Stress raises urine cortisol and protein levels in healthy dogs

Abstract

BACKGROUND: Recently, urine protein:creatinine ratios (UPC) were shown to be lower in urine samples from dogs collected at home (AH) as compared to those collected in hospital (IH). Stress-inducing procedures and travel to the hospital have been hypothesized to cause prerenal proteinuria. OBJECTIVES: Evaluate patient stress using urine cortisol:creatinine ratios (UCCr) and correlate UCCr to UPC in urine samples obtained AH and IH. ANIMALS: Thirty-six healthy, client-owned dogs. METHODS: Prospective, non-masked study. Two voided urine samples were obtained (AH and IH). Complete urinalysis as well as UPC and UCCr were performed. Clients graded their dogs' stress level AH, in transport, and IH. RESULTS: The UCCr was significantly higher in IH samples than in AH samples (P&#x2009;<&#x2009;.0001), but UPC was not significantly different between AH and IH urine samples (P = .14). In all samples and in both collection settings, UCCr was not significantly correlated with UPC. Travel time and time IH were not correlated with change in UCCr or UPC. In 8 dogs with borderline or overt proteinuria, no significant difference was found in UPC between settings, but UCCr was significantly higher in IH samples. CONCLUSIONS AND CLINICAL IMPORTANCE: The UPC was not higher when measured in urine samples collected IH compared to AH. Dogs had higher UCCr IH, but UCCr was not associated with UPC. Stress, as estimated by UCCr, did not affect proteinuria. Further evidence is needed to support the claim that stress may result in proteinuria in healthy dogs.