Identification of hypercoagulability in dogs with primary immune-mediated hemolytic anemia by means of thromboelastography.

OBJECTIVE

To evaluate whole blood hemostasis by means of thromboelastography in dogs with primary immune-mediated hemolytic anemia (IMHA) to determine whether these dogs had evidence of hypercoagulability prior to the administration of immunosuppressant medications, blood transfusion products, or anticoagulant agents.

DESIGN

Evaluation study.

ANIMALS

11 client-owned dogs admitted to a teaching hospital for management of primary IMHA and 20 clinically normal dogs.

PROCEDURES

Citrated whole blood samples were obtained from all dogs for performance of kaolin-activated thromboelastography. Citrated plasma was harvested from blood samples of dogs with IMHA for plasma-based coagulation testing, including activated partial thromboplastin time, prothrombin time, D-dimer concentration, fibrinogen concentration, and antithrombin activity.

RESULTS

Compared with control dogs, dogs with primary IMHA had evidence of hypercoagulability as indicated by a significantly lower median (range) clot formation time (0.8 seconds [0.8 to 2.0 seconds] vs 1.9 seconds [1.3 to 3.8 seconds]), higher median angle (76.1° [59.2° to 84.6°] vs 64.0° [45.4° to 71.0°]), higher median maximum amplitude (75.9 mm [66.3 to 86.3 mm] vs 55.7 mm [49.9 to 63.6 mm]), and higher median clot strength (15,000 dyne/cm(2) [9,900 to 31,400 dyne/cm(2)] vs 6,100 dyne/cm(2) [4,900 to 8,700 dyne/cm(2)]).

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs with primary IMHA had hypercoagulability as demonstrated by thromboelastography at the time of initial diagnosis and prior to treatment. Such hypercoagulability may be a precursor to clinically evident thrombosis as a complication of the disease process.