When it comes to urolithiasis in cats, nutrition is part of the problem and the solution. Use this chart to find the best therapeutic diet for your stone-prone veterinary patients.
Urolithiasis 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. (Editor's note: The chart below 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.)
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.
Therapeutic urolithiasis diets for cats
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.