Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Food Allergies in Dogs: Our Vet Explains Signs, Causes, Diagnosis & Care

Share

Labrador watching his food

Food allergies are a type of allergy that can affect dogs, causing chronic skin and digestive signs. Some breeds are more prone to food allergies than others, but any dog can be affected. When a dog has a food allergy, their immune system overreacts to a certain food ingredient in their diet, typically a protein, called allergen. The body recognizes this ingredient as a foreign invader, producing antibodies and an immune response to an otherwise normally tolerated food.

Dog food allergies develop over time; the body needs to be exposed to the food ingredient for a long period of time before developing the full reaction. That is why dogs that have eaten the same food for months or years develop an allergy to it and can’t be fed that same diet anymore.

In this article, we’ll explain in a clear way the science behind food allergies so that you can learn more about how to identify, diagnose, and treat this problem, with the ultimate goal of improving the health and well-being of your beloved dog.

divider dog paws 4 oct 2024

Signs of Food Allergies in Dogs

dog scratching
Image Credit: schubbel, Shutterstock

The most common sign of food allergies in dogs is chronic skin problems. Itchiness is very common. However, the itchiness can develop into something worse as the dog continues to scratch. Eventually, the skin will look red, inflamed, and sore. If the dog continues to scratch, secondary infections will set in. Chronic inflammation of the ears (otitis) can also occur.

Dogs may also experience digestive signs, such as soft feces, flatulence (gas buildup), abdominal pain, intermittent diarrhea, blood, or mucus in the stools. Vomiting can occur as well; however, this is rare.

It is important to note that, quite commonly, dogs may suffer from multiple allergies at the same time, such as environmental allergens or flea saliva. This can aggravate the clinical signs and cause occasional flare ups of itchiness (pruritus) in affected dogs.

What Ingredients Are More Likely to Cause Allergies?

Proteins are by far the most common cause of food allergies in dogs. Out of all the proteins, dogs are most likely to be allergic to beef, dairy, chicken, wheat, lamb, and egg. In order to develop an allergy to an ingredient, your dog must have been exposed to it for a period of time. However, you don’t need to avoid these ingredients if your dog isn’t allergic to them. They won’t harm your dog unless their body recognizes them as a foreign substance.

How Are Food Allergies Diagnosed?

Dog check up

Diagnosing food allergies requires a team effort between you and a vet. There isn’t a test the vet can run to determine what exactly your dog is allergic to. Instead, a vet can diagnose food allergies based on your dog’s physical examination, their clinical history, and their response to a food trial.

The instructions for these trials are pretty straightforward and simple. First, your dog should be fed a special diet (called an elimination diet) for 8 to 12 weeks, and no treats or other foods are allowed during this time. The diet chosen should be hypoallergenic for your dog, which means that it contains a protein your dog has never eaten before or it contains proteins that have been hydrolyzed.

The typical proteins used for this purpose are venison, rabbit, or fish. However, finding the right diet can be challenging because there are only so many options on the market, and many companies use similar ingredients. This is why homemade diets can play an important role as an elimination diet. The vet will recommend you to use a single protein and a single carbohydrate source to be fed during the trial. These diets are not suitable for long-term management since they lack important nutrients that your dog needs.

You and the vet may choose to do the food trial using a protein hydrolyzed diet. These are commercial diets in which the proteins have been treated to reduce their size to smaller peptides and amino acids, which can’t be recognized by the dog’s immune system, making it unable to trigger an allergic response to them. These types of elimination diets are suitable to be fed long term if necessary because they are nutritionally balanced and complete.

If your dog’s health problems improve while they are fed the elimination diet and deteriorate once you introduce their old diet back, a food allergy can be diagnosed. This step is called a food challenge. Once you start feeding your dog again the elimination diet and they are free of allergy signs, guided by a vet, you can very gradually start introducing food ingredients (provocation testing) until their skin or digestive system flares up again. This can be the way to diagnose exactly the proteins that cause your dog’s allergies to make your choice for the long-term diet your dog will eat.

If you are concerned about the health and well-being of your pet, seek veterinary advice for the best course of action.

Did you know you can speak to a veterinarian without having to travel? Just head over to PangoVet. It's our online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content Savings V1

How Are Food Allergies Treated?

The only way to treat food allergies is to avoid whatever your pet is allergic to or to feed a commercial protein hydrolyzed diet. You can choose a new diet that doesn’t contain whatever food ingredient your pet is allergic to if you successfully found this out. There are many commercial diets available that are made with limited ingredients.

Can Food Allergies Be Cured?

Dog eating happy
Image Credit: alexei_tm, Shutterstock

No. The dog will be allergic to the food ingredient(s) for the rest of their life. However, they can be managed long term with the right diet and avoiding the allergens. Luckily, most pets only require a hydrolyzed protein diet or a diet with limited ingredients. For most dogs that are allergic to a single protein, avoidance is quite easy. The diet they can eat will not contain this ingredient. Of course, for dogs that are allergic to many things, it can be more difficult to avoid the allergens completely.

Dogs with complicated food allergies or with more allergies (for example, environmental allergies) may need medication—either long term just during allergy flare-ups. Of course, this doesn’t cure the allergy, but it minimizes the signs and makes your dog much more comfortable during those times. Allergy management is a team effort that can be very rewarding yet requires close collaboration between you and a veterinarian.

Can a Dog Suddenly Become Allergic to Their Food?

Partially, yes. Your dog may appear as if they have suddenly become allergic to a food they have been eating for months or years but, in fact, this process is gradual. That’s how food allergies in dogs develop. A dog eats the same food for years and, eventually, the overexposure sets off the immune system and allows enough time for antibodies to build up. The dog may exhibit minor signs at first, but these might not be noticeable. Often, pet owners don’t realize that their dog is experiencing food allergies until they notice chronic itching or chronic digestive issues.

If you notice any type of skin irritation, you should consult with your vet. Parasites and allergies are among the most common causes of skin issues in dogs. It doesn’t matter that your dog has been eating the same food for years and has been fine. In fact, that is how food allergies develop in the first place.

divider dog paws 4 oct 2024

Final Thoughts

Allergies can be problematic for any dog. However, once you learn to recognize the signs that your dog has food allergies, you can take action and work alongside a vet to identify and avoid the food ingredient(s) that are causing your dog’s problems. While food allergies cannot be cured, most of the time they can be managed quite successfully with the right diet. If you suspect that your dog might be allergic to something in their food, reach out to your vet. There are many options for feeding your dog to ensure they continue to enjoy an excellent quality of life without skin and digestive problems

See Also:


Featured Image Credit: Olena Yakobchuk, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

We Bred English Bulldogs So Extreme They Can’t Mate Naturally

Picture this: A male English Bulldog waddles over to a female in heat, full of confidence and swagger. Then… nothing. His barrel chest,...

Damning Dry Dog Food Report Not What It Seems

Over the past few days, pet and vet communities have been reeling from the revelation that high levels of heavy metals have been...

Ask Dr. Paola- Help! My Dog’s Won’t Stop Barking! (February 23, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

Why You Should Never Ignore Yellow Dog Poop

Yellow dog poop is one of those things that sounds bizarre until it happens to your dog. Then suddenly you’re standing there with...

More related

17 Pet Adoption Statistics & Facts to Know in 2026

Note: This article’s statistics come from third-party sources and do not represent the opinions of this website. When you’re thinking about getting a...

Little Dog, Big City – Gizmo Goes Urban

Welcome to the Wednesday Dogs of Dogster! Every Wednesday, we share a story from one of our Dogsters. This week is about Kate...

Can Dogs Eat Cream Cheese? Vet-Verified Facts & Health Tips

Whether it’s breakfast, lunch, or dinner, there’s a good chance your pup is hanging out by your side when you’re eating, and they’re...

Chow Pei (Shar Pei & Chow Chow Mix): Info, Pictures, Care & More

A hybrid between the Shar Pei and the Chow Chow, the Chow Pei is an independent and loyal dog that tends to exhibit...

Keep reading

Can Dogs Eat Frosted Flakes? Vet-Verified Facts & Nutrition Guide

While Frosted Flakes are a popular breakfast food for both children and adults, they’re not so great for dogs. Frosted Flakes don’t add any nutritional value to a dog’s diet, and the added sugar can lead to health complications if...

Can Dogs Eat Frosted Flakes

Can Dogs Eat Hibiscus? Vet Approved Facts & FAQ

When growing plants in our garden, many dog lovers aren’t aware of the possible toxicity our beautiful plants have which can harm our pets. Hibiscus is a type of perennial flowering plant that adds beauty to many gardens and is...

Can Dogs Eat Hibiscus

How Much Should a French Bulldog Eat? Vet Explained Puppy to Adult Feeding Guide

Getting a new puppy is always so exciting! You have this little bundle of fur just wanting to eat, sleep, and play with you. As a veterinarian, we often get asked how much food is appropriate to be feeding a...

french bulldog eating or drinking from a bowl

Lean Meats for Dogs in Fresh Food Diets: Vet Approved Facts, Pros, Cons & FAQ

Protein is an essential part of your dog’s diet, and can be found in meat, eggs, and certain vegetables. It plays a vital role in your dog’s body, such as building and sustaining muscles, tissues, and cells. Without protein, your...

fresh raw meat on old wooden table

Can Dogs Eat Spring Mix? Vet-Approved Facts & FAQ

Spring mix is typically a mixture of different greens, such as romaine lettuce, iceberg lettuce, bibb lettuce, spinach, arugula, and mustard greens. If you have a dog that eyeballs you longingly when you eat spring mix, you may wonder if...

Can Dogs Eat Spring Mix

Can Dogs Eat Teriyaki Sauce? Vet Reviewed Nutrition Facts & FAQ

Teriyaki sauce can spice up many of our meals. However, while it is tasty, it isn’t safe for our canines. Teriyaki sauce contains many ingredients and spices—some of which may be toxic to dogs. For instance, this sauce often includes...

Can Dogs Eat_teriyaki sauce

9 Best Grain-Free Dog Foods in Canada in 2026 – Reviews & Top Picks

Grain-free diets have been all the rage in the pet industry lately, but are they safe or even necessary? Most vets only recommend a grain-free diet for their pet if it has been proven that the pet in question does...

a dog eating on a bowl

Can Dogs Eat Apple Pie? Vet-Verified Nutrition Facts & Info

We can share a lot of our food items with our dogs, permitting we know the safety and nutritional quality. After all, our dogs are omnivorous just like us. However, when it comes to sweet treats and heavily processed goods,...

Dogster-Can-Dogs-Eat-Apple Pie

Love Dogs? So Do We! Join the Dogster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Dogster Email Newsletter