Biological variation of baseline serum cortisol concentration in healthy dogs, part 1: variance components

Introduction: ). Methods: Baseline cortisol concentrations analyzed in duplicate from 18 healthy, acclimated, client-owned dogs over a 6-week period were used to quantify biological variation for this measurand. Results: ) was 6.86%. Cortisol concentrations were not associated with age, breed, sex, neuter status, or venipuncture site (jugular vs. cephalic). Baseline cortisol concentrations were not associated with date of sampling as the study progressed. Discussion: Biological variation of baseline cortisol in dogs can be used to help interpret individual cortisol results and when establishing laboratory quality goals. Veterinarians should be aware of the potential biological variation of baseline cortisol measurements in dogs.