Report to the American Miniature Schnauzer Club

Joe Bartges, BS, DVM, PhD, DiplACVIM, DiplACVN
Associate Professor of Medicine and Nutrition
Department of Small Animal Clinical Sciences
College of Veterinary Medicine
University of Tennessee

Urinary stone disease (urolithiasis) is common in human beings, dogs, and cats. The majority of stones occur in the kidneys or ureters in human beings, whereas the majority of stones occur in the urinary bladder in dogs and cats. Despite this difference, calcium oxalate is the most common mineral occurring in stones in human beings, dogs, and cats. More than one-half of all stones from dogs are composed of calcium oxalate, and the majority of all kidney stones in dogs are calcium oxalate. Treatment for calcium oxalate stones in human beings includes lithotripsy (shattering stones into smaller fragments) or surgery. In dogs and cats, surgery remains the treatment of choice due to unavailability and cost of lithotripsy. The Veterinary Teaching Hospital at The University of Tennessee is one of two veterinary schools that has the capability of doing extracorporeal shockwave lithotripsy (ESWL). Other types of stones (struvite, urate, cystine) can be managed less invasively; however, it is not possible currently to dissolve medically calcium oxalate stones.

Recently the National Institute of Health has requested applications concerning animal models of calcium oxalate stone disease (called an R21 grant). Often “animal models” refers to rodents; however, dogs that form calcium oxalate stone disease may represent a naturally occurring model. Miniature Schnauzers have been shown to have a familial predisposition to forming calcium oxalate stones; however, the mechanism(s) by which this occurs is not entirely known. Therefore, one aim of a proposed NIH-funded study will be to try to characterize the cause or causes of calcium oxalate stone disease in Miniature Schnauzers. We hope this will result in better means to screen Miniature Schnauzers for their potential to form calcium oxalate stones.

In addition, we will be managing an on-line health survey for owners of Miniature Schnauzers in order to identify pertinent health issues in this breed. A part of this survey will be to identify genetically related stone-forming and non-stone-forming Miniature Schnauzers. We hope to evaluate the genetics of calcium oxalate stone disease in this breed using newer genomic techniques such as microsatellite markers. This would aid breeders in screening dogs for their potential to form calcium oxalate stones, and may provide information on the genetics of calcium oxalate stone disease in human beings.

A second aim of a proposed NIH-funded study will be to develop better treatment protocols and preventative protocols. If the mechanism(s) of calcium oxalate stone disease in Miniature Schnauzers can be determined, then specific treatment and preventative strategies can be developed and applied. Currently, we are working with investigators at Georgetown University and McAllister College on medical dissolution of calcium oxalate stones, and we are able to perform lithotripsy.

The focus of our research at The University of Tennessee is concerned with causes, diagnosis, and management of urinary tract diseases, particularly urinary stone disease in dogs and cats. We have validated techniques to determine the composition of urine and have developed and validated techniques to determine how saturated urine is with stone-forming minerals. In addition, we have been involved with nutritional studies on stone disease in dogs and cats for more than a dozen years.

We believe Miniature Schnauzers may provide important information concerning cause(s) of urinary stone disease and that information from these endeavors will benefit Miniature Schnauzers and human beings.

PLEASE note that all identifying information will be collected, held and treated with ABSOLUTE CONFIDENTIALITY by the University of Tennessee so that all breeders, exhibitors and owners may be comfortable in sharing their information freely. Identifying data is being requested for research purposes only and will be used to facilitate requests for additional information should the need arise.

November 7, 2001
Updated March 18, 2002