Comparison chart: Urolithiasis diets for cats

Lightspruch/stock.adobe.comUrolithiasis refers to the presence of rock-like mineral formations (i.e. uroliths or stones) within the urinary tract and falls under the feline lower urinary tract disease umbrella. When large enough, these stones can result in dysuria, hematuria and urethral obstruction.

Nutrition: enemy and ally

Pets urinate what they eat, so while the exact mechanisms behind stone and crystal formation remain unknown, food is a significant factor.1 Diets high in certain minerals and diets that predispose to very high or low urinary acidity are associated with the formation of uroliths in cats.1 But because nutrition is a part of the problem, it can also be part of the treatment plan.

Knowing the type of stone(s) affecting a given patient will help determine the course you take for treatment and prevention. Stones are named according to their mineral makeup, and in cats, the top two most common uroliths are struvite (magnesium ammonium phosphate) and calcium oxalate. The therapeutic diets in the chart below are formulated to address one or both of these types of stones.

Once you settle on a diet for a particular patient, make sure your client understands that extra food (e.g. rawhides, table scraps, treats, supplements) could thwart the food's effectiveness. Explain what their cat can (and can't) have between meals and why. And don't be shy about revisiting this topic during follow-up appointments as you monitor your patient's response to the diet-especially if the food doesn't have the effect you expected.

(Editor's note: The chart on the next page isn't exhaustive. These manufacturers produce other diets that include sterile struvite and calcium oxalate stone prevention benefits. The diets included on the chart are those that have the urinary tract as their main focus.)

Therapeutic urolithiasis diets for cats

Food

Struvite dissolution?

Struvite prevention?

Calcium oxalate prevention?

Calories

Guaranteed analysis

Link to website and other info

Dry foods

Blue Buffalo Natural Veterinary Diet W+U Weight Management + Urinary Care

YES

YES

352 per cup

• Crude protein: 38% min

• Crude fat: 11% min

• Crude fiber: 13% max

• Moisture: 9% max

• Magnesium: 0.1% max

• Sodium: 0.25% min, 0.45% max

• Vitamin E: 300 IU/kg min

• Taurine: 0.3% min

• Soluble fiber: 0.5% min

• Omega 3 fatty acids: 0.5% min

• Mmega 6 fatty acids: 2% min

• L-carnitine: 400 mg/kg min

https://bluebuffalo.com/natural-cat-food/blue-natural-veterinary-diet/wu-dry-food-for-cats/

Hill's Prescription Diet Urinary Care c/d Multicare Feline with Chicken

YES

(dissolves in as little as 7 days; average 27 days)

YES

YES

349 per cup

• Crude protein: 30% min

• Crude fat: 13% min

• Crude fiber: 1.6% max

• Calcium: 0.57% min, 0.95% max

• Phosphorus: 0.5% min, 0.9% max

• Magnesium: 0.04% min, 0.09% max

• Omega-3 fatty acids: 0.35% min

https://www.hillspet.com/cat-food/pd-cd-multicare-feline-with-chicken-dry#accordion-content-054167331-3

Hill's Prescription Diet Kidney Care k/d Feline with Chicken

YES

YES

541 per cup

• Crude protein: 26% min

• Crude fat: 20% min

• Crude fiber: 4% max

• Phosphorus: 0.3% min, 0.75% max

• Sodium: 0.4% max

• Taurine: 0.2% min

https://www.hillspet.com/cat-food/pd-kd-feline-dry

Hill's Prescription Diet Metabolic + Urinary Feline

YES

(dissolves in as little as 7 days; average 27 days)

YES

YES

289 per cup

• Crude protein: 34% min

• Crude fat: 1% min

• Crude fiber: 16% max

• Calcium: 0.5% min,

0.9% max

• Phosphorus: 0.4% min, 0.8% max

• Magnesium: 0.05% min, 0.11% max

https://www.hillspet.com/cat-food/pd-metabolic-plus-urinary-feline-dry

Hill's Prescription Diet Urinary Care s/d Feline

YES

(dissolves in as little as 6 days; average 13 days)

YES

523 per cup

• Crude protein: 3% min

• Crude fat: 23% min

• Crude fiber: 1% max

• Calcium: 0.65% min,

1.3% max

• Phosphorus: 0.5% min, 0.9% max

• Magnesium: 0.08% max

• Taurine: 0.1% min

• Vitamin E: 550 IU/kg min

• Intended for intermittent feeding only; not recommended for over 6 months

https://www.hillspet.com/cat-food/pd-sd-feline-dry

Purina Pro Plan Veterinary Diets UR Urinary St/Ox Feline Formula

YES

YES

YES

398 per cup

• Crude protein: 40% min

• Crude fat: 11% min

• Crude fiber: 4% max

• Moisture: 12% max

• Ash: 9.5% max

• Calcium: 0.9% min

• Phosphorus: 0.8% min

• Magnesium: 0.09% max

https://www.proplanveterinarydiets.com/products/ur-stox-urinary-cat-food/

Royal Canin Feline Urinary SO Dry Cat Food

YES

YES

YES

315 per cup

• Crude protein: 32.5% min

• Crude fat: 13.5% min

• Crude fiber: 4.5% max

• Moisture: 9.5% max

• Magnesium: 0.08% max

https://www.royalcanin.com/us/cats/products/vet-products/feline-urinary-so-dry-cat-food

Wet foods

Blue Buffalo Natural Veterinary Diet W+U Weight Management + Urinary Care

YES

YES

136 per 5.5-oz can

• Crude protein: 8.5% min

• Crude fat: 2.5% min

• Crude fiber: 4% max

• Moisture: 78% max

• Vitamin E: 50 IU/kg min

• Taurine: 0.1% min

• Ascorbic acid (vitamin C): 20 mg/kg min

• L-carnitine: 100 mg/kg min

https://bluebuffalo.com/natural-cat-food/blue-natural-veterinary-diet/wu-wet-food-for-cats/

Hill's Prescription Diet k/d Feline with Chicken

YES

YES

177 per 5.5-oz can

• Crude protein: 6% min

• Crude fat: 4% min

• Crude fiber: 1.5% max

https://www.hillspet.com/cat-food/pd-kd-feline-with-chicken-canned

Hill's Prescription Diet Metabolic + Urinary Vegetable & Chicken Stew

YES

(dissolves in as little as 7 days; average 27 days)

YES

YES

60 per 2.9-oz can

• Crude protein: 5.5% min

• Crude fat: 1.8% min

• Crude fiber: 3.4% max

https://www.hillspet.com/cat-food/pd-metabolic-plus-urinary-feline-vegetable-and-chicken-stew-canned

Hill's Prescription Diet Urinary Care s/d Chicken Flavor

YES

(dissolves in as little as 6 days; average 13 days)

YES

203 per 5.5-oz can

• Crude protein: 8.5% min

• Crude fat: 7.5% min

• Crude fiber: 1% max

https://www.hillspet.com/cat-food/pd-sd-feline-canned

Purina Pro Plan Veterinary Diets UR Urinary St/Ox Feline Formula (original canned)

YES

YES

YES

189 per 5.5-oz can

• Crude protein: 10% min

• Crude fat: 5% min

• Crude fiber: 1.5% max

• Moisture: 78% max

• Magnesium: 0.03% max

https://www.proplanveterinarydiets.com/products/ur-stox-urinary-cat-food/

Royal Canin Feline Urinary SO Morsels in Gravy

YES

YES

YES

65 per 5.8-oz can

• Crude protein: 6% min

• Crude fat: 3.5% min

• Crude fiber: 2% max

• Moisture: 82% max

https://www.royalcanin.com/us/cats/products/vet-products/feline-urinary-so-morsels-in-gravy-canned-cat-food

Source: Manufacturers' packaging and marketing materials

Reference

1. Little S, Kornya M. Non-Obstructive Feline Lower Urinary Tract Disease. Available at: https://www.winnfelinefoundation.org/docs/default-source/cat-health-library-educational-articles/non-obstructive-feline-lower-urinary-tract-disease.pdf?sfvrsn=2. Accessed Aug 30, 2019.

Sarah Mouton Dowdy, a former associate content specialist for dvm360.com, is a freelance writer and editor in Kansas City, Missouri.