Struvite crystals

Calcium oxalate crystals

Calcium oxalate crystals form in acidic urine with a low pH. They are created when calcium and oxalate combine. If calcium oxalate stones form, they cannot be dissolved with food and must be surgically removed. However, their formation can be prevented with appropriate nutrition.

Which diet should I feed my cat with urinary crystals?

Different urinary crystals form under different conditions, so the best food for your cat depends on the type of crystal your vet has identified. A urine test is essential before choosing a suitable urinary diet.

Food for struvite crystals

Food for cats with struvite crystals is usually designed to lower urinary pH, dilute the urine and contain fewer minerals that can contribute to crystal formation.

Examples include:

• Vetality Urinary Cat Food
• Sanimed Anti Struvite
• TROVET Urinary Struvite ASD

Food for calcium oxalate crystals

If your cat has calcium oxalate crystals, they need a different diet from a cat with struvite crystals. These are usually renal diets that are low in calcium and phosphorus.

Examples include:

• Royal Canin Renal
• Vetality Renal
• TROVET Renal & Oxalate RID
• Specific Kidney Support FKD
• Sanimed Renal, Liver and Stones

Combination diets for struvite and calcium oxalate

Urinary issues and bladder stones in cats can be complex, with contributing factors such as stress or obesity. Some cats may even suffer from both types of crystals. For these situations, combination diets are available to support both types.

Examples include:

• Royal Canin Urinary S/O
• Hill’s c/d Multicare
• Purina Pro Plan UR St/Ox
• Specific Crystal Management FCD

Stress can play a role in crystal formation. Hill’s has developed Hill’s c/d Urinary Stress to support both urinary health and stress management.

Additional ways to support your cat

Several factors can contribute to urinary crystals in cats, including obesity, lack of physical activity, genetic predisposition, insufficient water intake and a high-sodium diet.

For cats that are overweight, you may want to consider:

• Royal Canin Urinary S/O Moderate Calorie
• Hill’s c/d Urinary Stress + Metabolic

Cats naturally drink very little, which can lead to highly concentrated urine and promote crystal formation. Wet food can help increase fluid intake. Most urinary diets are also available as wet food, including:

• Vetality Urinary Cat Wet
• Royal Canin Urinary S/O Pouch

If your cat is picky, you can also try our urinary diet trial pack.

To help increase fluid intake, you can dilute wet food 1:1 with water. Not all cats will accept this, but even a small improvement can help.

My cat cannot switch to a urinary diet. What now?

If your cat is already on a therapeutic diet for another condition, switching to a urinary diet may not be possible. Many brands have adapted their formulas to help prevent crystal formation, including Royal Canin with S/O Index, Hill’s with S+OX Shield and Purina Pro Plan with St/Ox Safety.

If your cat has struvite crystals and prevention is not enough, you may also consider supplements such as TROVET Anti Struvite UAS. For more information, read our article on bladder crystals and stones in cats.

Need advice on urinary cat food?

Choosing the right food for a cat with urinary crystals depends on the type of crystal and your cat’s overall health. Always follow your vet’s advice before starting or changing a therapeutic diet. Still have questions? Contact our vet team at veterinarian@vetsend.co.uk.