos, A. (2007). Does Your Pet Have an Allergy? Fox Health News, http://www.foxnews.com/printer_friendly_story/0,3566,293381,00.html.
Merck & Co. (2008). Food Allergy, Whitehouse Station, NJ USA.
Nambudripad, D.S. (2006). Eliminate Your Pet’s Allergies. Buena Park, CA: Delta Publishing Company.
PetEducation (2007). Allergies and Atopy. Veterinary & Aquatic Services Department, Drs. Foster & Smith, Inc.http://www.peteducation.com/article.cfm?cls.
World Now (2006). Pets can have allergies too. Associated Press. WorldNow, 2002-2007. http://www.kristv.com/globalstory.asp?s=5614305 .