Changes in D-dimer concentration after soft tissue and orthopedic surgery in dogs

Objective: D-dimer is a specific marker of active coagulation and fibrinolysis. The objective of this study is to determine the influence of surgery on D-dimer concentration as well as to examine the relation between the magnitude of change and invasiveness of the surgical procedures. Study design: Prospective clinical study. Animals: Forty-five client-owned dogs undergoing elective neutering (n = 15), elective orthopedic (n = 15), or posttraumatic orthopedic (n = 15) surgical procedures. Methods: Dogs undergoing elective neutering, elective orthopedic, and posttraumatic orthopedic surgical procedures were enrolled. D-dimer concentration, measured immediately prior to, immediately after, and 24 hours after surgery (T0, T1, and T24, respectively), was compared within and among study groups. Results: D-dimer concentration was >250 ng/mL in 8 (18%) dogs at T0, in 9 (20%) at T1, and in 5 (11%) at T24. At T1 and T24, only 2 dogs had a D-dimer concentration >500 ng/mL, and it was <750 ng/mL in all dogs. There was no difference in the proportion of increased D-dimer concentration (>250 ng/mL) among the time points (P = 0.29). Median D-dimer concentration did not vary between time points within the groups, except in the neutering group (P = 0.029), in which T1 concentration tended to increase compared with T0 values (161 ng/dL, range 71-727 vs 122 ng/mL, range, 43-353, respectively; P =.065). Conclusion: The surgical procedures tested in this study are unlikely to cause a direct increase in D-dimer concentration. Clinical significance: Any increase in D-dimer concentration after elective neutering, elective orthopedic, and posttraumatic orthopedic surgical procedures should be regarded as clinically important and trigger investigations to detect a hemostatic derangement.