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Protein Allergy in Dogs: What Every New Dog Parent Must Know

Protein Allergy in Dogs: What Every New Dog Parent Must Know

If your pup experiences repeated cases of ear infections, itching, diarrhea, vomiting, sneezing, hair loss, hives, facial swelling etc, he may be suffering from food allergies.

And in most cases, the culprit is the proteins you are feeding him.

Dogs develop allergic reactions to foods or food ingredients that they have been exposed to for a long time (which is why feeding your dog one protein source month after month can lead to problems).

To avoid feeding your dog proteins that can trigger allergic reactions, you need to understand a few basics about protein allergy in dogs.

Fortunately, that’s exactly what this post intends to cover.

We’ll explore what protein allergy is, common protein allergens, how to tell if your dog has protein allergy, and whether or not it is a condition that can be cured.

Without further ado, let’s dive right in…

What Is Protein Allergy?

Protein allergy occurs when the dog’s immune system misidentifies a protein source as an invader instead of a food item and launches an adverse immune response.

In particular, the immune system produces antibodies to the protein source.

As a result, the dog’s body cells release histamines and other compounds that lead to itching, inflamed skin, and other allergic symptoms like diarrhea, vomiting, facial swelling, sneezing, hives, runny eyes, and excessive licking among many others.

Some unlucky dogs may also experience more subtle changes like weight loss, lack of energy, hyperactivity, and even aggression.

However, it is important to note that protein allergy is not the only cause of the mentioned symptoms.

Itching, skin infections, gastrointestinal (GI) upset, excessive licking etc can also be caused by fleas and environmental factors like pollen, dust mites, and grasses.

Protein Allergy vs. Intolerance

While the symptoms of protein allergy may look pretty similar to signs of protein intolerance, the two conditions are different.

Protein intolerance refers to a situation where a dog’s system has difficulties in digesting a protein source.

For instance, a dog is said to be lactose-intolerant if his system cannot process lactose in dairy products well (i.e the system is either missing or have low levels of lactase, the milk digesting enzyme), leading to diarrhea, vomiting, and a host of other GI issues.

On the other hand, protein allergy triggers an immune response. In other words, protein allergy occurs when a dog’s immune system is attacking a protein source.

Considering that food allergy occurs when a dog’s system produces antibodies against a food item, protein allergy tends to manifest after prolonged exposure to a type of protein.

So, protein allergy is usually triggered after your canine companion has consumed a certain type of protein before since it is the previous exposure that triggers an allergic reaction.

Conversely, protein intolerance happens the first time—and every time—your pup samples food containing a particular protein source because his body cannot digest it well.

Proteins Sources That Are Likely To Cause Allergies in Dogs

Generally, the number of dogs that are likely to have protein allergies is low.

However, there are some protein sources that are associated with more allergy cases than others.

Before we list them, it is important to note that there is nothing special about these protein sources other than the fact that they are some of the most common proteins in dog foods since time immemorial—which simply means one thing: dogs have been exposed to them a lot.

1. Beef

According to BMC Veterinary Research, beef constitutes about 34% of food allergies in dogs.

Feeding your dog beef for years can, therefore, increase his potential to develop allergy or intolerance to it.

By and large, beef is one of the most common ingredients in dog foods and treats, which may be the reason why many dogs may be allergic to it.

2. Dairy Products

Another common protein allergen is dairy products.

Some dogs have difficulties digesting lactose, a component found in milk. 

So, as we highlighted in the Protein allergy vs. intolerance section, most cases involving dairy products are protein intolerance and not an allergy.

Unfortunately, lactose intolerance in dogs produces similar symptoms (vomiting, diarrhea, skin itchiness, etc) as allergy in dogs.

So, how can you tell that your pup is suffering from a dairy allergy or intolerance?

Well, the latter will always produce GI-related symptoms while the former may produce skin itchiness as well.

3. Chicken

Just like beef, many dogs may be allergic to chicken because it is a common protein.

Yes, your dog’s immune system may perceive that plain old chicken as an intrusive substance and react to it aggressively causing an allergic reaction.

The common symptom of allergies caused by chicken is skin reactions around the face and toes.

Related Post: My Dog Is Allergic To Chicken: What Can I Feed Him?

4. Soy

Although it is touted as an excellent protein source in many health blogs, feeding soy has been shown to cause a wide range of health issues in dogs besides allergies.

For instance, it is reported to cause health issues like growth problems, thyroid, reproductive issues, and liver diseases.

5. Lamb

For a long time, lamb was considered as an excellent protein source for dogs that manifested allergy symptoms with regular proteins like beef and chicken.

However, modern dogs have been exposed to lamb for long enough to develop allergies.

So, you shouldn’t be surprised if you notice that your dog is allergic to lamb.   

6. Eggs

Some dog’s systems may also react to proteins contained in the egg yolk, causing allergy symptoms.

If your pup is one of such dogs, you should avoid eggs or dog foods with eggs as one of the ingredients.

Speaking of eggs for dogs, here are some insightful posts that you may be interested in:

While a bigger percentage of the proteins we have listed above are from animals (with exception of soy), it is important to note that there are also proteins in grains and vegetables.

And dogs can be allergic to them as well.

Most importantly, you should remember that any food ingredient can cause allergies in dogs.

How Can You Tell That Your Dog Has Protein Allergy?

Unfortunately, it is not easy to tell whether or not a dog is allergic to a protein source.

While many websites list tons of tests that can be used to diagnose allergies in dogs (using hair, blood, saliva, etc), there is no scientific proof that the tests are accurate.

So, the most reliable way of telling whether your pup is allergic to a protein source remains the elimination trial method.

Elimination trial involves feeding your dog a different protein source than what he is used to—for at least 8-10 weeks.

Protein sources that are used for such a purpose are often called Novel Proteins.

Essentially, they are proteins that are completely new to the dog.

Since the dog’s body has never been exposed to such proteins, there is less likelihood of an adverse immune response.

Protein sources that most vets recommend nowadays for elimination diets are fish and potato, rabbit and pea, alligator and coconut, and venison and potato.

To get accurate results, you should strive to feed the dog a single source of protein (probably with a single source of carbohydrate) for the entire trial period.

Avoid any kind of flavor as they could have traces of different proteins in them.

You should also avoid giving the dog table scraps, human snacks, and supplements that are not related to the protein source you are using for the elimination trial.

And to be sure that your fur baby is allergic to a given protein, you have to feed him the original protein that you suspected to be an allergen.

If you notice the allergic symptoms we mentioned in the previous sections, it is a clear sign of an allergy.

(Most dog owners are skeptical to perform this kind of test because they are worried that their dogs can manifest allergy symptoms again.)   

A Word of Caution…

Beware of commercial limited ingredient diets when doing elimination trail because while they are often marketed as excellent alternatives to dogs with allergies, some don’t live up to the hype.

Some companies include other ingredients (vegetables, fruits, kelp, etc) that could interfere with the results that you get during the elimination trial period.

The best foods to use during the trial period are homemade diets or those prepared by a board-certified veterinary nutritionist.

We also recommend the use of hypoallergenic diets made with hydrolyzed proteins.

For starters, hydrolyzed proteins are proteins that have been broken down into smaller molecules that your dog’s immune system cannot recognize as potential allergens, eliminating the possibility of triggering an allergic reaction.

A good example is Royal Canin’s Hypoallergenic Dog Food. It is carefully formulated to take into account the nutritional needs of your canine companion during the elimination trial period.

The formulation also provides a long-term solution to help you manage your pup’s sensitivity to food.

Can Protein Allergy In Dogs Be Cured?

The short answer is No.

The only cure is avoidance—avoiding the protein sources that your pup is allergic to.

Nonetheless, severe cases of protein allergies may require medication.

As we have discussed above, novel and hydrolyzed proteins also come in handy in managing certain cases.

The former will give you an opportunity of identifying the probable allergens should your pup develop allergic reactions while the latter lowers the chance of the protein source being recognized as a potential allergen by the dog’s body.

Whether you opt for a novel or hydrolyzed protein, stick to it all the time and ensure that other family members and pet handlers know about your Fido’s condition.

If you haven’t been reading dog food labels and ingredient lists, this is the right time to start to ensure that your dog’s food is free of unfriendly protein sources or allergens.


Feeding your dog a novel protein doesn’t prevent allergy.

It only makes it likely that if your pup develops an allergic reaction, you can easily tell that the protein in question is the culprit instead of other common protein sources like chicken or beef.

On the same vein, changing dog food ingredients does not prevent protein allergy in dogs.

It only limits your choices when you are trying to pinpoint the culprit considering that you cannot use every protein source that your dog has ever consumed during the dietary elimination trial process.

Parting Thoughts

Dealing with protein allergies can be challenge, particularly for first time dog parents.

However, proper diagnosis can go a long way in helping you understand the root cause of the problem and preventing future occurrences.

We hope that this post has shed some light on the basics that every dog owner should know when it comes to protein allergies in dogs.

If your pup has protein allergies, take heart, use the tips discussed herein, and work closely with your vet until his situation improves.

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