title: Weekly variability of plasma and serum NT-proBNP measurements in normal dogs.
abstract: OBJECTIVE
  To determine the weekly variability of serum and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations in healthy dogs.
  
  
  METHODS
  Fifty-three normal dogs were examined prospectively. Serum (n=25) or plasma (n=28) samples were obtained for NT-proBNP assay at one week interval for 3 consecutive weeks.
  
  
  RESULTS
  Median serum or plasma NT-proBNP concentration did not change over 3 consecutive weeks. Twenty-two of 53 dogs (42%) had at least one NT-proBNP value >500 pmol/L, including 14 dogs with at least one serum NT-proBNP concentration >500 pmol/L and 8 dogs with at least one plasma NT-proBNP concentration >500 pmol/L during the 3-week sampling period. The difference between the maximum and minimum NT-proBNP value obtained over the 3-week sampling period was <100 pmol/L in 40% of dogs, between 100 and 200 pmol/L in 40% of dogs, and >200 pmol/L in 20% of dogs. Of the 19 dogs with a value >500 pmol/L on either week 1 or 2, 11 dogs (58%) had a subsequent NT-proBNP value <500 pmol/L on either week 2 or 3.
  
  
  CONCLUSIONS
  There is a high degree of variability in weekly serum and plasma NT-proBNP values in healthy dogs. Individual variability should be considered when interpreting NT-proBNP results in dogs.
authors.affiliation: University of Wisconsin, School of Veterinary Medicine, Department of Medicine, 2015 Linden Dr. Madison, WI 53711, USA. kellihanh@svm.vetmed.wisc.edu
authors.forename: Heidi B
authors.initials: HB
authors.lastname: Kellihan
authors.forename: Mark A
authors.initials: MA
authors.lastname: Oyama
authors.forename: Caryn A
authors.initials: CA
authors.lastname: Reynolds
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Stepien
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D004285:Dogs / Q000097:blood*; D005260:Female; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D010949:Plasma / Q000378:metabolism; D011446:Prospective Studies; D012016:Reference Values; D044967:Serum / Q000378:metabolism; D013997:Time Factors
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain