EVALUATION OF URINE GAMMA-GLUTAMYL TRANSPEPTIDASE-TO-CREATININE RATIOAS A DIAGNOSTIC-TOOL IN AN EXPERIMENTAL-MODEL OF AMINOGLYCOSIDE-INDUCED ACUTE-RENAL-FAILURE IN THE DOG

The potential diagnostic utility of the urine gamma-glutamyl transpept idase (GGT)-to-creatinine ratio was evaluated in an experimental canin e model of aminoglycoside-induced nephrotoxicity. A therapeutic dosage of gentamicin resulted in a twofold increase in the mean urine GGT-to -creatinine ratio that was not associated with clinically significant nephrotoxicity. In dogs each given a nephrotoxic dosage of gentamicin, an increase in mean urine GGT-fo-creatinine ratios approximately thre e times baseline values preceded clinically significant abnormalities in serum creatinine, urine specific gravity, and urine protein-to-crea tinine ratio. The urine GGT-fo-creatinine ratio appears superior as an early indicator of aminoglycoside-induced nephrotoxicity. Further stu dies in canine clinical cases are warranted.