The relationships between sediment findings and culture results and the presence of proteinuria in canine urine samples

Fulton, E. A., Weir, W. , Czopowicz, M. and McBrearty, A. R. (2023) The relationships between sediment findings and culture results and the presence of proteinuria in canine urine samples. Journal of Small Animal Practice, (doi: 10.1111/jsap.13669) (PMID:37632274) (Early Online Publication)

Abstract

Objectives: To assess relationships between urine sediment and microbial culture findings and the presence of proteinuria in canine urine samples, and to assess the change in the percentage of proteinuric samples and urine protein-to-creatinine ratio when urine abnormalities resolve. Materials and Methods: Canine urine samples collected via cystocentesis and submitted for culture and contemporaneous urinalysis (including urine protein-to-creatinine ratio) were retrospectively identified. Dogs receiving corticosteroids were excluded. Associations between haematuria (red blood cells>5/high-power field), pyuria (white blood cells>5/high-power field), presence of microorganisms on microscopy, active sediment, and positive culture and proteinuria (urine protein-to-creatinine ratio>0.5) were investigated. Patient characteristics were considered possible confounders. In dogs with repeat urinalysis, the associations between active sediment and positive culture resolution on proteinuria and urine protein-to-creatinine ratio were assessed. Results: One hundred and ninety-two of 491 samples were proteinuric (39.1%). Age was positively associated with proteinuria. In the multivariable analysis corrected for age, active sediment was the only variable significantly associated with proteinuria (adjusted odds ratio: 2.12; 95% confidence interval: 1.44 to 3.11); however, only 49.8% of samples with active sediment were proteinuric. Neither resolution of active sediment nor positive culture were associated with reduced proportions of proteinuric samples (from 57.9% to 42.1% and from 40.0% to 25.0%, respectively) or significant reductions in urine protein-to-creatinine ratio (median change: −0.16 and −0.14, respectively). Clinical Significance: Attributing proteinuria to urinalysis abnormalities or a positive urine culture in canine cystocentesis samples is not supported by our findings, and could result in alternative causes of proteinuria (e.g. renal proteinuria) being overlooked.

• Item Type: Articles
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McBrearty, Dr Alix and Fulton, Miss Emily and Weir, Professor Willie
• Authors: Fulton, E. A., Weir, W., Czopowicz, M., and McBrearty, A. R.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Journal of Small Animal Practice
• Publisher: Wiley
• ISSN: 0022-4510
• ISSN (Online): 1748-5827
• Published Online: 26 August 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Journal of Small Animal Practice 2023
• Publisher Policy: Reproduced under a Creative Commons license