RELIABILITY OF SINGLE URINE AND SERUM SAMPLES FOR ESTIMATION OF 24-HOUR URINARY URIC-ACID EXCRETION IN 6 HEALTHY BEAGLES

Urine uric acid-to-urine creatinine ratios (UUA:UC), urine uric acid c oncentrations, urine uric acid concentrations corrected for glomerular filtration rate, and urinary uric acid fractional excretions were com pared with 24-hour urinary uric acid excretions measured in 6 healthy adult female Beagles. Comparisons, using correlation analysis, were ma de when dogs consumed a 10.4% protein (dry weight), casein-based diet and a 31.4% protein (dry weight), meat-based diet. The UUA:UC, urine u ric acid concentrations corrected for glomerular filtration rate, and urinary uric acid fractional excretions were not reliable estimates of 24-hour urinary uric acid excretions during consumption of either die t. Urine uric acid concentrations in samples collected 2, 4, 6, and 24 hours after initiation of collection correlated with 24-hour urinary uric acid excretions when dogs consumed the casein-based diet; correla tion was not found at any time interval when dogs consumed the meat-ba sed diet. Therefore, determination of 24-hour urinary uric acid excret ion is recommended because UUA:UC are unreliable.