Determination of and correlation between urine protein excretion and urine protein-to-creatinine ratio values during a 24-hour period in healthy horses and ponies.

The research paper deals with an evaluation of the urine protein-to-creatinine (UP:C) ratio in horses and ponies to provide an estimate of urine protein excretion (UPE) over a 24-hour period. The study involves the analysis of urine samples from 11 female horses and 6 female ponies. The findings indicate a strong correlation between 24-hour UPE and UP:C ratio, suggesting that the latter could be a reliable method for estimating 24-hour UPE in these animals.

Research Methodology and Procedures

• The study involved urine collection from 11 female horses and six female ponies at 4-hour intervals over a 24-hour period.
• The total 24-hour UPE and UP:C ratio were calculated from the collected samples.
• Both these variables were also evaluated in urine aliquots collected at 4-hour intervals.
• Additionally, on two separate days, urine samples were obtained from six horses to determine the daily variation in UP:C ratio.
• The correlation between 4-hour or 24-hour UPE and UP:C ratio values was determined.
• New reference ranges were calculated for 24-hour UPE, 24-hour UP:C ratio, and 4-hour UP:C ratios based on the central 95th percentiles of observed values.

Results of the Study

• The study found a solid correlation between the 24-hour UPE (4.28 +/- 2.99 mg/kg) and 24-hour UP:C ratio (0.0 to 0.37), with a correlation coefficient (R) of 0.826, which is statistically significant (P < 0.001).
• A similar strong correlation was observed with 4-hour UPE and UP:C variables, with an R value of 0.782; confirming statistical significance (P < 0.001).
• The calculated reference ranges for UPE and UP:C ratio were found to be similar to those previously established for other species.
• The study also found minimal day-to-day variability in the UP:C ratio for the same horse, and all results were within the reference range computed using the 24-hour urine samples.

Conclusions and Clinical Relevance

• The strong correlation between the 24-hour UPE and UP:C ratios suggests that assessing the UP:C ratio is a reliable method to estimate the daily urine protein excretion in horses and ponies.
• The study also demonstrated similar reference ranges for other species, highlighting potential cross-species application of the UP:C ratio assessment.
• The minimal day-to-day variation in UP:C ratio indicates the consistency of this metric, further strengthening its clinical relevance in monitoring equine urinary health.