2016 ACVIM Forum Research Abstract Program

Jean Hall 1 , Dale Fritsch 2 , Maha Yerramilli 3 , Edward Obare 3 , Murthy Yerramilli 3 , Dennis Jewell 2 . 1 Oregon State University, Corvallis, OR, USA, 2 Hill's Pet Nutrition, Inc., Topeka, KS, USA, 3 IDEXX Laboratories, Inc., Westbrook, ME, USA A prospective 12-month clinical trial was performed in clientowned dogs with IRIS stage 1 chronic kidney disease (CKD) to measure their ease of transition to a commercial renal protective food and to assess the effects of food on renal biomarkers and quality of life attributes. Dogs with IRIS stage 1 CKD (n = 36) were transitioned over 1 week from various grocery brand foods to a modified protein, low phosphorus, antioxidant enriched test food (Prescription DietÒ k/dÒ, Hill's Pet Nutrition, Inc.). At months 0, 3, 6, 9, and 12 owners completed a questionnaire to assess their pet's acceptance of the test food and their dog's quality of life. Renal biomarkers, including serum creatinine (Cr), blood urea nitrogen (BUN), and symmetric dimethylarginine (SDMA), and urinalysis parameters, including urine specific gravity (USG) and urine protein:creatinine ratio (UPC), were measured. Of the 36 dogs initially enrolled, 35 (97%) transitioned to the test food. Pets moderately or extremely liked the test food 88% of the time, ate most or all of the food 84% of the time, and were moderately or extremely enthusiastic while eating 76% of the time. Dogs consuming test food showed a decrease in serum Cr and BUN concentrations across time (both P = 0.01) and a decrease in serum SDMA concentration and USG across time (both P = 0.09). All serum renal biomarkers (Cr, BUN, SDMA) were decreased (P ≤ 0.05) from baseline at 3 months, and remained decreased from baseline at 12 months in dogs completing the study (n = 20). This study shows that dogs with IRIS stage 1 CKD readily transition to a commercial renal food, and decreasing serum biomarker concentrations suggest improvement in kidney function. In addition, owners reported improvement in a consortium of overall health and quality of life attributes (P < 0.01) and hair and coat quality attributes (P < 0.01). Decreased glomerular filtration rate in chronic kidney disease (CKD) reduces renal phosphorus excretion, leading to increased total body phosphorus retention and eventually hyperphosphatemia. In addition of promoting parathyroid hormone synthesis, hyperphosphatemia stimulates the synthesis of fibroblast growth factor 23 (FGF-23), a phosphaturic/hypophosphatemic hormone. There are no reports on serum FGF-23 in healthy dogs or in dogs with CKD. The goal of this study was to measure serum FGF-23 concentrations in healthy dogs and in dogs with CKD, and to determine its association with serum phosphorus concentrations and severity of renal disease based on IRIS staging of CKD. We hypothesized that serum FGF-23 will be increased in dogs with CKD, that its concentrations will be proportional to CKD severity, and that it will be an early marker of altered phosphorus metabolism.