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  Home > VBS Faculty > James R. Mickelson > Canine And Equine Genetics Laboratory > Calcium Oxalate Urinary Stones

Calcium Oxalate Urinary Stones



CVM VBS Mickelson Lab Oskar and Otto
Urinary stones composed of calcium oxalate 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 calcium oxalate stones compared to mixed breed dogs. Other commonly affected breeds include the Shih Tzu, Lhasa Apso, Pomeranian, poodle (miniature and toy), and terriers (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 urine and DNA samples from three breeds with increased risk for calcium oxalate stones: the Miniature Schnauzer, Bichon Frise, and Shih Tzu. We have two major goals. First, we aim to determine whether abnormalities in urinary calcium and/or oxalate are associated with stone formation in each individual breed. Based on preliminary evidence, we believe that high urinary calcium is common in canine stone-formers. This is the most common abnormality in human stone formers as well, and it is referred to as "idiopathic hypercalciuria." Our second goal is to identify genetic determinants of the disease. An understanding of the pathophysiology of calcium oxalate stones is fundamental to the development therapeutic and preventative strategies in canine breeds.

Your dog may be eligible if he/she:

  • Is a purebred Miniature Schnauzer, Bichon Frise, or Shih Tzu
  • Is not currently receiving steroid medications (ex. prednisone, dexamethasone, methylprednisone) or diurectics (ex. Lasix, hydrochlorothiazide)
  • Is not hypothyroid (thyroid medications increase urinary calcium)
  • Does not have Cushing's disease (also known as hyperadrenocorticism)
  • Cases: Has a history of calcium oxalate stones (any age permitted) OR
  • Controls: Is at least 10 years old and has never had calcium oxalate stones


We will perform free bloodwork (mini panel that includes kidney values, blood sugar, and electrolytes) and urine tests for all dogs. Please note that the urine sample will need to be fasted; we often ask that you withhold food (but not water) on the morning of the appointment, but there are other options that can be discussed. Free abdominal x-rays will also be performed in control dogs (without a history of stones) to screen for stones.

All study participants will be compensated $25 per dog.

Confidentiality will be maintained for all study participants. No individual names or medical information will be shared with anyone outside of the research group.


Even if you cannot physically come in to the UMN, you may still be able to participate in the study. If you own a dog of the aforementioned breeds that has been diagnosed with calcium oxalate stones, a simple DNA sample from your dog could be very helpful in our genetic study. We are happy to provide instructions for cheek swab DNA collection and submission to the study.

If you have further questions about this study, please contact Dr. Eva Furrow: 612-625-6222 or furro004@umn.edu. 


Dr. Furrow is a Small Animal Internist and research fellow in canine genetics at the 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 at the University of Minnesota and is currently a member of the Canine and Equine Genetics Laboratory. Drs. Ned Patterson, Jim Mickelson, Jody Lulich and Jane Armstrong are fellow collaborators in this research.
Dr. Furrow's interest in calcium oxalate uroliths was triggered by the high prevalence of this disease in certain breeds. It is a frustrating problem to treat and recurrence rates are very high. Her ultimate goal is to find better ways to prevent and treat the disease. She also has a personal attachment to one of the high-risk breeds, as her parents-in-law have always had Miniature Schnauzers.

** This study is funded by the Morris Animal Foundation

                                                                                        CVM VBS Mickelson Lab Calcium Oxalate Puppy


Related Links

Calcium Oxalate Questionnaire (Cases)

Calcium Oxalate Questionnaire (Controls)

USDA Guidelines for Importation

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