What Should I Feed My Dog If He Has A Food Allergy?
A dog who itches and licks himself all the time can be super annoying to deal with  and its painful to watch him suffer so much! And sometimes, the cause of his allergies can be due to things other than pollen and fleas. Though not super common, its totally possible that your dog is allergic to something in his food. If your vet suspects your dog has a food allergy, its likely theyll run a food trial with your dog that requires him to eat one or more different foods for a while. The Dodo reached out to Dr. Lori Hammond, a veterinarian at the VCA Mission Animal and Bird Hospital in California, to find out. A food allergy is a hypersensitivity reaction usually to a type of protein within the dogs diet, Dr. Hammond told The Dodo. The immune system identifies proteins within the food as allergens and creates antibodies that attach to mast cells, which then release histamine and other chemicals upon repeat exposure, that then cause the dogs clinical signs of food allergy.  So basically, if your dog is allergic to an ingredient, the immune system will try to attack it every time he eats the food, which causes all the annoying allergy symptoms your dog has to deal with. Food allergy vs. food intolerance  Keep in mind theres a possibility that your pets reaction is due to a food intolerance instead of a food allergy. A food intolerance basically just means your dog has trouble digesting a certain food. Both have really similar symptoms, but the main difference between the two is that an allergy involves the immune system, while an intolerance doesnt. Your veterinarian can help you determine if your dog has a food allergy or a food intolerance. Its tough to know if your dog is allergic to his food or something else in his environment, since your dog will react basically the same way to both. Identifying food allergies can be challenging, as dogs with allergies often present similarly no matter the underlying cause of their allergies, Dr. Hammond said. To confirm whether your dog is allergic to something in his food, your veterinarian might recommend running a food trial. Under the guidance of your veterinarian, a novel protein diet or diet trial is the best way to definitively identify a food allergy, Dr. Hammon said. To run a food trial, you would feed your dog a limited-ingredient or hypoallergenic diet over an 8- to 12-week period. If he stops having reactions during that time, and then reacts again after reintroducing his old diet, you have a confirmed food allergy, Dr. Hammond said. Limited-ingredient diets  A limited-ingredient diet (LID) is formulated with fewer ingredients than are typically found in your standard dog food, and is usually formulated with an exotic protein and atypical sources of carbs to avoid common allergy triggers. The point of a LID is to stop the allergic reactions so your vet can confirm that your dog has a food allergy. In order for it to work, though, you need to know exactly what your dog has eaten in the past, so you can feed your dog a protein hes never had before (since your dogs reaction wont be caused by something hes never been exposed to). If a complete diet history is known, it is sometimes possible to do a novel protein diet where the dog is given a protein it has never been exposed to, for instance lamb, Dr. Hammond said. But finding a protein your dog hasnt eaten isnt as easy as youd think. Unfortunately, finding novel proteins these days has become challenging, as many boutique and commercial diets are starting to use proteins such as lamb, duck, bison, etc., that were not previously common in everyday dog food, Dr. Hammond said. This makes finding a protein a dog has never been previously exposed to difficult.  Not to mention the fact that cross-contamination is possible in LID. Just because a diet is labeled as a lamb diet or similarly novel protein does not mean other proteins can not be found in that diet, and often diets are produced on the same equipment without appropriate cleaning in between production to prevent cross-contamination, Dr. Hammond said. This can lead to confounding results and would not represent a true diet trial. That is why it is so important to always work with your veterinarian when choosing the right diet for your pet.  For these reasons, veterinarians often recommend hypoallergenic diets for food trials. Hypoallergenic diets  Hypoallergenic diets are prescription foods where the protein is formulated to be so small it can pass through the body undetected by the immune system. Some owners having battled signs of allergies for so long often choose to stay on the hypoallergenic diet rather than trying to determine the specific cause of the allergy, as they are just relieved to have a non-itchy dog! Dr. Hammond said. Best dog food for allergies  There are many available veterinary diets for food allergies, which is great because not every dog will like every diet, Dr. Hammond said. The most common diets she recommends for food trials are the Hills z/d, Purina HA, Royal Canin HP and Ultamino lines. Most of these companies also make treats that are also hypoallergenic, so you do not have to feel like you are depriving your dog, Dr. Hammond said. These diets are recommended because they are specifically formulated for diet trials and meet all nutritional requirements for your dog, as well as meet specific guidelines to avoid cross-contamination, Dr. Hammond added.