If your dog is suffering from itchy skin, hair loss, skin infections, recurrent ear infections, or chews on his paws, then he could be one of the growing number of dogs suffering from food allergies. While food allergies can be frustrating to diagnose and may require time and patience to remedy, with perseverance and the help of your veterinarian, your dog can live a long, happy life.
Because food allergies in dogs tend to develop over time, it isn’t unusual for dogs that have been eating the same diet for a long period to begin showing symptoms of an allergy. Studies have shown that the most common culprits of food allergies are beef, chicken, wheat, eggs, corn, and soy. Yes, these most common allergens are often found in commercially prepared pet foods. Dogs suffering from food allergies may be allergic to just one ingredient, or several.
Diagnosing and Managing Food Allergies in Dogs
Symptoms of food allergies can vary in both presentation and severity, which makes diagnosing allergies more difficult. The most common symptoms include itchy skin, hot spots, hair loss, excessive chewing of the paws, and recurrent ear infections. While these symptoms might improve with symptomatic treatments like steroids and antibiotics, they often return as soon as the treatment is stopped.
Because the symptoms of food allergies overlap with those of many other conditions, it is very important to work with your vet to ensure that other underlying issues—such as flea-bite allergies, skin infections, yeast infections, atopy, or mange—are ruled out or treated. If all other causes of your dog’s skin problems have been eliminated, it’s time to consider food allergies as the likely culprit.
Unfortunately, there is no one-stop test or trial to diagnose and treat food allergies in dogs. The best approach to diagnosing a food allergy is through a food trial, where many of the most common allergens are eliminated from the pet’s diet. This “elimination diet” consists of a single source of protein (such as rabbit, venison, duck, or fish) and a single source of carbohydrate (such as potato or rice) that the dog has never eaten before. This diet must be strictly followed for at least 12 weeks to determine whether it reduces the symptoms. During this time, it is essential that this special diet is the only food your dog receives—no treats or table scraps allowed, as these can interfere with the trial.
Your veterinarian will be able to recommend the appropriate trial diet for your dog. Many of these diets are available only through your veterinarian and are made by companies such as Hills, Iams, and Purina. It should be noted that although diets made from lamb and rice are less commonly the culprits of allergies, a lamb and rice diet should not be used for the food trial. These are not considered novel food sources and are less likely to show dramatic improvement.
If you prefer to make your dog’s food at home, you can still conduct a similar trial diet by carefully formulating meals using a novel protein and carbohydrate source. To ensure the homemade diet is nutritionally complete, you may need to consult a veterinarian or veterinary nutritionist to help properly formulate the diet.
If your dog shows significant improvement on the trial diet, you can choose to either keep them on that diet to continue preventing allergies or begin slowly reintroducing trigger foods one by one to see if symptoms return. If no allergic reactions occur after reintroducing a food, then your dog is not allergic to that ingredient. By repeating this process with other ingredients, you’ll be able to select a commercial diet that works without side effects.
While lengthy and sometimes frustrating, conducting a food trial is truly the best way to diagnose a food allergy. Although some companies offer blood or skin testing to help identify food allergies in dogs, repeated studies have shown that these tests are not particularly effective. While blood and skin allergy testing works well for diagnosing inhalant and environmental allergies, conducting a food trial remains the most effective method to accurately diagnose and treat food allergies in dogs.