title: Measurement of urinary urea nitrogen content as an estimate of the amount of total urinary nitrogen loss in dogs in intensive care units.
abstract: OBJECTIVE
  To investigate whether urinary urea nitrogen (UUN) content can be used to accurately estimate total urinary nitrogen content in hospitalized dogs.
  
  
  METHODS
  Prospective, cohort study.
  
  
  METHODS
  24 client-owned dogs admitted to an intensive care unit of a veterinary teaching hospital.
  
  
  METHODS
  Indwelling urinary catheters and closed collection systems were placed for the purpose of monitoring urine output. Urine was collected during a 24-hour period from each dog. For each collection, the total volume was measured. Urine was analyzed for urea nitrogen content at an in-house laboratory, using standard methods for determination of BUN content. Total urinary nitrogen content was determined by another laboratory, using Kjeldahl's method. Correlation between UUN content and total urinary nitrogen content was evaluated by use of linear regression analysis.
  
  
  RESULTS
  Total urinary nitrogen content adjusted for metabolic body weight ranged from 0.21 to 2.21 g/ kg0.75/d (mean +/- SD, 0.81 +/- 0.46 g/kg0.75/d). Adjusted UUN content ranged from 0.05 to 1.50 g/kg0.75/d (0.54 +/- 0.38 g/kg0.75/d). Total urinary nitrogen content was highly correlated with UUN content (R2, 0.88; P < 0.001).
  
  
  CONCLUSIONS
  Measurement of UUN content can be used to estimate total urinary nitrogen content in a clinical setting. Furthermore, critical illness in dogs is associated with substantial catabolism of endogenous proteins.
authors.affiliation: Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6010, USA.
authors.forename: K E
authors.initials: KE
authors.lastname: Michel
authors.forename: L G
authors.initials: LG
authors.lastname: King
authors.forename: E
authors.initials: E
authors.lastname: Ostro
mesh_terms: D000818:Animals; D001806:Blood Urea Nitrogen; D002408:Catheters, Indwelling / Q000662:veterinary; D015331:Cohort Studies; D004283:Dog Diseases / Q000652:urine*; D004285:Dogs; D006762:Hospitals, Animal; D007362:Intensive Care Units; D009584:Nitrogen / Q000652:urine*; D011446:Prospective Studies; D014508:Urea / Q000652:urine*; D014546:Urinary Catheterization / Q000662:veterinary
chemical_list: D014508:Urea; D009584:Nitrogen