Dog with food bowl

Key takeaway

Signs and symptoms of food allergies in dogs may include itchy skin, hives, gastrointestinal issues, abdominal pain, and lethargy.

Do you know someone who’s allergic to nuts? What if we told you that dogs can also have allergies to food? It’s true—just like humans occasionally  can have an immune reaction to certain foods or food groups, many dogs also struggle with food allergies.

If you notice your dog having a consistent negative reaction to their food, or you try out a new brand of treats and notice concerning symptoms in your dog, it may be a food allergy.

This post covers everything you need to know about dog food allergy symptoms, treatment options, and more. Here’s what you’ll find:

What are the symptoms of food allergies in dogs? Let’s cover the basics. 

Signs And Symptoms Of Food Allergies In Dogs

Like allergies in humans, there are many different signs and dog food allergy symptoms to watch out for. Signs and symptoms of food allergies in dogs might include:

  • Itchy skin. Itching is a common symptom of an underlying food allergy. Pets tend to itch their ears, lick their paws, scratch the sides and armpits, and scoot their rear end on the ground with food allergies. If your dog is scooting their rear end frequently, you may need to have your vet check their anal sacs because anal sac problems are also frequently associated with food allergies. 
  • Skin and ear infections. Skin lesions as a result of itching are a common symptom, manifesting in up to 80% of canine food allergy cases.1 The chronic inflammation from the food allergy and the trauma to their skin from itching can lead to skin infections. Constant licking at the paws can also lead to secondary skin infections and overgrowth of yeast infections. Ear infections are also very commonly associated with food allergies and are sometimes the only sign of an underlying food allergy. 
  • Hives. If your dog consumes something they are allergic to, you may notice hives begin to pop up. Hives can be red patches that are raised and cause itching and irritation. They may be visible if on your dog’s stomach, or if your dog has shorter hair. However, for dogs with longer hair, you may have to use a comb to part the fur and view them, or just feel through the fur for them. Your dog will likely bite and scratch at their hives, which can break the skin and lead to further complications, so it’s important to solve the problem quickly. 
  • Gastrointestinal issues. In some cases, food allergies cause gastrointestinal issues in dogs. The  most common signs are vomiting, diarrhea, excessive gas, or an upset stomach and nausea. If your dog has chronic gastrointestinal issues, this may be due to an allergen present in their food. Since many things can cause diarrhea in dogs, it will be important to work with your veterinarian to find the underlying cause, find out if it is related to a food allergy, and get a long-term solution. 
  • Lethargy. If you notice your dog has less energy than normal or has shown sudden disinterest in their usual activities, a food allergy may be the problem. In fact, lethargy is among the most common signs of a gastrointestinal food allergy.2

Symptoms of Dog Food Allergies

Like all allergies, the only real solution is avoidance of the known allergen. Your vet can help you diagnose food allergies and come up with a treatment plan to prevent reactions from occurring in the future. If your dog is having a severe or life-threatening reaction, it is important to seek immediate veterinary care.

Dutch’s network of affiliated vets are experts in diagnosing and treating allergies in dogs. You can start by making an appointment today and get your dog seen quickly with state-of-the-art veterinary telemedicine. 

Causes Of Canine Food Allergies

The most common source of allergic reactions in dogs is food. In fact, many dogs are allergic to one or more proteins found in different food groups, usually beef or dairy products. In a study published through BMC Veterinary Research, scientists found that these food groups were the most common causes of allergic reactions in dogs1:

  • Beef-34%
  • Dairy Products-17%
  • Chicken-15%
  • Wheat-13%
  • Soy-6%
  • Lamb-5%
  • Corn-4%
  • Egg-4%
  • Pork-2%
  • Fish-2%
  • Rice-2%

List of common dog food allergens

Many dog foods contain beef and chicken, so it’s no wonder why so many dogs struggle with dog food allergy symptoms. Dogs may also have allergic reactions to their environments, such as allergies to pollen, dust, mites, fleas, ticks, parasites, bees, wasps, or other things they encounter while out and about. Figuring out exactly what is causing their allergic reaction can be tricky, so taking a systematic approach to diagnose what they are allergic to is important. 

How To Treat Dog Food Allergies

Unfortunately, there’s no cure for allergies—the best treatment is simply avoiding the causes of allergic reactions. If your dog is currently having an allergic reaction, however, there are medicines that can be used to stop symptoms and help your dog feel more comfortable.

Discovering what food your dog is allergic to may be difficult, especially because most dog food contains a blend of many different proteins. Unfortunately, there is not an accurate test to diagnose a food allergy. While there are several on the market, they are not recommended due to their lack of validity. The only way to “test” is to go through an elimination diet trial. There are two major styles of an elimination diet trial to determine the causes of your dog’s allergy symptoms:

  • Novel protein and carbohydrate diet. This particular elimination diet utilizes a “novel” protein source. Novel means something they have never been exposed to before so theoretically they cannot have an immune reaction to the diet.  During the trial time—typically about 10 weeks—no additional meals, treats, or supplements, including flavored vitamins, are allowed to be consumed3. The issue with this style is many “novel” proteins are used across the various brands of dog food, so it is hard to know what is truly novel. Also, many over-the-counter brands of dog food will have several protein sources in the kibble that are not listed on the ingredients. It’s best for you to conduct the trial together with your vet or nutritionist so you can accurately assess the results3. 
  • Hydrolyzed protein diet. Hydrolyzed protein diets utilize a process where large protein molecules are broken down into much smaller fragments and can bypass the negative immune response and prevent the food allergy. Like the novel protein elimination diet trial, this diet must also be fed for at least 8-10 weeks and no other food items can be given during this time. 

Note: If your dog responds positively to the elimination diet trial and their signs of allergies have resolved, the way to determine what they are allergic to is to perform a “challenge”. The best way to do this is to reintroduce 1 ingredient for a period of up to 2 weeks and see if they respond negatively to that ingredient. For example, if you reintroduce chicken and they get itchy or have diarrhea, stop the chicken and put them back on the hypoallergenic diet. You have just diagnosed that your pet is allergic to chicken. Once they are back on the hypoallergenic diet and no longer displaying the signs of allergies for at least a week, then try the next ingredient, and so on. This is the only way to truly figure out what foods your pet is allergic to.  

Preventative Care Tips

The best preventative care for allergic reactions is to avoid the source of the allergy. Once you determine what causes the reactions, be sure that you only purchase food and treats that do not include the ingredients that your dog is allergic to. 

Graphic with preventative measures for dog food allergies

Dog Food Allergies: Frequently Asked Questions

Dealing with dog allergies can be a difficult thing to navigate. To help you get the answers you need, we’ve answered some frequently asked questions below.

How long does it take for a dog to react to a food allergy?

The time it takes for your dog to react to an allergen can vary depending on the type of allergy as well as its severity. In more severe cases, your dog may have an immediate reaction, breaking out in hives, swelling, and vomiting shortly after ingesting the allergen. In many cases, however, it can take several minutes or hours, or as many as 14 days for your dog to start presenting symptoms. This is often the case for dogs with milder food sensitivities as well4

Can a dog suddenly become allergic to his food?

Just like humans, it’s possible for dogs to develop new allergies later in life. As bodies age and hormones change, it’s possible for your dog to develop a new intolerance or sensitivity to food they may have been eating for years. Dog food allergy symptoms can appear similar to some illnesses and infections, however, so it’s critical that you get your dog seen by a vet as soon as you can if you notice that they have suddenly become allergic to their food. 

How do you treat food allergies in dogs? 

The only surefire way to treat a food allergy in dogs is to avoid the cause of reactions. Once you have found a diet that does not cause a reaction for your dog, the most important part will be to continue this food and resist the temptation to offer new food items and treats. Any new treat can potentially cause your dog to react, so if you do want to add a new food item, be systematic in your approach and monitor for a reaction before adding any new variables into the mix. 

Image of hungry dog carrying food bowl to owner

Final Notes

It can be stressful to see your dog having skin or ear infections and itching as a result of a food allergy and not know what to do. However, with the right attention to your dog’s diet, and consultation with a vet, you can rest assured that you are doing what you can to avoid flare ups and keep your dog healthy and happy.

Dutch makes getting a diagnosis and prescription for your dog simple. Our network of veterinary professionals is happy to consult with you, talk through your dog’s symptoms, review photos, perform a telehealth visit, and prescribe the appropriate medication for your pup. Our service is fast, simple, and affordable. We believe that dogs should live their best lives, free from chronic pain and allergy symptoms. Sign up today to help your dog feel healthier tomorrow. 

Dr. Evans is the Clinical Director of Dutch and the owner of Coastal Animal Hospital.

References

  1. B;, Ballauf. “[Feed Allergy in Dogs and Cats--Not Only a Gastrointestinal Problem].” Tierarztliche Praxis, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/8470106/.

  2. Mueller, Ralf S., et al. “Critically Appraised Topic on Adverse Food Reactions of Companion Animals (2): Common Food Allergen Sources in Dogs and Cats.” BMC Veterinary Research, BioMed Central, 12 Jan. 2016, https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-016-0633-8.

  3. EJ;, Rosser. “Diagnosis of Food Allergy in Dogs.” Journal of the American Veterinary Medical Association, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/8407485/.

  4. Tiffany, Siarra, et al. “Assessment of Dog Owners' Knowledge Relating to the Diagnosis and Treatment of Canine Food Allergies.” The Canadian Veterinary Journal = La Revue Veterinaire Canadienne, Canadian Veterinary Medical Association, Mar. 2019, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6380261/.