Calcium Oxalate Urinary Stones

Dr. Furrow and SchnauzersUrinary stones composed of calcium oxalate (CaOx) are common in dogs. Certain canine breeds have a strikingly high prevalence of disease, while others appear protected. For example, the Miniature Schnauzer and Bichon Frise have greater than 20 times the risk of developing CaOx stones compared to mixed breed dogs. Other commonly affected breeds include the Shih Tzu, Lhasa Apso, Pomeranian, poodle (miniature and toy), Dachshund, and terrier (e.g. Yorkshire, Cairn, Jack Russell). These breed predispositions strongly support underlying genetic risk factors for the disease. Our project currently involves the collection of DNA samples from dogs with a history of CaOx stones (cases) and dogs that have never formed this stone type (controls). We aim to compare the DNA of these two groups to identify genetic determinants of the disease. An understanding of the pathophysiology of CaOx stones is fundamental to the development therapeutic and preventative strategies in canine breeds.

Hereditary Calcium Oxalate Urolithiasis, Type 1

English BulldogThe Canine Genetics Lab is proud to announce the development of a genetic test for Hereditary Calcium Oxalate Urolithiasis, Type 1Hereditary Calcium Oxalate Urolithiasis, Type 1 (CaOx1) is an autosomal recessive genetic disorder that greatly increases the risk for formation of CaOx urinary (bladder or kidney) stones.  CaOx1 is rare across the dog population as a whole, but it is the most common cause of CaOx urinary stones in English Bulldogs. We have also identified the mutation in the American Staffordshire Terrier, Boston Terrier, Bullmastiff, Havanese, Rottweiler, and Staffordshire Bull Terrier; we believe that it is likely also present in additional breeds related to the bulldog lineage. 

Participation & Compensation


Shih TzuCases: Any breed of dog with CaOx stones at any point in their life is eligible to participate. We would love a small DNA sample that can be collected either at home with cheek swabs or by a veterinarian as a blood sample. It can be sent in from anywhere in the country or even outside of the United States. If you are interested in participating, we can send you cheek swab kits at no cost. Please contact Dr. Furrow (see information below) or e-mail us at

Prior Funding

About the investigator

Dr. Eva FurrowDr. Furrow is a Small Animal Internist and Assistant Professor at the University of Minnesota College of Veterinary Medicine. She first became interested in the genetic basis of canine diseases when she was an undergraduate at Harvard University. She was offered a summer position in the Section of Medical Genetics at the University of Pennsylvania. One of her roles that summer included assistance in a study on the genetic muscular disease myotonia congenita in Miniature Schnauzers. Dr. Furrow later attended the University of Pennsylvania Veterinary School where a NIH-Merck grant enabled her to continue research on genetic diseases. Dr. Furrow completed her Internal Medicine residency and PhD at the University of Minnesota and is currently a member of the Canine and Equine Genetics Laboratory. Dr. Furrow's ultimate goal is to find better ways to prevent and treat genetic diseases. She also has a personal attachment to one of the high-risk breeds, as her parents-in-law have always had Miniature Schnauzers.

If you have further questions about this study, please contact Dr. Eva Furrow: 612-625-7493 or

Contact Us

Canine Genetics Lab
University of Minnesota
1988 Fitch Ave
AS/VM 295
St. Paul, MN 55108


Learn more about the work of the Minnesota Urolith Center, which has received more than one million bladder stones for diagnosis and strives to minimize pain and avoid invasive surgery.