Variations in urinary gamma glutamyl transferase/urinary creatinine ratio in horses with or without pleuropneumonia treated with gentamicin.

The research study examines the variations in the composition of a horse’s urine–specifically the uGGT/uCR ratio–upon receiving gentamicin treatment for pleuropneumonia, and compares it to the ratio in healthy horses. The study indicates that an increase in the uGGT/uCr ratio doesn’t automatically indicate the need to adjust or stop gentamicin treatment, barring certain conditions.

Experimental Setup

• The research involved measuring the urinary GGT/urinary creatinine (uGGT/uCR) ratio in three different groups of adult horses: four healthy ones, six healthy ones undergoing gentamicin treatment, and nine suffering from pleuropneumonia also receiving gentamicin treatment.
• The ratio was measured on Days 1, 3 and 10. Additionally, the plasma creatinine and gentamicin trough concentrations were also recorded on the same days.

Comparative Findings Across Groups

• The normal horses in the study had a higher uGGT/uCr ratio than previously reported normal values. According to the study, the sick horses being treated for pleuropneumonia showed a significantly higher uGGT/uCr ratio than any of the normal horses included in the study.
• Both groups of horses that received gentamicin treatment showed similar percentage increases in uGGT/uCr ratio during the treatment period. The most notable increases in this ratio were recorded between treatment Days 1 and 3. This increase was primarily due to increased activities of uGGT rather than a decrease in uCr concentration.

Implications for Gentamicin Treatment

• A crucial finding in this study was that increases in uGGT activity and uGGT/uCr ratio occurred without any abnormalities in serum creatinine or gentamicin trough concentrations.
• This suggested that an elevation in the uGGT/uCr ratio in horses receiving gentamicin treatment doesn’t necessarily indicate the need for changing or halting the treatment. However, this assumption holds true only as long as any increases in plasma creatinine concentration stay below 0.3 g/l and gentamicin trough concentrations remain under 2 micrograms/l.