A prospective evaluation of the prevalence of thromboemboli and associated hemostatic dysfunction in dogs with carcinoma or sarcoma

BACKGROUND: Knowledge of the prevalence of thromboemboli and the associated hemostatic status in dogs with carcinoma or sarcoma is unknown and might allow earlier intervention. OBJECTIVES: Estimate prevalence of thromboemboli and their association with hemostatic changes in dogs with carcinomas or sarcomas; estimate predictive values of hemostatic variables for thromboembolic disease in tumor‐bearing dogs. ANIMALS: Thirty‐two dogs with sarcoma, 30 with carcinoma, 20 healthy age‐controlled dogs. METHODS: Prospective cross‐sectional study. A hemostasis panel (platelet concentration, thromboelastography, fibrinogen and D‐dimer concentration, factor X, VII and antithrombin activity) was performed in all dogs. Tumor‐bearing dogs underwent complete post mortem and histopathological evaluation. Comparisons between healthy dogs and tumor‐bearing dogs with and without intracavitary hemorrhage; and tumor‐bearing dogs with and without microthrombi were analyzed. RESULTS: Thromboembolic disease was identified in 32/62 (52%, 95% CI: 39%‐65%) tumor‐bearing dogs. Microthrombi were identified in 31/62 (50%, 95% CI: 37%‐63%) dogs, 21/31 (68%, 95% CI: 49%‐83%) had exclusively intra‐tumoral microthrombi, 10/31 (32%, 95% CI: 17%‐51%) had distant microthrombi. Macrothrombi were identified in 3 tumor‐bearing dogs. Hemostatic changes potentially consistent with overt and non‐overt disseminated intravascular coagulation were identified in some tumor‐bearing dogs. D‐dimer concentrations were significantly higher (P = .02) and platelet concentration significantly lower (P = .03) in tumor‐bearing dogs with microthrombi compared to tumor‐bearing dogs without microthrombi. D‐dimer concentration above 500 ng/mL was 80% sensitive and 41% specific for the prediction of microthrombi presence. CONCLUSION: The high microthrombi prevalence and concomitant hemostatic dysfunction in dogs with carcinomas or sarcomas has not previously been reported, though the clinical importance is unknown. Increased D‐dimer concentration might increase suspicion of microthrombi.