Hydrolyzed Protein Cat Food

Published Aug. 23, 2022

What Is Hydrolyzed Protein Cat Food?

Hydrolyzed protein cat food contains proteins that have been broken down to a very small size. Traditional cat food contains intact proteins of normal size. Most known food allergies are due to an abnormal reaction to intact proteins in food. The aim of a hydrolyzed protein diet is to disrupt or break down the proteins within the diet, so the immune system does not react to them.

Hydrolyzed proteins have been used in baby formula for decades for children who are allergic to cow’s milk, but their use in cat food is more recent. A vet will prescribe a hydrolyzed protein diet to aid in diagnosing and managing a cat’s food allergies. These diets are also often prescribed for cats with inflammatory bowel disease (IBD).

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Cat Food Allergies

The most common symptom associated with food allergies in cats is itching that is not seasonal and is always present. Behaviors also include licking, scratching, overgrooming, and biting. Itching can occur anywhere on the body, but the head and neck are often involved. In particular, the area around the eyes, in front of the ears, and sometimes the ears themselves will be itchy.

Skin lesions may also be present, including small crusts (miliary dermatitis), redness, papules, self-induced trauma, self-induced hair loss, ulcerations, or plaques. Less commonly, there may be gastrointestinal symptoms, including diarrhea and/or vomiting.

The treatment for food allergies in cats is to provide a diet that does not contain any allergy-inducing ingredients. Hydrolyzed protein cat foods are routinely used for this purpose.

Inflammatory Bowel Disease in Cats

Symptoms of IBD in cats can include:

  • Vomiting

  • Diarrhea

  • Bloody stools

  • Weight loss

  • Decreased appetite

  • Lethargy

Symptoms may vary in frequency and/or severity, and depend on the portion of the gastrointestinal tract affected. The symptoms of IBD are similar to many other diseases, so this diagnosis may require extensive diagnostic testing.

Cats with IBD are believed to have an inappropriate immune response to food substances, which results in symptoms. Hydrolyzed cat foods are recommended in these cases because the protein particles in these foods are reduced to such a small size that the immune system should not recognize them as a protein. If the immune system does not recognize the protein, it should not cause any symptoms.

Hydrolyzed Protein Cat Food

Common hydrolyzed protein cat food products include:

Can All Cats Eat Hydrolyzed Protein Cat Food?

Cats should be fed a hydrolyzed protein diet under the direction of a veterinarian. These foods are balanced for long-term feeding. It is important for your veterinarian to ensure that a hydrolyzed protein cat food will be suitable for your cat’s individual medical situation. Your veterinarian can also determine if a hydrolyzed protein cat food can be consumed by other cats in the home.

Is Hydrolyzed Protein Cat Food a Prescription Diet?

Currently, all hydrolyzed protein cat foods are by prescription. There are strict quality-control guidelines to ensure that all proteins in these diets are broken down appropriately. These guidelines also ensure that hydrolyzed protein foods do not contain contaminant proteins. If a diet contains contaminant proteins, the cat’s symptoms may not improve.

Hydrolyzed protein cat foods are to be used under the guidance of the veterinarian writing the prescription. Your veterinarian can advise you about the feeding of hydrolyzed protein cat foods and help you to evaluate your cat’s response.

Featured Image: iStock.com/Irina Nedikova

Leigh Burkett, DVM


Leigh Burkett, DVM


Dr. Leigh Burkett was born and raised in Northeast Tennessee. She received her undergraduate degree in Biology from Wake Forest University...

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