The Minnesota Urolith Center (MUC) at the University of Minnesota has received its 2 millionth urinary stone sample, also known as a urolith, an achievement made possible by decades of support from long-time partner Hill’s Pet Nutrition and submissions from more than 50,000 veterinary clinics in 103 countries.

The 2 millionth sample is an ammonium urate stone from Gizmo, a 4-year-old Shih Tzu living in New Jersey, submitted by Dr. Brett Lynn and team at MountainView Veterinary Hospital in Denville, New Jersey. These types of stones are typically caused by blood vessel abnormalities in the liver or by genetic mutations that interfere with the normal clearance of uric acid.
“This milestone speaks to the vast number of pets who suffer from urinary stones and to the dedication of veterinarians, owners, the MUC team, and our partner, Hill’s Pet Nutrition, to doing our best to understand and stop stones,” said Dr. Eva Furrow, co-director of the MUC.
Founded in 1981 at the University of Minnesota College of Veterinary Medicine, the MUC has pioneered the investigation and development of minimally invasive ways to diagnose, remove, and prevent urinary stones. It maintains the largest database of animal uroliths and provides complimentary analysis of nearly 100,000 submissions each year. This is made possible largely by a philanthropic educational grant from Hill’s Pet Nutrition.
“At Hill’s Pet Nutrition, our mission to help pets live long, healthy lives is fundamentally rooted in scientific research and strong veterinary and university partnerships,” said Dr. Karen Shenoy, global chief veterinary officer for Hill’s Pet Nutrition. “The MUC’s milestone of 2 million submissions perfectly reflects this shared dedication, and we are incredibly proud to support their pioneering work to advance urinary health for pets globally.”
In its 45-year history, the MUC’s impactful work has improved the lives of countless pets, including major breakthroughs in using therapeutic foods to dissolve stones and help reduce the risk of their recurrence. This progress relies on data and insights gathered from analyzing 2 million urolith samples, which feed directly into ongoing joint research between the MUC and Hill’s Pet Nutrition. By analyzing global trends in stone composition, dietary factors, and underlying metabolic drivers, researchers continuously translate these real-world diagnostic findings into increasingly advanced, science-backed nutrition.
In addition to advancing therapeutic nutrition, research from the MUC has produced other accomplishments, such as pioneering several techniques for noninvasive stone removal, including being the first to develop two forms of urohydropropulsion; uncovering genetic mutations that result in early-onset stone development in certain dog breeds; and, more recently, exploring how the urinary microbiome can influence the formation of stones.
“We are committed to protecting pets from environmental threats such as harmful additives in foods, soils and medications; researching underlying causes to understand how to prevent disease; and developing the most advanced and least invasive therapies because we believe that all life is precious,” said Dr. Jody Lulich, co-director of the MUC.