Comparative hematology: studies on goats.

Results of blood coagulation and hematologic studies on 6 goats, each tested 3 times, were compared to the values seen in persons. Special blood platelet studies were done on an additional goat. Blood coagulation values in the goats and in persons were similar, with these exceptions: In the goat, activated partial thromboplastin time was shorter and thrombin time was longer; one-stage assays of factors V, VIII, and IX were very high, and platelets aggregated poorly epinephrine and ristocetin. Both platelets and erythrocytes were small. On scanning electron microscopy, the erythrocytes appeared as flat disks or triangles, occasionally having a dimpled center, compared to the deeply dimpled doughnut shape of the larger human erythrocytes. Osmotic fragility of these small erythrocytes was greater than that of their human counterparts. By transmission electron microscopy of ultrathin sections of goat buffy coat, platelets had fine structures similar to those of human platelets. Unlike in human platelets, most of the dense bodies in goat platelets were surrounded by clear vacuoles. Biochemical studies showed higher than human levels of phosphorus, chloride, sodium, alkaline phosphatase, and serum glutamic oxaloacetic transaminase.