Clotting times and antithrombin III activity in cats with naturally developing diseases: 85 cases (1984-1994)

OBJECTIVE: To determine the prevalence of abnormalities of in vitro prothrombin time (PT) and activated partial thromboplastin time (APTT), or antithrombin III (ATIII) activity or all 3 variables in cats; and the association of abnormalities of these variables with naturally developing diseases or disorders. DESIGN: Retrospective study. ANIMALS: 85 cats from which blood had been obtained for measurement of a coagulation profile (PT, APTT, and ATIII activity) and concentration of fibrin degradation products. PROCEDURE: Medical records from the Texas A&M College of Veterinary Medicine were reviewed to determine clinical diagnosis, results of CBC and coagulation profile, and clinical evidence of abnormal bleeding or thrombotic disease. RESULTS: 38 cats had one or more abnormality in the coagulation profile; most had multiple abnormalities. Twenty of these 38 cats had concurrent thrombocytopenia. Thrombocytopenia was identified in 9 of 47 cats in which results of the coagulation profile were normal. Most cats did not have clinical evidence of a coagulation disorder, and testing had been requested as part of a diagnostic work-up or before surgery. Diseases commonly associated with laboratory evidence of a coagulation disorder, either singly or in combination, included hepatic disease, neoplasia, and systemic infections. CLINICAL IMPLICATIONS: On the basis of laboratory evidence, hemostatic disorders develop more commonly in cats than clinical signs would suggest. Coagulation profiles may be warranted in high-risk cats to alert clinicians to potential problems.