Hydrolysed Cat Food: The Complete UK Guide (2026)

If your cat struggles with loose stools, recurring urinary issues, a dull coat, or constant hairballs, the answer often starts in the bowl. Hydrolysed cat food is now available without a vet prescription — and it is quietly becoming one of the most recommended dietary approaches for cats with food sensitivities and chronic health conditions.

This guide covers everything you need to know: what hydrolysed cat food actually is, how it works, which cats benefit most, and how to choose the right recipe for your cat’s specific needs.

What Is Hydrolysed Cat Food?

Hydrolysed cat food is a complete cat food in which the protein has been broken down into very small fragments — called peptides and amino acids — before your cat eats it. This process, known as hydrolysis, uses enzymes and water to pre-digest the protein molecules to a size so small that the immune system typically cannot recognise or react to them.

The result is a food that:

• Is highly digestible — nutrients are absorbed more efficiently
• Is less likely to trigger immune responses or food intolerances
• Supports gut health from the first bowl
• Is gentle enough for long-term everyday feeding

Hydrolysed diets were once only available on veterinary prescription, primarily from brands like Royal Canin, Hill’s and Purina. The Ultimate Plus Cat range is formulated to the same clinical standard — but requires no prescription, no vet referral, and no ongoing prescription costs.

How Is Cat Food Hydrolysed?

The Ultimate Plus Cat recipes use a process called Freshtrusion HDP (Highly Digestible Protein). Fresh meat or fish is hydrolysed before the food is made — the proteins are broken down using food-grade enzymes into short-chain peptides, then incorporated into the recipe during production.

This is different from simply using hydrolysed protein as a minor ingredient. In our recipes, hydrolysed protein is the primary protein source, delivering:

• 90–92% protein digestibility across the range
• Collagen peptides that support the gut lining
• A hypoallergenic protein profile gentle on the immune system

Which Cats Benefit Most from Hydrolysed Cat Food?

Cats with Digestive Sensitivity or Food Intolerances

Loose stools, soft faeces, bloating, and vomiting after meals are often signs of digestive sensitivity or a reaction to specific proteins in your cat’s food. Standard proteins — even in recipes labelled as sensitive — are still intact, full-sized molecules that the immune system can react to.

Hydrolysed protein bypasses this entirely. The fragments are too small to provoke an immune response, which means the gut can absorb nutrients without triggering inflammation. In independently conducted feeding trials, 92% digestibility was recorded — one of the highest figures available in a grain-free complete cat food.

Read more: Sensitive Stomach in Cats: Signs, Causes and How Diet Can Help

Cats Prone to Urinary Issues (FLUTD and Struvite Crystals)

Feline Lower Urinary Tract Disease (FLUTD) and struvite crystal formation are among the most common health issues in adult and sterilised cats. Diet plays a critical role: urine pH, magnesium levels, and hydration all influence crystal formation and bladder health.

A hydrolysed diet formulated specifically for urinary health helps maintain optimal urine pH and reduces the dietary triggers associated with crystal formation — without the ongoing cost of a prescription diet.

Read more: FLUTD and Urinary Crystals in Cats: Signs, Diet and Prevention

Cats with Dull Coats, Excess Shedding, or Recurring Hairballs

Coat quality and hairball frequency are directly affected by what a cat eats. Omega fatty acid deficiencies lead to dull, dry coats and excessive shedding — which in turn increases the volume of hair ingested during grooming, worsening hairball problems. A hydrolysed salmon recipe rich in omega-3 and omega-6, combined with fibre sources that support gut motility, addresses both problems at the source.

Read more: Dull Coat, Hairballs and Shedding in Cats: The Dietary Connection

Sterilised Cats

Sterilisation changes a cat’s metabolic rate and increases the risk of weight gain and urinary issues. All three Ultimate Plus Cat recipes are formulated to suit sterilised cats as well as intact adult cats, with appropriately balanced energy levels and targeted health support.

The Ultimate Plus Cat Range — Three Recipes, No Prescription Needed

Each recipe in the Ultimate Plus Cat range targets a specific health condition while remaining a complete and balanced everyday diet. Choose the one that matches your cat’s primary health need — you do not need to rotate between them.

Digestive Care — Hydrolysed Turkey

For cats with sensitive stomachs, loose stools, food intolerances, and digestive sensitivity. 92% protein digestibility, prebiotic FOS and MOS, and collagen peptides for gut lining support.

View Digestive Care — Hydrolysed Turkey

Urinary Health — Hydrolysed Chicken

For cats prone to FLUTD, struvite crystals, and urinary tract issues. Features our exclusive UriTract blend. 90% of cats achieved optimal urine pH in independently conducted feeding trials.

View Urinary Health — Hydrolysed Chicken

Skin, Coat and Hairball Control — Hydrolysed Salmon

For cats with dull coats, excessive shedding, and frequent hairballs. Rich in omega-3 and omega-6, with beet pulp and cellulose for hairball control. 95% of owners reported coat improvement in independently conducted 2025 trials.

View Skin, Coat and Hairball Control — Hydrolysed Salmon

How to Choose the Right Recipe

Your Cat’s Primary Concern	Recommended Recipe
Loose stools, vomiting after meals, food intolerance, digestive sensitivity	Digestive Care — Hydrolysed Turkey
Urinary crystals, FLUTD, straining to urinate, frequent urination	Urinary Health — Hydrolysed Chicken
Dull coat, excessive shedding, frequent hairballs, dry or flaky skin	Skin, Coat and Hairball Control — Hydrolysed Salmon
Not sure which to choose	Try all three with the Sample Box

If your cat has multiple concerns, start with the recipe that addresses the most urgent issue. Most cats show meaningful improvement within 4–6 weeks on the right hydrolysed diet.

How to Transition Your Cat to Hydrolysed Food

• Days 1–3: 75% old food, 25% new hydrolysed food
• Days 4–6: 50% old food, 50% new hydrolysed food
• Days 7–9: 25% old food, 75% new hydrolysed food
• Days 10–14: 100% hydrolysed food

If your cat is particularly fussy, extend each stage by a few extra days.

Hydrolysed Cat Food vs Standard Sensitive Cat Food

Many sensitive cat foods simply remove a common allergen or reduce grain. But the proteins they do include are still intact, full-sized molecules that the immune system can react to. Hydrolysed cat food goes further: the proteins are enzymatically broken down to fragments so small they are effectively invisible to the immune system. This is why hydrolysed diets produce results that standard sensitive foods often cannot.

Frequently Asked Questions

Do I need a prescription for hydrolysed cat food?

Not for the Ultimate Plus Cat range. Our recipes are available to buy directly — no vet referral or ongoing prescription required.

Is hydrolysed cat food suitable for kittens?

The Ultimate Plus Cat range is formulated for adult and sterilised cats. If you have a kitten with digestive or skin concerns, speak to your vet about appropriate options.

Can hydrolysed cat food be fed long term?

Yes. All three recipes are complete and balanced for everyday long-term feeding. They are not short-term elimination diets — they are intended as permanent diets for cats that benefit from a hydrolysed protein source.

How quickly will I see results?

Most owners report visible improvement within 3–6 weeks. Digestive changes such as firmer stools and reduced vomiting often appear sooner. Coat improvements typically take 6–8 weeks as new hair growth cycles through.

Editorial note: This article is written for informational purposes only, based on independently conducted feeding trials and consultation with UK veterinary nutritionists. It is not a substitute for professional veterinary advice. Always consult your vet if you have specific concerns about your cat’s health.

Explore the Range

Browse the Full Hydrolysed Cat Food Range
Try All Three Recipes with the Sample Box