The aim of the current study was to determine canine reference intervals for prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, and antithrombin (AT) according to international recommendations. The STA Satellite(R) coefficients of variation of within-laboratory imprecision were 3.9%, 1.3%, 6.9%, and 5.1% for PT, APTT, fibrinogen, and AT, respectively. At 4 degrees C, citrated specimens were stable up to 8 hr for whole blood and 36 hr for plasma, except for APTT, which increased slightly (<1 sec). Nonparametric reference intervals determined in citrated plasma from 139 healthy fasting purebred dogs were 6.9-8.8 sec, 13.1-17.2 sec, 1.24-4.30 g/l, and 104-188% for PT, APTT, fibrinogen, and AT, respectively. Based on Passing-Bablok comparison between STA Satellite and STA-R Evolution(R) using 60 frozen specimens from a canine plasma bank, the corresponding reference intervals were transferred to the STA-R Evolution: 7.1-9.2 sec, 12.9-17.3 sec, 1.20-4.43 g/l, and 94-159% for PT, APTT, fibrinogen, and AT, respectively.