Evaluating preoperative coagulation panels in dogs undergoing liver lobectomy for primary liver tumors: A multi-institutional retrospective study.

Background: The objectives of this study were to: (i) Determine whether operable primary liver tumors were associated with prolongations in prothrombin time (PT) and activated partial thromboplastin time (aPTT) and (ii) determine if these secondary hemostatic abnormalities were more prevalent with specific liver tumors.

Study design: Multi-institutional retrospective study.

Animal population: Dogs (n = 359) undergoing liver lobectomy for a primary liver tumor with a preoperative coagulation panel.

Methods: Data was identified via electronic medical record review at eight veterinary teaching hospitals. Baseline dog characteristics, coagulation panel values, platelet count, emergency versus non-emergency procedure, whether the dogs received transfusion(s) of a blood product, liver lobe removed, and histopathological diagnosis were extracted from the medical record. Chi-square analysis was used to compare categorical variables between groups. Continuous variables were assessed for normality using the Shapiro-Wilk test.

Results: A total of 74 of 359 dogs (20.6%) had a prolongation in either PT or aPTT preoperatively. A total of 20 of 359 dogs (5.6%) were found to have prolongation of both PT and aPTT. Hemangiosarcoma was the only histopathological diagnosis associated with concurrent prolongations of both PT and aPTT (p < .001) in 6/16 (37.5%) dogs.

Conclusion: Coagulation panels including PT and aPTT are unlikely to detect substantial deficiencies in secondary hemostasis in most dogs with primary liver tumors except in dogs with a histopathological diagnosis of hemangiosarcoma.

Clinical significance: PT and aPTT testing is low yield as an elective preoperative screening test in dogs with primary liver tumors except in dogs where there is a hemoabdomen or high suspicion for hepatic hemangiosarcoma.