Abstract
Characteristic symptoms due to hemostatic disorders were produced in agroup of 3 calves fed approximately 2kg of bracken fronds per head per day. Fourclinical stages, subclinical, initial, hemorrhagic and serious, were classified according tosymptoms. The circulating anticoagulant test, plasma recalcification time, thrombin titra-tion test, protamine neutralization test, tissue thromboplastin neutralization test, andanti-plasma thromboplastin test were performed on blood samples collected in each stage.Edema or hyperemia in the conjunctiva preceded a fever and bleeding. The initialstage was accompanied by a tendency for platelets to decrease. The thrombin titrationtest and protamine neutralization test showed that blood heparin was concerned with theincreasing curve of the circulating anti-coagulant test both in the hemorrhagic and theserious stages. In these stages, the anti-thromboplastin activity of heparin and the anti-plasma thromboplastin activity were stimulated alike.
