강아지 IBD(염증성 장질환) 처방식 추천 TOP 5 — 단백 가수분해 비교 가이드

Top 5 Prescription Diets for Canine IBD — A Comparative Guide to Hydrolyzed Proteins

DigestiveTop PicksMeongsiljang Veterinary Advisory Board

Prescription diets for canine IBD are therapeutic foods designed to reduce intestinal immune responses in dogs with inflammatory bowel disease by using hydrolyzed proteins, which are broken down into smaller fragments.

What Are Prescription Diets for Canine IBD? Why Choose Hydrolyzed Proteins?

A beagle receiving a prescription diet at a veterinary clinic

Prescription diets for canine inflammatory bowel disease (IBD) are therapeutic foods designed to reduce excessive intestinal immune responses in affected dogs by hydrolyzing proteins into small peptides that are less likely to trigger an immune reaction. In cases of IBD characterized by chronic vomiting, diarrhea, loss of appetite, and weight loss, dietary proteins can act as antigens due to immune system dysregulation and interactions with gut microbiota, leading to recurrent inflammation. The key to hydrolysis is breaking down proteins into fragments too small for immune cells to recognize as antigens. However, since IBD is a diagnosis of exclusion—meaning other causes such as lymphangiectasia must first be ruled out—elimination diet trials, including those using hydrolyzed protein diets, serve as a standard procedure for both diagnosis and treatment.

Why Hydrolyzed Diets Are the First-Line Dietary Choice for IBD

Hydrolyzed diets are recommended as the first-line dietary choice for dogs with IBD because they reduce dietary antigens, which are the starting point of the immune response. - Reduced antigenicity: Proteins are broken down into small peptides that are less likely to trigger an immune response, lowering the chance that immune cells will recognize them as antigens. - Elimination diet principle: Antigenicity is reduced without introducing novel proteins with limited prior exposure, allowing you to confirm whether a food reaction exists through a dietary trial. - Reduced reaction (not complete avoidance): While reactions to ingredients like chicken or beef are minimized, some individuals may still experience flare-ups even when fed hydrolyzed versions of the same ingredients, so complete avoidance is not guaranteed. According to veterinary nutrition literature, a significant number of dogs with chronic enteropathy achieve remission in response to hydrolyzed or elimination diets; however, moderate to severe cases typically require concurrent use of immunomodulators such as glucocorticoids or immunosuppressants.

Prescription Diets Must Be Fed Under Veterinary Guidance

Starting a hydrolyzed prescription diet without veterinary guidance can mask underlying conditions other than IBD, such as lymphangiectasia or protein-losing enteropathy. It also undermines the 6- to 8-week single-food trial principle, making accurate diagnosis difficult. Regular blood tests and weight monitoring should be conducted alongside dietary management.

At-a-Glance Comparison of the Top 5 Prescription Diets for Canine IBD

Item	Royal Canin HP	Hill's z/d	Purina HA	RC Anallergenic	Hill's i/d Low Fat
Protein source	Hydrolyzed poultry liver	Hydrolyzed chicken liver	Hydrolyzed soy (plant-based)	Hydrolyzed feather protein	Partially hydrolyzed chicken & egg
Molecular weight	Approx. below daltons	Approx. 3,000–5,000 daltons	Approx. 1.2–1. daltons	Approx. below 1,000 daltons	Partially hydrolyzed
Fat content	23% (high fat)	14.5% (moderate fat)	12% (low fat)	19% (moderate fat)	8.5% (ultra-low fat)
Recommended case	First-line for general chronic IBD	Dietary allergic IBD	IBD with pancreatitis	Refractory/recurrent IBD	With lymphangiectasia

Molecular weight and fat content are based on manufacturer's published data and veterinary nutrition textbooks. Even within the same brand, formulas may differ by country.

No. 1 — Royal Canin Hydrolyzed Protein (HP)

Royal Canin HP is the most widely stocked hydrolyzed prescription diet in Korean veterinary clinics. - Protein source: Hydrolyzed poultry liver (chicken and turkey) - Molecular weight: Approximately 10,000 Daltons or less - Fat content: 23% (high-fat category) - Key features: Most commonly prescribed as the first-choice option for 6–8 week dietary trials. Formulated with refined rice and fish oil (EPA and DHA) to enhance intestinal absorption and provide anti-inflammatory benefits. However, due to its high fat content, it is not suitable for cases accompanied by lymphangiectasia. It is also frequently used as a maintenance diet during the stable phase.

Dog hydrolyzed prescription food served in a stainless steel bowl

No. 2 — Hill’s Prescription Diet z/d

Hill’s z/d is a hydrolyzed prescription diet belonging to the group with the smallest molecular weight. - Protein source: Hydrolyzed chicken liver protein - Molecular weight: Approximately 3,000–5,000 Daltons - Fat: 14.5% (medium fat) - Key feature: Suitable for both diagnosing and managing dietary allergic IBD Because its molecular weight is lower than that of Royal Canin HP, it has reduced antigenicity. It should be considered first when a food antigen is suspected or when IBD is accompanied by pruritus. With a relatively low protein content of around 17%, it is not suitable for puppies or pregnant dogs.

No. 3 — Purina Veterinary Diets HA

Purina HA is a low-fat hydrolyzed prescription diet that uses plant-based protein. - Protein source: Hydrolyzed soy protein (plant-based) - Molecular weight: Approximately 12,000–15,000 Daltons - Fat content: 12% (low fat) - Key feature: Completely avoids animal protein antigens This diet is suitable for dogs with a history of reactions to poultry, beef, and fish. Due to its low fat content, it is a primary candidate for dogs with inflammatory bowel disease (IBD) accompanied by pancreatitis or hyperlipidemia. However, it cannot be used if the dog has a soy allergy.

A puppy being weighed at the animal hospital and a prescription diet package

No. 4 — Royal Canin Anallergenic

Royal Canin Anallergenic is a prescription diet with the smallest molecular weight among commercially available hypoallergenic diets. - Protein source: Hydrolyzed poultry feather protein - Molecular weight: Approximately 1,000 Daltons or less - Fat content: 19% - Key feature: The last resort when other hydrolyzed prescription diets fail to produce a response It is used for refractory inflammatory bowel disease (IBD) and food allergies that have not improved with standard hydrolyzed diets. Although its price is 1.5 to 2 times higher than other prescription diets, its efficacy has been proven in cases unresponsive to other diets. The principle of exclusive use is strictly enforced.

No. 5 — Hill’s Prescription Diet i/d Low Fat

Hill’s i/d Low Fat is a prescription diet specifically formulated for inflammatory bowel disease (IBD) accompanied by lymphangiectasia. - Protein sources: Partially hydrolyzed chicken and egg - Molecular weight: Not fully hydrolyzed - Fat content: 8.5% (ultra-low fat) - Key features: Designed for IBD with concurrent protein-losing enteropathy and hypoalbuminemia Although not fully hydrolyzed, the extremely low fat content helps prevent protein loss through the lymphatic system. It should be considered as a first-line option for IBD cases presenting with hypoalbuminemia. However, it is not suitable for use as a sole dietary antigen trial.

Key Tips for Transitioning to and Managing Prescription Diets

Transition to the new prescription diet gradually over 7–10 days by mixing it with the current food. A sudden change can worsen temporary diarrhea. - Eliminate all treats and supplements: Exposure to other proteins during the 6–8 week trial can compromise the accuracy of the results. - Check flavors in toothpaste and dewormers: Products flavored with chicken or beef can also act as allergens. - Ensure full household compliance: Even a single piece of food dropped from the dining table can force you to restart the trial from the beginning.

A pet owner gradually transitioning their dog’s food by mixing two types together.

How to Assess Efficacy — Mandatory Initial Recheck at Four Weeks

The efficacy of the prescription diet is assessed by monitoring stool frequency, body weight, and serum albumin levels. We recommend an initial recheck at four weeks and a final evaluation at eight weeks. If your pet is given any regular treats, chews, or table scraps, even once, the trial must be restarted from the beginning to ensure an accurate diagnosis. If there is no improvement after eight weeks, switch to a different hydrolyzed diet or proceed with additional diagnostic tests.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Do hydrolyzed prescription diets need to be fed for life?

No. After a trial period, if improvement is confirmed, we identify the protein your pet can tolerate by gradually reintroducing (rechallenge) a standard diet containing the same protein. During the stable phase, many pets are transitioned to a standard allergy prescription diet or a single-protein diet.

Can IBD improve with prescription diets alone, without medication?

In mild, diet-responsive inflammatory bowel disease (IBD), a significant number of patients achieve remission with dietary changes alone, such as elimination or hydrolyzed diets. For moderate to severe cases, glucocorticoids and immunosuppressants are used in combination. Whether or not the condition responds to diet is the key turning point that determines the treatment approach.

Are directly imported products the same as officially distributed domestic products?

Even within the same brand, formulas can vary by country, and direct overseas purchases may be prone to oxidation or spoilage due to temperature fluctuations during shipping. We recommend using officially distributed products obtained through a prescription from a local veterinary clinic.

Can homemade or raw diets achieve a hydrolyzed effect?

At home, it’s not possible to hydrolyze proteins into particles small enough to avoid triggering an immune response. Hydrolysis can only be achieved through industrial processes, so commercial prescription diets must be used during the trial phase for IBD.

Does giving just one piece of meat really invalidate the trial?

Yes. Even a single exposure to the antigen can reactivate the immune response, making it difficult to assess symptoms. Therefore, even tiny amounts must be strictly avoided during the trial period.

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References

[1] Hand MS et al., Small Animal Clinical Nutrition, 5th Ed, Chapter 58 Adverse Reactions to Food

[2] Ettinger SJ, Feldman EC, Cote E, Textbook of Veterinary Internal Medicine, 8th Ed, Chronic Enteropathies

[3] Fascetti AJ, Delaney SJ, Applied Veterinary Clinical Nutrition, 2nd Ed, Chapter 8 Commercial and Home-Prepared Diets

[4] Allenspach K et al., Long-term outcome in dogs with chronic enteropathies, J Vet Intern Med, 2007