ANALYSIS OF HEMOSTASIS IN HORSES WITH COLIC

Eight tests of hemostasis were measured in 233 horses with colic. Bloo d samples were obtained at admission and for 4 consecutive days of hos pitalization. Data were analyzed retrospectively by outcome, by broad- category diagnosis group, by small intestinal disorder, and by smaller categories for comparing specific diseases. Nonsurviving horses and h orses with the most severe forms of intestinal ischemia had changes in terpreted as hypercoagulative, the intensity of which was increased on the first and second mornings (sample times 2 and 3) after admission, when most significant differences for results of specific tests were detected. Nonsurvivors had decreased antithrombin III activity and pro longed prothrombin and activated partial thromboplastin times; those w ith strangulating obstructions also had decreased protein C and plasmi nogen activities. During hospitalization and with survival, these chan ges tended to reverse. In most horses, regardless of diagnosis or outc ome, concentration of fibrin degradation products and fibrinogen, and alpha2-antiplasmin activity increased over time. Whether these changes reflected specific effects of colic or of the acute-phase response wa s not determined. In comparisons of small intestinal disorders (proxim al enteritis, strangulations, and impactions), diagnostically distingu ishing features were not found. Likewise, in comparisons of specific d iseases (small vs large intestinal impaction, proximal enteritis vs co litis, small vs large intestinal obstruction), diagnostically distingu ishing features were not found.