Itchy, flaky skin. Gas and runny stools. Ear infections and hot spots. While these symptoms may seem unrelated, they can all be caused by the same thing: a food allergy.
If your dog has ever suffered from that constant itch or the red, irritated skin that comes with it, you probably already know that an allergy is likely to blame. And if your dog is constantly battling digestive upset, vomiting, or diarrhea, their food is the obvious culprit.
But just how common are food allergies and what can you do if that is the cause of your pup’s ailments? Those answers are less obvious.
Does Your Dog Really Have a Food Allergy?
Food allergies and intolerances have become popular subjects in the human realm lately. More and more children are developing allergies to nuts and other common dietary staples. And every day a new protein or nutrient is implicated as the reason you’re always so tired or depressed.
So naturally, this same trend has begun to extend to our furry friends. Each new doggy diet that hits the market claims to be free of something that your dog apparently shouldn’t have. If your dog suffers from any kind of chronic ailment, these claims are especially appealing.
But before you start spending all your money on expensive dog diet fads, you first need to determine if your dog’s symptoms are actually caused by a food allergy.
If your dog suffers from chronic itchy skin or chronic intestinal upset, then the odds are pretty high that they are experiencing some sort of allergic reaction. Unlike in humans, who most commonly experience allergy symptoms in the respiratory tract, dog allergies affect their skin and digestive tract first.
That’s because mast cells, the immune cells responsible for triggering allergic reactions, reside in the gut and skin of dogs. While in humans, these cells are most concentrated in lungs and sinuses.
Itchy skin is the most common sign of a food allergy, but environmental allergies and other skin conditions can also cause your pup to itch. You may need to work with your vet to determine the cause of your dog’s itchiness before you try an elimination diet.
But, just because your dog is showing common symptoms of an allergy, like dry, itchy skin, hotspots, ear infections, or loose stools, doesn’t mean their food is to blame. In fact, most dog’s suffering from allergies are allergic to something in the environment, like dust mites, pollen, or flea saliva.
Only about 10% of dogs who suffer from allergies are actually allergic to something in their food. So how do you know if your dog’s diet is the cause of their allergy symptoms?
If your dog only has symptoms at certain times of the year, or if the symptoms come and go even when their diet remains the same, you are likely dealing with an environmental allergen. But, if your dog’s symptoms are consistent throughout the year, food might be to blame. Food may also be the problem if your dog’s symptoms have steadily gotten worse and you haven’t made any changes to their diet.
Even if it is something in your dog’s food that’s causing their symptoms, that doesn’t necessarily mean your dog has a food allergy, though.
The Difference Between an Allergy and an Intolerance
Just like in humans, dogs can suffer from both food allergies and food intolerances. While these two issues present with similar symptoms, they are actually very different.
Not sure if your dog is allergic to the food going into their mouth or just sensitive to it? Luckily, an elimination diet will help in either case.
When your dog’s system perceives a foreign body as a threat, the immune system is triggered to fight and isolate it. This process is normal in the presence of an attacking virus or bacteria, but abnormal if the trigger is something harmless like a dust particle or food ingredient. We call this type of abnormal immune reaction an allergy.
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Food allergies most commonly present with itching, irritated skin, hot spots, or chronic ear infections. Occasionally, they can be accompanied by gastrointestinal symptoms as well.
Food sensitivities, on the other hand, do not involve the immune system. Instead, the issue lies within the digestive tract. Your dog may not create enough of a particular enzyme to digest certain foods. Or certain foods may cause excessive gas or irritate your dog’s stomach.
Food intolerances can also cause itchy skin but are more likely to cause digestive issues including vomiting, diarrhea, and gas.
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Luckily, whether your dog is suffering from a food allergy or a food intolerance, a properly conducted elimination diet will help them find permanent relief.
Conducting Your Own Elimination Diet
If you believe your dog is suffering from symptoms related to a food allergy or intolerance, removing the culprit from their diet will relieve their symptoms. It is not a quick or easy process, but, when done properly, an elimination diet is the most effective way to help your dog overcome these debilitating ailments.
Before you begin your dog’s elimination diet, check out this video to learn more about reading dog food labels and ingredient lists.
Step 1: List all possible food allergies
Your dog can develop an allergy or intolerance to any food they have been exposed to. This means, in order to remove all potential allergens from their diet, you first need to figure out every ingredient they have ever eaten.
If this sounds like a monumental task, you’re right. If your dog has always eaten the same dog food, it’s a little easier than if your dog has switched between different brands or formulas in their lives. In either case, you also need to include any treats your dog has ever eaten, including table scraps.
Start by making a list of any proteins you know your dog has consumed. Look at their current food. Write down any animal proteins listed on the ingredients list. Next, look up the ingredients lists of any previous diets they have been on. Then look at any treats they have gotten and write down the animal ingredients used in those. Make sure to include human treats like lunch meat or hotdogs.
Dogs are most often allergic to animal proteins, with beef, dairy, and chicken being the most common offenders.
But dogs can also be allergic to plant proteins and other nutrients. In fact, grains are one of the most common causes of food intolerances in dogs.
While putting together the list of your dog’s possible food allergies, don’t forget to include any human foods they have received in the past.
Once you have written down every animal protein your dog has eaten, add to that list every major plant ingredient they have consumed. Many dogs have issues with wheat and corn. But other grains and even fruits and vegetables can cause problems. Scan the ingredient label of any dog foods and treats your pup has eaten and write down anything that’s not a vitamin or mineral.
While it is possible for dogs to be allergic to micronutrients, it is much less likely. And, listing every synthetic vitamin in every food item your dog has eaten in their life would take longer than it’s worth.
Once you have a list of every possible allergen, you are ready to move on to step 2.
Step 2: Find a novel food
Once you have a list of every major animal and plant ingredient your dog has ever eaten, then you need to find a diet that includes only ingredients not on that list.
Depending on the length of your list, this might be fairly simple or incredibly difficult.
Nowadays, there are a ton of limited ingredient dog diets available for sale. Most of these contain one animal protein and one plant ingredient such as “lamb and peas” or “venison and sweet potatoes.” As long as none of the ingredients listed are on your potential allergen list, one of these diets might be a good choice for your “novel food.”
Seem like there’s nothing left for your dog to eat after accounting for all possible food allergens? You may have to hunt down meats and carbs rarely used in dog foods and create your own homemade diet to complete your elimination trial.
Not all commercial limited ingredient diets are created equal. Many claim to be limited or hypoallergenic, but actually contain a lengthy list of ingredients. And even more of them contain low-quality ingredients that can cause additional problems for your pooch.
If you’re looking for a commercial limited ingredient diet to use as your elimination diet, we recommend the following:
- Instinct Limited Ingredient Diets – This line comes in four recipes, each with only one quality animal protein and one vegetable. Great for dogs with a long list of potential animal protein and plant allergies.
- Merrick Limited Ingredient Diets – This line comes in five recipes, each contains only one animal protein and a short list of vegetables. Great for dogs with a long list of potential animal protein allergies.
- Canidae Pure Diets – This line comes in multiple recipe types, each containing a short list of animal and plant ingredients. Great for dogs with only a few potential allergies.
If your dog has an especially long list of potential allergies, your best bet for a novel diet may be one that is homemade. This allows you to choose a single novel animal protein, such as elk, bison, or rabbit, and a single plant ingredient, such as sweet potato, oatmeal, or quinoa. You should add a commercial dog multivitamin supplement to this mix as well, just make sure there aren’t any possible allergens in that ingredient list either.
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If you go the homemade dog food route, even with the added supplement, it’s unlikely the diet will be complete and balanced. You will only need to feed this diet for a few months, so it shouldn’t cause any issues. But do keep in mind, you will need to switch to a complete diet after step 4.
Step 3: Wait for symptoms to clear
Once you have found a diet that contains no possible allergens, start transitioning your dog off their current diet and onto the new one. Do this by mixing one part new diet to three parts old diet for a couple of days. Then do one part new to two parts old for a couple of days. Then one to one. Then two to one and so one.
If your dog sneaks a snack during their elimination diet and their symptoms do not clear after a few months, that snack may be the reason. Keeping a tight lid on the food your dog has access to during this time will help avoid any confusion over what may be causing their itchiness.
After a week or two, your dog should only be getting the new diet. Make sure they aren’t receiving any treats or human food, either.
You will need to feed this novel diet exclusively until all your dog’s symptoms clear up. For digestive symptoms, this should only take a few weeks. For skin-related symptoms, this could take up to three months.
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Once your dog is symptom-free, you can move on to step 4. If your dog is still showing symptoms after three months, it’s possible they have an allergy to something in the new diet. Try switching to another limited ingredient novel diet that has completely new ingredients. For instance, if you were feeding lamb and sweet potato, try feeding duck and quinoa instead. You may have to switch from a commercial diet to a homemade diet.
Try this new novel diet for three weeks to three months. If symptoms still do not clear up, it’s most likely that your dog does not have a food allergy. They may be suffering from environmental allergies or undiagnosed disease. In this case, transition them back to a quality, balanced diet and talk to your vet about what other steps to take.
Step 4: Reintroduce possible allergens
Once your dog is symptom-free, you are ready to reintroduce possible allergens.
If your dog is currently on a limited ingredient diet that is complete and balanced and doing well, this step isn’t entirely necessary but we still recommend you do it. The more “safe” foods you know your dog can eat, the more variety they’ll have in their diet. Different foods provide different nutrient profiles. Exposing your dog to a wider variety of foods reduces the odds that they’ll be deficient in any one nutrient.
Does your dog love a particular treat? Don’t forget to reintroduce each ingredient in that special snack one at a time before adding the treat back into their diet. If they show allergy symptoms during any of those reintroductions, it’s time to say goodbye to that snack for good.
To reintroduce possible allergens, simply pick a food off your list that you made in step 1 and start adding it to your dog’s diet. It’s best to start with an animal protein that your dog is unlikely to be allergic to. Since beef, chicken, and lamb are the most common allergens, avoid those at first if possible.
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You can add this new ingredient by finding a commercial diet that contains the two novel ingredients you were feeding before plus only this third ingredients. Or, you can continue to feed your novel diet from step 2 and add this third ingredient in whole food form. For instance, if I want to reintroduce turkey to my dog’s diet, I could add ground turkey from the supermarket to the kibble I started feeding my dog in step 2.
Feed your dog this new diet for at least 30 days. If your dog does not develop any allergy-like symptoms in that time, you can assume this reintroduced ingredient is safe. Add it to your “safe foods” list along with the two ingredients from the diet you used in step 2. Then, reintroduce another single ingredient from your possible allergens list.
If your dog does develop any symptoms to the added ingredient, remove it from their diet immediately and feed only safe foods until all symptoms subside. At that point, note the offending ingredient on a “definite allergies” list. Then, reintroduce a new ingredient from your possible allergies list and start the process over.
Continue adding new ingredients every 30 days until you feel you have a wide enough variety of foods to feed your dog a complete diet.
Step 5: Find a complete and balanced diet
Once you have reintroduced a wide variety of foods, you can look for a new complete and balanced diet to feed your dog. Make sure this new diet only contains foods on your “safe foods” list plus added vitamins and minerals.
With the right guidance, you can provide your dog with a balanced, allergen-free homemade diet. But make sure you do your homework and seek the help of a professional if needed to assure your dog gets all the nutrients they need to thrive.
Transition your dog slowly onto this new diet just as you did before.
If your dog is already on a complete and balanced diet, you can continue to feed that and use your safe list to add variety to your dog’s diet through treats and healthy human food snacks.
Always make sure to double-check the ingredients list every time you get a new bag of food. Companies will occasionally change their recipes without warning and might add an ingredient your dog can’t have.
If your dog’s list of “safe foods” is relatively short, you can always work with your vet or a dog nutritionist to create a complete and balanced homemade diet. It is possible to make both cooked and raw diets at home that will keep your dog thriving.
Feed to Prevent Food Allergies
Once your dog’s allergy symptoms are in the past, you can breathe a big sigh of relief. But don’t get too comfortable. Allergies and intolerances can appear at any time and in response to any food your dog has been exposed to. And dogs who have allergies already are more likely to develop future allergies.
To help your dog stay symptom-free, avoid foods that are overly processed or made with poor quality ingredients.
Proteins that have been heated, rendered, or otherwise overprocessed can become unrecognizable to your dog’s system, resulting in an allergic reaction. Raw, freeze-dried, and dehydrated foods are less processed than kibble and canned foods and might be a better choice for allergy-prone dogs.
Don’t let debilitating allergy symptoms hold your dog back from enjoying their life. An elimination diet is a lot of work, but it is worth it to help your pup find relief!
Adding probiotics to your dog’s diet is another way you can help keep their immune system on the right track and allergies at bay. This is especially important after your dog goes through a round of antibiotics or any stressful situation.
Whatever food type you choose, make sure it is made with quality ingredients. If you can’t read the ingredient name or you don’t know what type of meat is listed, find a different food. Not only will doing so reduce the likelihood of your dog developing allergies, but a higher quality food will help your dog thrive in all aspects of their life.
Sara Seitz has spent most of her life in the pet industry and has a bachelors in animal behavior from Colorado State University. Sara started working with dogs and cats as a high schooler at a rural boarding kennel. There she learned a lot about the bad and the ugly of the pet service industry. But not even the toughest day at that job would dissuade Sara from following her dream of working with animals.
In college, Sara got a job at a dog daycare and boarding facility in Fort Collins, Colorado. Her new career provided even more opportunities for learning about dog behavior than her classes did. As general manager of the daycare, Sara helped the company launch a new in-home pet sitting branch and trained to become a certified dog trainer. Between shifts taking care of peoples pets in-home and supervising dogs during playtime at the daycare, Sara organized and taught obedience classes.
Sara has always been passionate about bettering the lives of our canine companions. She soon found that advocating for and educating owners in the power of positive reinforcement training was one of the best ways to help dogs and their owners live happier lives.