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 that are labelled “hypoallergenic”, such as cosmetics, but we rarely see foods labelled as such. So what exactly is hypoallergenic dog food, and does will it work for your dog?

What is hypoallergenic dog food?

It's common today for pet food companies to release a type of hypoallergenic dog food brands to go alongside their line of 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.

When it comes to 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 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 in a similar way they are in people, and research shows that people and dogs share many of similar food allergies (2).

Which dog foods are really hypoallergenic?

The term “hypoallergenic” has no legal definition when it comes to pet foods.

Therefore, dog owners need to be aware when looking for an “allergy dog food diet,” as many dog food brands may have a word “hypoallergenic” on their package, but not include hydrolyzed ingredients. If food does not include the term “hydrolyzed” on the ingredients label, or if it contains more than one protein source, then it is not hypoallergenic.

Unfortunately, dog food labeling guidelines are not as strict as labeling requirements for human foods – Dr. Dana Brown has talked about this in 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, I've seen many bloggers write 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 itself 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 pet food market, I'd like for dog owners to stay informed.

RELATED: 7 Tips On How To Feed Dogs To Deal With and Prevent Allergies

Does Hypoallergenic Dog Food Work?
(and what else pet owners must know)

Does Hypoallergenic Dog Food Really Work

Why Do Hypoallergenic Dog Food Diets Exist?

Hypoallergenic diets were developed for dogs and cats that suffer from food allergies (3).

Food allergies in pets cause a wide range of problems – from chronic itchy or infected skin, to ear infections, to GI tract problems and more. Food allergies in dogs are most often caused by well-known ingredients that the pet has eaten before.

Several studies show (4) that the most common type of foods that dogs are allergic to are beef, dairy products, 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 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 substance that is harmless, falsely labeling it as an “invader.”

For reasons that are still not fully understood by science, in some individuals and canines, the immune system is overly sensitive, and it 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 certain food item.

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

Typically, it's very 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 we have 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 most fastest way to understand what foods the dog may be allergic to, some studies have shown that currently 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 very allergic dogs that do not respond to other types of therapeutic dog food diets; however, that's not always the case.

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

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

Owners need to be aware that simply switching your 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 3 weeks are sometimes enough, it's usually recommended to keep the dog on the diet for at least 10 weeks.

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

ASK A VET: How to Put an Overweight Dog on a Diet?

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 be best for your pet.

Also, I recommend reading this article about prescription dog food which takes a close look 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.

Most popular hypoallergenic dog food diets are these five:Royal Canin HP (Hydrolyzed Protein)

  1. Royal Canin HP (Hydrolyzed Protein)
  2. Royal Canin Hypoallergenic
  3. Hill’s Science Diet z/d Ultra
  4. Purina HA Hydrolyzed

Again, before picking any type of hypoallergenic dog food for your canine, discuss it with your veterinarian. You need to 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 onto 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 above studies show, old dishes, especially plastic bowls, can hold allergens even if cleaned in a dishwasher).

2. Transition your dog slowly. Start by mixing his old dog food with his new hypoallergenic dog foods for 3-4 days, and 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 10 weeks.

After the “diet trial” period of 6-10 weeks, many dog owners will know if the new hypoallergenic dog food really works or not. You will need to consult with your vet about signs you may or may not be seeing in your pet, which will potentially point at allergens.

Sometimes, your dog can be returned onto the regular high quality commercial kibble as long as 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.

RELATED: 31 Dog Food and Feeding Myths You Need to Stop Believing

Why Are Hypoallergenic Dog Food Diets So Expensive?

What are the Alternatives to Hypoallergenic Diets?It's true that when switching to a 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.

The processing that the hypoallergenic dog food requires 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 very own production line in a separate facility from the rest of its food processing where their other dog food brands are made.

They explain that this eliminates cross-contamination of allergens from other production lines. The separate equipment, maintenance and personnel add onto the overall cost.

Another example – Royal Canin. They use both controlled manufacturing practices and a DNA test for each batch of Anallergenic food to ensure that there is no “foreign” protein contamination. The more precautions that a pet food company takes to ensure good quality control and to ensure the food is hypoallergenic, the more expensive it will be.

What are the Alternatives to Hypoallergenic Diets?


As the above research indicates, 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 what is called 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 carbohydrate should be the ones that the dog has never been exposed to before. Many of these diets most commonly include wild meats or fish, such as venison, salmon, lamb or duck (6). The carbohydrate sources can include vegetables like sweet potatoes or peas.

Novel protein slash carbohydrate diets for dogs are introduced in the same manner as a hypoallergenic dog food diet I've outlined above. Often they are slightly less expensive than hypoallergenic diets, but they still require veterinary prescriptions.

If your veterinarian recommends a novel protein/carb diet, it may be possible to cook at home for your pet using appropriate homemade dog food recipes that will work for your dog. If home-cooking interests you, definitely ask your vet for a referral to a canine nutritionist. The nutritionist can formulate a recipe specifically for your pet’s needs.

What else can I do?

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, elimination diet using either hypoallergenic dog food or 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 as well as improve a tons of other health factors (14). The best way to add omega-3s into the dog's diet is give dog fish oil supplements.

Another thing to consider are 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's a lot of studies on positive effects for people with allergies (16, 17). As established above, dogs and humans have a lot in common when it comes to dealing with allergies.

Find a way to add any of these into your dog's diet, whether through supplementation or by adding some fish oil and probiotics into your dog's food. However, discuss this with your vet beforehand so that you can successfully track the elimination diet.

READ NEXT: 8 Resources for Most Common Dog Allergies


Click here to see study citations and references

Footnotes, study citations and further reading:

  1. Verlinden A1, Hesta M, Millet S, Janssens GP. Food allergy in dogs and cats: a review. Crit Rev Food Sci Nutr. 2006;46(3):259-73.
  2. Buchanan BB1, Frick OL. The dog as a model for food allergy. Ann N Y Acad Sci. 2002 May;964:173-83.
  3. Ermel RW1, Kock M, Griffey SM, Reinhart GA, Frick OL. The atopic dog: a model for food allergy. Lab Anim Sci. 1997 Feb;47(1):40-9.
  4. Mueller, R. S., Olivry, T., & Prélaud, P. (2016). Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats. BMC Veterinary Research, 12, 9.
  5. Kang, M.-H., Kim, H.-J., Jang, H.-J., & Park, H.-M. (2014). Sensitization rates of causative allergens for dogs with atopic dermatitis: detection of canine allergen-specific IgE. Journal of Veterinary Science, 15(4), 545–550.
  6. Wills J1, Harvey R. Diagnosis and management of food allergy and intolerance in dogs and cats. Aust Vet J. 1994 Oct;71(10):322-6.
  7. Jeffers JG1, Meyer EK, Sosis EJ. Responses of dogs with food allergies to single-ingredient dietary provocation. J Am Vet Med Assoc. 1996 Aug 1;209(3):608-11.
  8. Marks SL1, Laflamme DP, McAloose D. Dietary trial using a commercial hypoallergenic diet containing hydrolyzed protein for dogs with inflammatory bowel disease. Vet Ther. 2002 Summer;3(2):109-18.
  9. Guilford WG1, Strombeck DR, Rogers Q, Frick OL, Lawoko C. Development of gastroscopic food sensitivity testing in dogs. J Vet Intern Med. 1994 Nov-Dec;8(6):414-22.
  10. Elwood, C. M., Rutgers, H. C. and Batt, R. M. (1994), Gastroscopic food sensitivity testing in 17 dogs. Journal of Small Animal Practice, 35: 199–203. doi:10.1111/j.1748-5827.1994.tb01689.x
  11. Rosser EJ Jr1. Diagnosis of food allergy in dogs. J Am Vet Med Assoc. 1993 Jul 15;203(2):259-62.
  12. Scott DW1, Miller WH Jr. Nonsteroidal anti-inflammatory agents in the management of canine allergic pruritus. J S Afr Vet Assoc. 1993 Mar;64(1):52-6.
  13. Olivry, T., DeBoer, D. J., Favrot, C., Jackson, H. A., Mueller, R. S., Nuttall, T., … for the International Committee on Allergic Diseases of Animals. (2015). Treatment of canine atopic dermatitis: 2015 updated guidelines from the International Committee on Allergic Diseases of Animals (ICADA). BMC Veterinary Research, 11, 210.
  14. Mooney MA1, Vaughn DM, Reinhart GA, Powers RD, Wright JC, Hoffman CE, Swaim SF, Baker HJ. Evaluation of the effects of omega-3 fatty acid-containing diets on the inflammatory stage of wound healing in dogs. Am J Vet Res. 1998 Jul;59(7):859-63.
  15. Kelley RL1, Minikhiem D, Kiely B, O'Mahony L, O'Sullivan D, Boileau T, Park JS. Clinical benefits of probiotic canine-derived Bifidobacterium animalis strain AHC7 in dogs with acute idiopathic diarrhea. Vet Ther. 2009 Fall;10(3):121-30.
  16. Furrie E1. Probiotics and allergy. Proc Nutr Soc. 2005 Nov;64(4):465-9.
  17. Vanderhoof JA1. Probiotics in allergy management. J Pediatr Gastroenterol Nutr. 2008 Nov;47 Suppl 2:S38-40. doi: 10.1097/01.mpg.0000338810.74933.c1.