7 Best Hydrolyzed Protein Cat Foods – Wet and Dry Reviews

What is hydrolyzed protein?

To get a clear understanding, you should know that amino acids are the essential protein building blocks and peptides with the latter having a shorter amino acid chain, usually, (2-50). Both peptides and proteins are linked together via a peptide or amide bond.

Therefore, protein hydrolysis is the chemical breakdown of proteins into smaller peptide units or segments (partial hydrolysis) or individual isolated amino acids (full hydrolysis). These occur via breaking the peptide bonds that hold them together.

The process can use chemicals or enzymes. While the use of chemicals is more efficient (achieves a higher level of hydrolysis), it may degrade some amino acids present, reducing the value of the particular foods. On the other hand, an enzymatic process will preserve vital compounds since it doesn’t involve high temperatures or pressure.

Why hydrolyzed cat foods?

Cats and dogs can suffer from food allergies or intolerance at any age. However, cases tend to be higher as they age.

While these two terms are often used synonymous, food intolerance (non-allergic), occurs when your feline finds it hard to digest some foods, thus presenting some symptoms.

On the other hand, allergies are reactions that occur when their body falsely or mistakably confuses some dietary components as antigens or allergens, yet they are not necessarily toxins, harmful, or pathogens such as those cause food poisoning.

Antigens are foreign bodies or toxins that trigger an immune response or allergic reactions commonly via the production of antibodies. On the other hand,  allergens are a special kind of antigens that trigger the IgE antibody response.

Some of the common food allergens include beef, dairy, and fish, accounting for a more significant percentage of cases. However, chicken, lamb, eggs, corn, and wheat may trigger them.

Since proteins and glycoproteins constitute a significant cause of allergies, the primary objective of protein hydrolysis is to breakdown protein into smaller units that any present antigens or allergens will recognize as a threat.   

For instance, the resulting fragments (peptide units) should be small enough to ensure they don’t cross-like with two IgE antibodies, usually attached to the mast cell surface. Otherwise, degranulation and allergic reaction symptoms (IgE-mediated ones) will occur.

Therefore, protein hydrolyzed feline foods are hypoallergenic diets designed to help reduce or manage allergies while offering other benefits.

For instance, a hydrolyzed beef diet will not trigger allergic reactions as intact beef, i.e., the mast cells (white cells involved in immunity response), not initiate a degranulation that will cause an allergic reaction as they would in intact beef. 

At a glance: Top 3 best hydrolyzed foods for cats

Rank Brand Rating  
Best Overall Royal Canin Hydrolyzed Protein Adult HP Dry Cat Food 4.7 Check Price
Runner’s Up Hill’s Prescription Diet z/d Feline Dry Cat Food 4.5 Check Price
Best Treats Hill’s Prescription Diet Hypo Treats Feline 4.6 Check Price

Benefits of hydrolyzed protein cat foods and cons

Some of the benefits that these foods present include the following:

  • Kitties can still eat favorite protein– Your pet can eat their favorite food without resulting in hypersensitivities since these foods have only hydrolyzed proteins. Therefore, they make it easy to provide complete and balanced diets without the hustle of homemade meals.
  • Digestibility – Besides reducing allergenicity and antigenicity, the breakdown improves digestibility, something recommended in hypoallergenic foods.
  • Most are single protein sources – Since manufacturers use one hydrolyzed protein sources, this further minimizes the chance of hypersensitivities.
  • Lower allergies – research has shown smaller instances of hypersensitivities in cats and dogs. Furthermore, since these diets are truly hypoallergenic, they will reduce the possibilities of new allergies if fed on a long-term basis.
  • May Help felines IBD and acute enteritis – Most felines with inflammatory bowel disease (IBD) and acute enteritis are likely to benefit from these diets.


  • Reduced palatability and increased osmolarity –  The disruption of protein disruption lowers palatability and the smaller the peptides, the bitter-tasting they tend to be.  On the other hand, high intestinal osmolarity will draw more water to the intestines, resulting in diarrhea.
  • Don’t heal sensitivities – While their body will not detect allergens, the sensitivity will still exist and occur if you change the food.
  • Most foods have soy – while experts recommend protein-based foods, some most hydrolyzed diets have soy (plant-based), which may be biologically not ideal for kitties.  However, hydrolyzed soy and corns lead to lead to lesser allergies than intact ones.
  • Unnatural amino acid conversion – While there isn’t sufficient evidence, some experts argue that methods and chemicals used in hydrolysis don’t convert proteins as it naturally occurs in the body. There is a possibility of long-term side effects.

Selecting the best hydrolyzed cat foods

Before you think of switching to any hypoallergenic diets, your vet should supervise an elimination trial to help pinpoint the possible cause.

When selecting the best hydrolyzed food or any other, some important consideration includes the following:

  • Look at the product label and name. These two should provide more information, including the intended life stage, manufacturer name, and address, guaranteed analysis, nutritional adequacy statement, ingredients, calorie statement, among other things. See details on how to choose the best cat food.
  • Ensure it has only hydrolyzed protein and not just soy, milk, or a few other ingredients.
  • Go for animal-based protein and fat sources as they are a source of energy. Additionally, fats help in the absorption of fat-soluble vitamins as well as provide omega-3 and omega-6 fatty acids.
  • Buy ones that have fewer carbs, limited in number, and those known to cause hypersensitivities hardly.
  • Ensure they don’t have artificial flavors, dyes, preservatives, or any other low-quality fillers and by-product meals.
  • They should have limited synthetic vitamins or minerals or none at all.
  • Complete and balanced with recommended AAFCO nutrition levels unless fed on supplemental, intermittent, or as a treat.
  • Even with the best brands, trial and error may help identify which ones work for your kitties.

Best hydrolyzed cat foods reviews – wet and dry

Once your vet has approved or recommended hydrolyzed diets, you need to decide on which brand to buy. Let us look at some of the best brands.

Note: A standard cup is 8 oz. and ingredients are always with the most abundant once first.

1. Royal Canin Hydrolyzed Protein Adult HP Dry Cat Food

This veterinary exclusive dry feline food is an excellent pick if your cat has sensitivities to food that result in symptoms including, GI upsets, skin, and coat issue.


  • Has hydrolyzed soy formulation that will ensure your pet’s immune response to protein doesn’t occur.
  • It is highly palatable and will support digestion as it has a blend of prebiotics and fiber, making it helpful for felines prone to diarrhea and other stomach upsets.
  • It effectively reinforces a skin barrier in your pet, thanks to the peak levels of amino acids and vitamin C that Royal Canin Hydrolyzed Protein Adult HP Dry Cat Food has
  • Has added omega-3 fatty acids DHA and EPA that will promote your pet’s coat and skin’s health.
  • Royal Canin has a stringent manufacturing process to curb cross-contamination that will make their food less hypoallergenic


  • Many experts are critical about the use of hydrolyzed soy, a plant-based protein instead of an animal-based source.

Additional information

  • Guaranteed analysis: Crude protein: 24.0% (min), crude fats: 18.0% (min), crude fiber: 6.3% (max), moisture: 8.0% (max) as it is basis.
  • First ingredients: Brewers rice, hydrolyzed soy protein, chicken fat, powdered cellulose, natural flavors, dried plain beet pulp.
  • Quantity and calories: Available in a 0.75lbs, 7.7lbs, and 17.6 lbs bags. Its calculated calories are 3909 kcal ME/kg or an equivalent of 328 kcal ME/cup.
Royal Canin Hydrolyzed Protein Adult HP Dry Cat Food

2. Hill’s Prescription Diet z/d Feline Dry Cat Food

Being cheaper, economical, and having many other benefits, you may prefer dry cat food. In such a case, Hill’s Prescription Diet z/d Feline is one such choice.

Key benefits

  • It is a work of experts meant to manage GI upsets, severe food reactions as well as manage food-related coat, ear conditions, or irritated skin.
  • The formulation uses a single source, hydrolyzed animal protein, as well as one carbohydrate source.
  • It has added antioxidants and doesn’t have soy protein, artificial flavors, colors, or lactose to minimize sensitivities.
  • Ideal for bladder health as it uses S+OXSHIELD™, which will reduce the formation of urinary crystals (struvite or calcium oxalate).
  • Supports immunity and creates a healthy skin barrier


  • Its first ingredient is brewer’s rice, meaning it is the most abundant in the diet.

Additional information

  • Guaranteed analysis: Protein: 34.5%, Fats: 15.2%, Carbohydrate (NFE0:40.7%, Fiber: 3.2% on dry matter basis.
  • First ingredients:  Brewers rice, hydrolyzed chicken liver, rice protein concentrate, powdered cellulose, soybean oil, and coconut oil.
  • Quantity and calories: 4 lb or 8.5 lb bags and has 3688 kcal/kg or 408kcal per cup.
Hill’s Prescription Diet z/d Feline Dry Cat Food

3. Hill’s Prescription Diet z/d™ Feline Wet Cat Food

If your cat is sensitive or intolerance to food, i.e., has GI upsets, gets an allergic reaction from some protein sources, or gets skin and ear irritation, Diet z/d™ Feline Wet Cat Food is a good bet.

Key benefits 

  • This diet, a collaborative work of veterinarians and nutritionists, will manage food sensitivities and do away with skin sensitivities emanating related to foods.
  • It has highly hydrolyzed proteins, a single carb source (rice), essential fatty acids, and vital antioxidants.
  • Boosts digestion and ensures the right stool.  
  • Will keep a healthy skin barrier
  • Minimize chances of urinary stones (calcium oxalates and struvite crystals), thanks to the S+OXSHIELDTM technology.


  • It’s costly and has higher amounts of carbohydrates, yet these pets are strict carnivores.

Additional information

  • Guaranteed analysis:  Protein: 34.3%, Fats: 17.7%, Carbohydrate (NFE0:40.6%, Fiber: 1.6%, Ash: 5.8% on dry matter basis.
  • First ingredients: Hydrolyzed chicken liver, water, corn starch, powdered cellulose, and soybean oil
  • Quantity and packing: 24 cans of 5.5 oz. (156g) cans. Each can have 174 calories.
Hill’s Prescription Diet zd™ Feline Wet Cat Food

4. Purina Pro Plan Veterinary Diets HA Hydrolyzed Feline Formula Dry

Collaborative work of Purina researchers, veterinarians, and nutritionists is the brainchild of this diet designed to felines with food allergies or intolerances as well as conditions such as pancreatitis and inflammatory bowel disease.

Key benefits

  • Tastes great and is highly digestible to boost absorption.
  • Formulated with a single carbs source that doesn’t often cause allergies as well as other high-quality ingredients
  • The (MCTs) Medium Chain Triglycerides fatty acids present require little during absorption, storage, or use.
  • The St/Ox Defense supports urinary health by preventing calcium oxalate crystals and struvite ones.
  • Added antioxidants.

Additional information

  • Guaranteed analysis: Crude protein: 29.5% (min), crude fats: 9.0% (min), crude fiber: 4% (max), moisture: 10.0% (max), ash: 7.75% (max) as it is basis.
  • First ingredients: Rice starch, hydrolyzed soy protein isolate, partially hydrogenated canola oil preserved with TBHQ, and hydrolyzed chicken liver.
  • Quantity and calories:  4 lbs. and 8 lbs. bag with 3782 kcal/kg or 323 kcal/cup
Purina Pro Plan Veterinary Diets HA Hydrolyzed Feline Formula Dry

5. Blue Buffalo Natural Veterinary Diet HF Hydrolyzed for Food Intolerance Dry Cat Food

Does your feline have food sensitivities? Blue Buffalo HF Hydrolyzed for Food Intolerance has a formulation to help minimize hypersensitivities to common proteins. Why?

Key benefits

  • It has highly digestible salmon hydrolase produced via hydrolysis using enzymes and processed and dried at low temperatures.
  • It doesn’t have poultry or chicken by-products
  • Its grain-free, i.e., doesn’t have soy, corn, or wheat and has zero artificial preservatives or flavors.
  • The added fish oil and flaxseed are excellent natural sources of omega-3 fatty acids that will improve your cat’s skin and coat
  • Finally, the food has added vitamins E and C, kelp, and pumpkins (rich in antioxidants) to boost the immunity of your feline pal.


  • Its second to fourth ingredients are all plant-based, and its carbohydrates are slightly higher.

Additional information

  • Guaranteed analysis:Crude protein: 30.0% (min), crude fats: 14.0% (min), crude fiber: 4.0% (max), moisture: 9.0% (max) as it is basis.
  • First ingredients: Salmon hydrolysate, peas, potatoes, pea starch, canola oil, and pea protein.
  • Quantity and calories:  7 lbs. bag and 3,717 Kcals/kg or 430 Kcals/cup
Blue Buffalo Natural Veterinary Diet HF Hydrolyzed for Food Intolerance Dry Cat Food

6. Ultamino Dry Cat Food

This complete and balanced adult feline diet supports digestion while minimizing on food-related hypersensitivities.


  • Highly palatable and digestible
  • Its fiber blends will minimize GI upsets as they support efficient digestion.
  • Incorporates Relative supersaturation (RSS) that is good in reducing the formation of bladder stones, calcium oxalate crystals, and struvite.
  • Royal Canin observes a strict manufacturing procedure to prevent cross-contamination
  • Has DHA and EPA omega-3 fatty acids for healthy skin and coat and vitamin B and amino acids for reinforcing a skin barrier that minimizes irritations and sensitivities.


  • Costly compared to others of the same amount.
  • The minimum protein of 24.5% (on dry matter basis) is a little lower since AAFCO recommends at least 26%.

Additional information

  • Guaranteed analysis: Crude protein: 22.6% (min), crude fats: 15.0% (min), crude fiber: 5.7% (max), moisture: 8.0% (max) as it is basis.
  • First ingredients: Corn starch, hydrolyzed poultry by-products aggregate, coconut oil, vegetable oil, powdered cellulose, natural flavors, and dried chicory root
  • Quantity and calories: It comes in a 5.5-lb, and 1 kg has 3759 kcal ME (calculated) while a cup has 335 kcal ME
Royal Canin Veterinary Diet Feline Ultamino Dry Cat Food
Royal Canin Veterinary Diet Feline Ultamino Dry Cat Food

7. BLUE Natural Veterinary Diet HF Hydrolyzed for Food Intolerance Wet Cat Food

If your felines prefer wet food, BLUE Natural Veterinary Diet HF Hydrolyzed for Food Intolerance Wet Cat Food has the same benefits and qualities as its dry counterpart when it comes to food sensitivities and related symptoms.

Key benefits

  • Has readily digestible salmon hydrolase processed under low temperature and using enzymes to ensure the process is as natural as possible.
  • It doesn’t have grains, soy, corn, wheat, artificial flavors, or colors, as well as chicken or poultry by-products.
  • It has added natural sources of omega-3 fatty acids for good coat quality and skin.
  • It will boost your feline’s immunity since it is antioxidant-rich, including vitamin C and E.


  • Its crude fiber content is a little higher if calculated on a dry matter basis, i.e., it is about 13.6%.

Additional information

  • Guaranteed analysis:Crude protein: 8.0% (min), crude fats: 2.0% (min), crude fiber: 3.0% (max), moisture: 78.0% (max) as it is basis.
  • First ingredients: Salmon hydrolysate, water, potato starch, natural flavor, pea fiber, and agar-agar.
  • Quantity and calories: It comes in a box of 24 cans, each 5.5 oz. Each can’s calorific value is 161 Kcals.
7. BLUE Natural Veterinary Diet HF Hydrolyzed for Food Intolerance Wet Cat Food

Best hydrolyzed cat treats

Felines with food hypersensitivities require hypoallergenic treats, one of them being the hydrolyzed ones. Best brands to buy include:

1. Hill’s Prescription Diet Hypo Treats Feline

Instead of avoiding treats just because your cats have food sensitivities, you can buy Hill’s Prescription Diet Hypo Treats Feline as they will prevent adverse reactions caused by treats or foods.

Key benefits

  • These veterinary and nutritionists developed treats will prevent food sensitivity and promote urinary health (reduces calcium oxalate crystals and struvite formation).
  • They have added omega-3 and omega-6 fatty acids beneficial for skin and coat health.
  • Supports skin barrier function as they have added potent antioxidants.

Additional information

  • Guaranteed analysis:  Protein: 26.6%, Fats: 18.4%, Carbohydrate (NFE0:45.5%, crude fiber: 3.8 %, Ash: 5.8% on dry matter basis.
  • First ingredients: Hydrolyzed chicken liver, brewer’s rice, corn starch, soybean oil, powdered cellulose, and chicken liver flavor
  • Quantity and calories: Come in 2.5 oz., with a calorific value of 37.52kcal/kg or 2.3kcal per treat.
Hill’s Prescription Diet Hypo Treats Feline

2. Royal Canin Hydrolyzed Protein Feline Treats – adult

Buying the Royal Canin Hydrolyzed Protein Feline Treats gives your cat a chance to enjoy every bite without the worry or severe food hypersensitivity response that may cause GI and skin symptoms.

Key benefits

  • These treats for adult felines will minimize or avoid skin and GI sensitivities present in many proteins since hydrolysis breaks proteins to smaller peptide units that a cat’s immune response will not detect.
  • Have ideal amino acids, and vitamin B levels will provide skin barrier reinforcement, minimize skin sensitivities and irritation while offering nourishment needed for healthy skin.
  • Are highly palatable and digestible
  • Suitable for elimination trial or long term use.

Additional information

  • Guaranteed analysis:Crude protein: 23% (min), crude fats: 18% (min), crude fiber: 5.8% (max), moisture: 8.0% (max) as it is basis.
  • First ingredients: Brewer’s rice, hydrolyzed soy protein, chicken fat, powdered cellulose, natural flavors, vegetable oil, and dried plain beet pulp
  • Quantity and calories: Come in a 7.7 oz., package, and have a calorie value of 3919 kcal ME per kg or 1.6 kcal ME per treat.
Royal Canin Hydrolyzed Protein Feline Treats – adult

Signs of food allergies include

  • GI signs –They include diarrhea, vomiting, flatulence, noisy sounds from the GI tract, among others.
  • Pruritus signs – They include itchiness, biting, and scratching of ears, face, armpit, groin, belly, rectum (may cause scooting), paws, and so on.
  • Dermatological signs – Your felines may suffer from red, inflamed skin, scaling, recurrent skin and ear infections, hair loss, poor coat quality, and so on, some of which have a connection to itchiness.
  • Coughing, sneezing or wheezing

Other ways to manage feline food allergies

Alternative ways of managing allergies include buying some of the best brands of novel proteins as well as other hypoallergenic diets, which may have limited ingredients and a single protein source.

Novel protein feline diets use quail, ostrich, beaver, rabbit, pheasant, bison, venison, elk, kangaroo, duck, goat, duck, and beaver as their protein sources.

Finally, while homemade diets may help, they are prone to imbalances, and most people find the guidelines challenging.

See also


We are passionate pet and animal enthusiasts bringing insightful information to ensure your furry, flying or finned friends are happy and in good health. Feed them well and love them always.

  1. I was hoping to get some good information on this page. Unfortunately that was not the case. Cats are obligate carnivores. And yet the majority of the foods you recommend are dry so no real meat or moisture for them and their organs. And to make matters worse the dry food you are pushing has fillers like corn and rice which just contribute to obesity in cats. Not to mention by-products or chicken, which is often the cause of the allergy. I guess I have to keep looking.

    • Sorry, you couldn’t get the food you wanted. Presently, not many companies have hydrolyzed cat foods and what we gave you is what is available in the market. If your kitty doesn’t have allergies, why not switch to freeze-dried cat foods?

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