Review: The mechanism of blood coagulation, its disorders and measurement in poultry

Intensive genetic selection has improved productive traits in poultry and contributed to changes in systemic metabolism; however, their blood coagulation processes have received little study. The precise physiological mechanisms of haemostasis in birds remain poorly understood, but blood clotting is believed to be governed by an extrinsic tissue factor-dependent pathway, with some residual intrinsic pathway serving an ancillary function. Disorders of haemostasis are a common pathology in poultry rearing, manifested by bleeding, which most often occurs in the muscles, intramuscular fat, connective tissue and internal organs. Efficient diagnosis of haemostatic disorders in poultry remains an ongoing problem. The diagnostic methods currently in use in veterinary medicine are inadequate for evaluating haemostatic disorders. The optimisation of coagulometric methods and the availability of species-specific reagents remain significant obstacles. Furthermore, although vitamin K is essential for the synthesis of extrinsic coagulation factors and interacts with vitamin D in bone formation, it is frequently deficient in birds. The objective of the paper is to present the current state of knowledge of haemostatic disorders in poultry, and to stress the need to develop more detailed laboratory procedures and methods of producing species-specific reagents for determination of haemostatic parameters to deepen the understanding of blood clotting in birds.