Objectives:
To determine the weekly variability of serum and plasma n-terminal pro-b-type natriuretic peptide (nt-probnp) concentrations in healthy dogs.
Animals, materials and 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.