A Retrospective Study of Canine Bladder Stone Recurrence while using a Preventative Prescription Diet INTRODUCTION Canine Bladder Stones (Uroliths) 2 main types (Merck 2007) Struvite (MAP) Calcium Oxalate (CaOx) Stone Formation Struvite (Magnesium Ammonium Phosphate) Urine oversaturated with minerals Usually infection-induced (UTI) Excess urea from protein and urease- producing bacteria cause alkaline urine (Rinkardt 2004) Calcium Oxalate Concentrated urine (acidic) Risk factors causing increased calcium and oxalate excretion (Minnesota 2002) Dietary Prevention and Treatment Struvite Dissolution diet (Hill’s s/d) (Hill’s 2005) -Reduced phosphorus, magnesium, and protein -High moisture to promote diuresis -Create acidic urine (Osborne 2004) Maintenance diet (Hill’s c/d) (Hill’s 2005) -Low phosphorus and magnesium -Acidic urine (pH ) Calcium Oxalate Maintenance diet (Hill’s u/d) (Hill’s 2005) -Low oxalate, sodium, and protein -Basic urine (pH ) Bladder Stone Recurrence Struvite 20-25% within 1 year (Merck 2007) Calcium Oxalate 42% within 2 years (Minnesota 2002) Struvite Uroliths, petnutrigenomics.com Struvite Crystals, axiomvetlab.com CaOx Stones, petnutrigenomics.com CaOx Crystals, axiomvetlab.com Sarah Moser Department of Biological Sciences, York College HYPOTHESIS The c/d and u/d prescription diets will have a great effect on lowering the recurrence of struvite and calcium oxalate stones in canines at the Carlisle Small Animal Clinic Checked for recurrence by: Looking at surgical records for multiple stone removals Search of entire patient history urinalysis, radiographs, urine C&S, doctors’ notes Calcium Oxalate Data surgery records (past 10 yrs.) u/d dietno diet recurrence no recurrence recurrence no recurrence METHODS s/d diet consumer records & surgery records (past 10 yrs.) c/d dietno diet recurrence no recurrence recurrence no recurrence Struvite Data n = 35 n = 24 RESULTS Struvite Results n = 20 p = n = 15 Calcium Oxalate Results n = 10 p = n = 14 Figure 2. The recurrence of struvite bladder stones when returning back to the original diet. CONCLUSIONS 1) The Hill’s c/d and u/d prescription diets reduced the recurrence of bladder stones in canines 2) Using a binomial probability test it was determined that the struvite data were not quite significant, but the calcium oxalate data were 3) Statistics would improve with a larger sample size 4) Next step is to look at the effectiveness of other prescription diets (Purina, Waltham, Royal Canin, etc.) Figure 1. The recurrence of struvite bladder stones when using a prescription diet (Hill’s c/d diet). A binomial test was used to find a p value of Figure 3. The recurrence of calcium oxalate bladder stones when using a prescription diet (Hill’s u/d diet). A binomial test was used to find a p value of Figure 4. The recurrence of calcium oxalate bladder stones when returning back to the original diet. Literature Cited Canine Calcium Oxalate Uroliths. College of Veterinary Medicine at the University of Minnesota m endations/k9caox/home.html Canine Uroliths. Merck Veterinary Manual. manual.com/mvm/index.jsp?cfile=htm/be/ htm Prescription Diet® for Dogs. Hill’s Pet Nutrition products/pd_product_list. jsp?FOLDER%3C%3Efolder_id= &bmUI D= Osborne, Carl A., DVM Improving management of urolithiasis: canine struvite uroliths. DVM Newsmagazine. Rinkardt, Nancy E. and Houston, Doreen M Dissolution of infection-induced struvite bladder stones by using a noncalculolytic diet and antibiotic therapy. Canadian Veterinary Journal. 45: Acknowledgements Thanks to Dr. Bradley Rehnberg for mentoring this research project.