Coagulation abnormalities in dogs with neoplastic disease

Conventional laboratory methods were used to screen untreated tumor-bearing dogs for hemostatic abnormalities. Excluded from study were dogs with clinical evidence of bleeding. The primary site for neoplastic disease in 100 dogs studied included hemolymphatic system, skin, bone, thyroid gland, oropharynx, mammary gland, and nasal cavity. Eighty-three percent of the dogs had one or more abnormal coagulation tests. Thrombocytopenia occurred in 36 dogs and 3 had thrombocytosis. Twenty-five dogs had hypofibrinogenemia, and 25 had hyperfibrinogenemia. There were 32 dogs with prolongation of the activated partial thromboplastin time, 10 dogs with shortened prothrombin time, and 6 dogs with prolongation of the thrombin time. Sixteen dogs had positive protamine sulfate (paracoagulation) reaction, and 8% had increased plasma fibrin degradation products. The euglobulin lysis time was accelerated in 24% of the dogs, and 15% had schistocytes on blood film. These data indicate that the majority of dogs with advanced neoplasms are likely to have abnormal coagulation tests.