Objectives—To measure urine concentrations of sulfated glycosaminoglycans (GAGs), determine optimal storage conditions for urine samples, establish a reference range, and determine whether there is correlation between 24-hour total urine GAG excretion and the GAG-to-creatinine ratio (GCR).
Animals—14 healthy adult dogs.
Procedure—Single urine sample GAG concentrations and GCRs were measured in samples collected from 14 healthy dogs at the start of the 24-hour collection period. Twenty-four–hour total urine GAG excretions were determined from urine collected during a 24-hour period in the same 14 dogs. Total sulfated GAG concentrations were also measured in urine from these dogs after the urine had been stored at 4°C and -20°C for 1, 7, and 30 days.
Results—Urine GAG concentrations were not significantly different from baseline values after urine was stored at 4°C for up to 1 day and -20°C for up to 30 days. Neither single urine sample GAG concentration (R, 0.422) nor GCR (R, 0.084) was an adequate predictor of 24-hour total urine GAG excretion.
Conclusions and Clinical Relevance—Results of this study provide data that can be used to establish a reference range for 24-hour total urine GAG excretion in dogs and adequate conditions for sample storage. Contrary to findings in humans, there was no significant linear correlation between 24-hour total urine GAG excretion and single urine sample GCR in dogs, limiting clinical use of the single urine sample test.