Hypoallergenic Dog Food: What It Is, Does It Really Work, and Why?


If your dog suffers from itchy skin, your veterinarian may have suggested a “diet trial” or “elimination diet” using hypoallergenic dog food as the most effective solution (1).

Many people are familiar with other products labeled “hypoallergenic,” such as cosmetics, but we rarely see foods labeled as such.

So what exactly is hypoallergenic dog food, and will it work for your dog?

How To Tell If Your Dog Has Food Allergies

First, before you dive into and just buy this dog food because it seems better.

Save yourself some time and money and don’t buy unless your certain your dog has a food allergy.

The signs and symptoms of food allergies looks like this:

  • Loose stools (watch for runny poop or diarrhea if it happens after eating a particular protein source)
  • Gastrointestinal issues like lots of gas
  • Itchy skin and rashes or hives
  • Lethargic looking
  • They tend to have frequent infections in their ears and on their skin
    • Look for lesions

Unfortunately, any of these symptoms can be caused by other ailments and health problems.

These are just signs, the only way to know for sure is an appointment with your vet.

They will perform a food allergy test to see what’s causing the symptoms.

What is hypoallergenic dog food?

It’s common today for pet food companies to release hypoallergenic dog food brands alongside their regular foods for dogs.

But not every hypoallergenic food will work for every dog or every canine health problem it may be bought for.

In the most basic sense, hypoallergenic dog food is easier for dogs to digest and absorb.

Regarding pet foods, the term “hypoallergenic” means that while the food may still contain potential allergens, their molecular structure is so small that the dog’s body can’t recognize them.

This is done by breaking down, or hydrolyzing, the proteins.

Hydrolyzed protein is a type of protein that’s broken down (hydrolyzed) into amino acids, which are very small.

Yet this type of protein still provides a complete array of essential amino acids the dog’s body requires.

This is done so that the bodies of dogs that have sensitive digestive systems don’t have to work as hard to break down their food (protein).

Food allergies in dogs are recognized and detected similarly in people, and research shows that people and dogs share many similar food allergies (2).

Which dog foods are really hypoallergenic?

The term “hypoallergenic” has no legal definition regarding pet foods.

Therefore, dog owners need to be aware when looking for an “allergy dog food diet,”.

Many dog food brands may have the word “hypoallergenic” on their packages but do not include hydrolyzed ingredients.

If food does not include the term “hydrolyzed” on the ingredients label or contains more than one protein source, it is not hypoallergenic.

Unfortunately, dog food labeling guidelines are not as strict as labeling requirements for human foods – Dr. Dana Brown has discussed this in the Understanding Dog Food article.

Due to loose pet food regulations, companies find loopholes to mislabel their products, and it’s still legal for them to do so.

For example, many bloggers have written that Orijen-brand dog foods are “hypoallergenic.”

This is not true – Orijen adult formula contains more than one protein source, all common allergens – eggs, poultry, and fish.

While Orijen dog food is a great brand, it won’t work for dogs with allergies.

That being said, there are a few more things that you need to know about hypoallergenic dog foods, how exactly they affect dogs and how to pick the right one for your pet.

With so many controversies in the pet food market, I’d like dog owners to stay informed.

Does Hypoallergenic Dog Food Work?

Does Hypoallergenic Dog Food Really Work

Why Do Hypoallergenic Dog Food Diets Exist?

Hypoallergenic diets were developed for dogs and cats with food allergies (3).

Pet food allergies cause a wide range of problems – from chronic itchy or infected skin to ear infections, GI tract problems, and more.

Food allergies in dogs are often caused by well-known ingredients that the pet has eaten before.

What is the number one food allergy in dogs?

Several studies show (4) that the most common type of foods that dogs are allergic to are from protein sources like beef, dairy products, eggs, soy, chicken, and wheat.

Further studies (5) show that dogs can be allergic to even more foods, with beef being on the lower scale:

Most common foods dogs are allergic to - study
Chart showing the most common foods dogs are allergic to. © The Korean Society of Veterinary Science

Why are dogs allergic to some foods?

By design, the immune system in both dogs and humans is supposed to protect the body from foreign invaders that can hurt it, such as viruses and bacteria.

Allergies in dogs happen when the canine body’s immune system overreacts to a harmless substance, falsely labeling it as an “invader.”

For reasons still not fully understood by science, in some individuals and canines, the immune system is overly sensitive and will react with “allergy symptoms” to certain otherwise harmless substances.

Some of these allergies can be genetically linked in dogs, while others may be due to previous exposure to a particular food item.

The reason most hypoallergenic dog foods alter their protein is that studies have shown that protein is what most dogs and cats are usually allergic to (6).

Typically, it’s difficult to pinpoint exactly what food item the dog may be allergic to.

This is why the elimination diet using hypoallergenic dog food may be the most effective method today, allowing the vets and owners to find the exact food allergen (7).

Are Hypoallergenic Dog Food Diets Effective?

Most of the time, hypoallergenic diets work.

While it’s not a sure-proof way or the fastest way to understand what foods the dog may be allergic to, some studies have shown that currently, an elimination diet with hypoallergenic dog foods and gastroscopic food sensitivity testing (GFST) is the best approach we have (8, 9, 10).

Hypoallergenic dog food is especially good for allergic dogs that do not respond to other therapeutic dog food diets; however, that’s not always the case.

Dogs and cats that benefit most from hypoallergenic dog food typically suffer from the following:

  • Food allergies
  • Atopic Dermatitis (10% of dogs with atopic dermatitis will have food allergy)
  • Irritable Bowel Disease (IBD)
  • Lymphangiectasia

Owners must know that switching their dog or cat to a hypoallergenic dog food diet will not change their condition overnight.

Studies have analyzed (11) the length of using hypoallergenic dog food and found that while three weeks are sometimes enough, keeping the dog on a diet for at least ten weeks is usually recommended.

Furthermore, other issues contributing to your pet’s allergic discomfort, such as an active skin infection, must be addressed before a complete diet change (5).

What Are Good Hypoallergenic Dog Foods?

Most hypoallergenic or hydrolyzed dog food diets available are prescription veterinary diets; however, there are some common over-the-counter hypoallergenic dog foods that pet owners choose.

Talk to your veterinarian about which diet is best for your pet.

Also, I recommend reading this article about prescription dog food.

It closely looks at how companies sometimes dishonestly overprice their pet foods.

You don’t always need the most expensive hypoallergenic dog food to fix your pet’s allergy problems.

The most popular hypoallergenic dog food diets are these four:

Again, before picking any hypoallergenic dog food for your canine, discuss it with your veterinarian.

Come up with a feeding plan first.

What to Expect When Switching to Allergy Diets

Your veterinarian will give specific instructions for switching your dog’s old diet to his new hypoallergenic feeding regime.

Typically, the switch is made very gradually.

This will help prevent any digestive upset for your dog.

Here are a few tips to keep in mind when switching to hypoallergenic dog foods:

1. Purchase new water and dog food bowl for your pet (as the above studies show, old dishes, especially plastic bowls, can hold allergens even if cleaned in a dishwasher).

2. Transition your dog slowly. Mix his old dog food with his new hypoallergenic dog foods for 3-4 days, then feed only the hypoallergenic diet.

3. Do not give your dog any doggy treats, no bully sticks or bones, no chews, or anything else that could contain non-hypoallergenic ingredients.

4. Do not give your dog any people food for the very same reason.

5. As the above study indicates, it’s best to feed your dog the hypoallergenic dog food diet exclusively for at least 6-8 weeks and possibly even ten weeks.

After the “diet trial” period of 6-10 weeks, many dog owners will know whether the new hypoallergenic dog food works.

You must consult your vet about signs you may or may not see in your pet, potentially pointing to allergens.

Sometimes, your dog can be returned to the regular high-quality commercial kibble if you avoid certain ingredients. Other times, you may need to incorporate homemade dog foods.

Occasionally, if the hypoallergenic dog food diet is the only thing that works for your canine, it may need to be a life-long change to avoid any issues.

Why Are Hypoallergenic Dog Food Diets So Expensive?

What are the Alternatives to Hypoallergenic Diets?It’s true that when switching to hypoallergenic dog food, you’ll probably have to increase your pet feeding budget.

The most common explanation for this expense increase is that these diets take years, if not decades, to develop and test.

Processing hypoallergenic dog food costs more than manufacturing regular dog food.

For example, Hill’s Science Diet reports that its hypoallergenic food, z/d Ultra, is produced exclusively on its production line in a separate facility from the rest of its food processing where its other dog food brands are made.

They explain that this eliminates the cross-contamination of allergens from other production lines.

The separate equipment, maintenance, and personnel add to the overall cost.

Another example – is Royal Canin. They use controlled manufacturing practices and a DNA test for each batch of Anallergenic food to ensure no “foreign” protein contamination.

The more precautions a pet food company takes to ensure good quality control and ensure the food is hypoallergenic, the more expensive it will be.

What are the Alternatives to Hypoallergenic Diets?

As the above research indicates, an elimination diet using hypoallergenic dog food is the most common way to deal with allergies in dogs.

But there’s an alternative.

For canines with food allergies, veterinarians use one of two types of diets when addressing allergies.

The first is the hypoallergenic diet, and the other is the novel protein/carbohydrate diet.

These novel protein/carb diets introduce a single protein source and a single carbohydrate source into the dog’s diet.

Ideally, the protein and carbohydrates should be the ones the dog has never been exposed to.

These diets most commonly include wild meats or fish, such as venison, salmon, lamb, or duck (6).

The carbohydrate sources can consist of vegetables like sweet potatoes or peas.

Novel protein slash carbohydrate diets for dogs are introduced, like the hypoallergenic dog food diet I’ve outlined above.

They are often slightly less expensive than hypoallergenic diets but still require veterinary prescriptions.

If your veterinarian recommends a novel protein/carb diet, cooking at home for your pet may be possible using appropriate homemade dog food recipes that will work for your dog.

If home-cooking interests you, ask your vet for a referral to a canine nutritionist. The nutritionist can formulate a formula specifically for your pet’s needs.


What breed of dogs are allergic to chicken?

Chicken is a common food allergy for all breeds.

But the breeds that are particularly vulnerable are: Golden Retrievers, Labradors, Dalmatians, Boxers, Boston Terriers, German Shepherds, and Cocker Spaniels.

How long does it take for a food allergy to clear up in dogs?

Unfortunately, when dogs have food allergies, symptoms can persist despite having switched your dog’s food. Expect symptoms to stick around for eight weeks or so before being completely gone.

Is hypoallergenic the same as grain free?

No. Not all grain-free dog food is hypoallergenic.

And the same goes for the opposite. Not all hypoallergenic dog food is grain free.

Hypoallergenic Dog Food: Summary

Does Hypoallergenic Dog Food Really WorkWhen your dog has an allergy, the first thing to do is speak with your veterinarian and formulate a plan of action.

As discussed above, an elimination diet using either hypoallergenic dog food or a novel protein/carb diet is the best way toward success.

However, studies have shown (12, 13) that including an increased amount of omega-3s in your dog’s diet may help with allergies and improve many other health factors (14).

The best way to add omega-3s into the dog’s diet is to give fish oil supplements.

Another thing to consider is probiotics for dogs.

There is no evidence (15) as to how effective probiotics are for dogs with allergies (yet good for their general health), but there are a lot of studies on positive effects for people with allergies (16, 17).

As established above, dogs and humans have much in common when dealing with allergies.

Find a way to add any of these to your dog’s diet, whether through supplementation or some fish oil and probiotics, into your dog’s food.

However, discuss this with your vet beforehand to track the elimination diet successfully.


Click here to see study citations and references

Footnotes, study citations, and further reading:


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