Diet is one of the most effective ways to prevent painful urinary stones in cats, particularly struvite stones. According to Gram Research analysis of current evidence, keeping cat urine slightly acidic through special food ingredients called acidifiers, balancing minerals properly, and encouraging cats to drink more water all help prevent stone formation. While struvite stones became much less common after the 1980s when pet food companies started using these strategies, recent reports show they’re increasing again, suggesting some modern foods may not be using these proven prevention methods effectively.
A new review in the Journal of Animal Science examines how diet helps prevent urinary tract problems in cats, particularly painful kidney stones made of struvite crystals. According to Gram Research analysis, the key is keeping cat urine slightly acidic through special ingredients called acidifiers, while also balancing minerals and encouraging cats to drink more water. The research shows that while struvite stones became less common after the 1980s when pet food companies started using these strategies, recent reports suggest they’re increasing again. Scientists are working to find the right balance between effective ingredients and what pet owners want to see on food labels, while ensuring these additives don’t harm cats’ long-term health.
Key Statistics
A 2026 review in the Journal of Animal Science found that dietary acidification strategies implemented in commercial cat foods from the 1980s onward significantly reduced struvite urinary stone cases, though recent US reports indicate struvite stones are increasing again.
According to the 2026 review, preventing feline urinary stones requires a three-part dietary approach: controlling urine acidity through acidifiers like sodium bisulfate and DL-methionine, balancing mineral levels, and encouraging water intake to dilute urine.
The 2026 review notes that while sodium bisulfate is both an effective urinary acidifier and supports water intake through its sodium content, ‘clean label’ consumer trends may discourage its use despite having no documented health concerns.
The Quick Take
- What they studied: How different ingredients and strategies in cat food can prevent painful urinary stones, especially the most common type called struvite stones
- Who participated: This was a scientific review that analyzed existing research about cat urinary health and commercial cat food formulations—not a study with live cats
- Key finding: Diet is one of the most important tools for preventing urinary stones in cats. Keeping urine slightly acidic, balancing minerals properly, and encouraging cats to drink more water all help prevent stone formation
- What it means for you: Choosing the right cat food may help prevent your cat from developing painful urinary tract problems. Talk to your veterinarian about foods designed to support urinary health, especially if your cat has had urinary issues before
The Research Details
This was a comprehensive review article, meaning scientists looked at all the existing research about how diet affects cat urinary health and stone formation. Rather than conducting their own experiments, the researchers gathered information from many previous studies and expert knowledge to understand what we know about preventing urinary stones in cats.
The review focused on three main ways diet helps prevent stones: controlling urine acidity (pH), managing the amount of minerals in urine, and encouraging cats to drink more water. The scientists examined different ingredients used in commercial cat foods, including special compounds called acidifiers that make urine more acidic, which helps prevent struvite stones from forming.
The researchers also looked at the challenges pet food companies face when trying to make foods that prevent urinary problems while also meeting other nutritional needs and responding to consumer preferences for ‘clean label’ products with fewer synthetic ingredients.
Understanding how diet prevents urinary stones is important because these stones cause real suffering in cats and are a leading reason people take their cats to the veterinarian. By reviewing all the scientific evidence together, researchers can help pet food companies make better products and help cat owners make informed choices about their pets’ nutrition.
This is a review article published in a respected scientific journal (Journal of Animal Science), which means it summarizes and analyzes existing research rather than presenting new experimental data. The strength of this type of article depends on how thoroughly the authors reviewed the scientific literature and how fairly they presented different viewpoints. The authors appear to have considered both the benefits and potential concerns of different dietary strategies, which shows balanced analysis.
What the Results Show
The research confirms that diet is one of the most effective ways to prevent urinary stones in cats. The key strategy is keeping urine slightly acidic through special ingredients called acidifiers, such as DL-methionine, sodium bisulfate, and phosphoric acid. These ingredients work by changing the pH of the urine, making it harder for struvite crystals to form and stick together into stones.
When pet food companies started using these acidifying strategies in the 1980s and 1990s, the number of cats developing struvite stones dropped significantly. However, recent reports from the United States show that struvite stones are becoming more common again, suggesting that some modern cat foods may not be using these proven strategies effectively.
The review also emphasizes that preventing stones requires a three-part approach: controlling urine acidity, balancing mineral levels (especially magnesium, phosphorus, and calcium), and encouraging cats to drink more water. When cats drink more water, their urine becomes more dilute, which reduces the concentration of minerals that form stones.
Another important finding is that while some acidifying ingredients work well, there are concerns about using too much of certain compounds over a cat’s lifetime. For example, excessive amounts of inorganic phosphorus or DL-methionine might cause long-term health problems, though more research is needed to understand these risks fully.
The review identifies a significant challenge facing the pet food industry: the tension between effective urinary health strategies and consumer preferences for ‘clean label’ products. Many pet owners want to see fewer synthetic or chemical-sounding ingredients on food labels, but some of the most effective and safest acidifiers (like sodium bisulfate) sound artificial to consumers, even though they’re safe and effective. Meanwhile, some acidifiers that sound more natural may carry potential health risks that aren’t well understood.
The research also highlights that predicting whether a specific cat food will prevent stones is difficult. Scientists have mathematical equations that can estimate urine pH based on food ingredients, but these equations don’t account for important real-world factors like how much water an individual cat drinks or their eating habits. This means the only truly reliable way to test if a food prevents stones is to feed it to cats and measure their urine—a process that’s expensive and time-consuming for pet food companies.
This review builds on decades of research showing that diet affects cat urinary health. The major breakthrough came in the 1980s when scientists discovered that acidifying cat food could prevent struvite stones. This discovery led to widespread changes in commercial cat food formulations and a dramatic decrease in struvite stone cases throughout the 1990s and 2000s. However, this new review notes a concerning trend: struvite stones are increasing again in recent years, suggesting that some of these proven strategies may be slipping away in modern commercial foods, possibly due to changing ingredient choices or formulation priorities.
This review has several important limitations to understand. First, it’s a summary of existing research rather than a new study with cats, so it can only be as good as the research it reviews. Second, the review doesn’t provide specific numbers about how many cats are affected by urinary stones or how effective different dietary strategies are in real-world situations. Third, much of the research on long-term health effects of acidifying ingredients is limited, so scientists can’t make definitive statements about whether using these ingredients throughout a cat’s life is completely safe. Finally, the review notes that there’s significant variation in mineral content across different ingredient sources, and scientists don’t fully understand how well cats absorb minerals from different foods, which makes it harder to predict exactly how a food will affect an individual cat’s urinary health.
The Bottom Line
Based on this research, veterinarians should recommend cat foods specifically formulated to support urinary tract health, particularly for cats with a history of urinary problems. These foods should aim to keep urine slightly acidic, balance mineral levels appropriately, and encourage water intake. Pet food companies should prioritize urinary health in their formulations and consider using proven acidifiers like sodium bisulfate, even if they sound less ’natural’ on labels. Cat owners should discuss urinary health with their veterinarian and choose foods designed for this purpose, especially for cats at higher risk. The confidence level for these recommendations is moderate to high based on decades of research showing diet’s impact on urinary health.
Cat owners should pay attention to this research, especially if their cat has had urinary tract problems before or if they have a breed known to be at higher risk for urinary stones. Veterinarians should use this information when recommending foods to clients. Pet food companies should prioritize these findings when developing new products. However, cats without a history of urinary problems and those eating high-quality commercial cat foods may not need to make changes.
If a cat switches to a urinary health-focused food, changes in urine chemistry can occur within days to weeks. However, preventing stone formation is a long-term commitment—cats need to eat the right food consistently throughout their lives to maintain protection. If a cat has already developed stones, dietary changes may help prevent new stones from forming, but existing stones typically require veterinary treatment.
Frequently Asked Questions
What causes urinary stones in cats and how does diet help prevent them?
Urinary stones form when minerals in urine crystallize and clump together. Diet prevents this by keeping urine slightly acidic (which stops struvite crystals from forming), balancing mineral levels, and encouraging cats to drink more water, which dilutes urine and reduces mineral concentration.
Are acidifiers in cat food safe for long-term use?
Most acidifiers used in commercial cat foods are safe, but the 2026 review notes that excessive amounts of certain compounds like DL-methionine or inorganic phosphorus may raise long-term health concerns. Sodium bisulfate appears safe with no documented health risks. Talk to your veterinarian about your cat’s specific food.
Why are urinary stones becoming more common in cats again?
The 2026 review suggests that recent increases in struvite stones may be due to changes in commercial cat food formulations, possibly driven by ‘clean label’ trends that discourage synthetic acidifiers, or shifting priorities away from urinary health in product development.
How can I tell if my cat food is designed to prevent urinary stones?
Look for foods labeled as supporting urinary tract health. These foods should have controlled mineral levels (especially magnesium and phosphorus) and ingredients that acidify urine. Ask your veterinarian to recommend specific brands formulated for urinary health, especially if your cat has a history of urinary problems.
How long does it take for a urinary health diet to work in cats?
Changes in urine chemistry can occur within days to weeks of switching foods. However, preventing stone formation requires consistent long-term feeding of the right diet throughout your cat’s life. If your cat already has stones, dietary changes help prevent new ones but won’t dissolve existing stones.
Want to Apply This Research?
- Track your cat’s urinary health by recording any signs of urinary problems (straining, frequent urination, blood in urine) and noting which food your cat is eating. If your cat has had urinary issues, log the date you switched to a urinary health-focused food and any changes in symptoms over the following weeks and months.
- If your cat has a history of urinary problems, use the app to set a reminder to purchase and feed only foods specifically formulated for urinary tract health. Log your cat’s water intake by noting how often you refill their water bowl, since encouraging drinking is part of preventing stones. Set a monthly reminder to discuss urinary health with your veterinarian.
- Create a long-term tracking system that monitors your cat’s urinary health indicators monthly. Log any urinary symptoms, the specific food being fed, estimated water intake, and veterinary check-up results. Use this data to identify patterns and discuss trends with your veterinarian during annual visits.
This article summarizes scientific research about feline urinary health and diet but is not a substitute for professional veterinary advice. Urinary tract diseases in cats require proper diagnosis and treatment by a licensed veterinarian. If your cat shows signs of urinary problems (straining, frequent urination, blood in urine, or inability to urinate), contact your veterinarian immediately. Before making changes to your cat’s diet, especially if your cat has a history of urinary problems or other health conditions, consult with your veterinarian to determine the best food for your individual cat’s needs. The information in this article is based on a scientific review and reflects current research, but individual cats may respond differently to dietary changes.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.