Haemostatic mechanisms of the newborn foal: reduced platelet responsiveness.

This research investigates the coagulation processes in newborn foals, indicating their blood clotting mechanisms are immature at birth, and hence, they may be at risk of developing bleeding disorders related to platelets.

Introduction and Objectives

• The study was aimed at exploring the state of haemostatic mechanisms (mechanisms that stop bleeding) in newborn foals during their first week of life.
• It was designed to specifically monitor whole blood platelet counts, coagulation profiles, and in vitro platelet function tests in the foals.

Methods

• Samples of blood were taken from newborn foals at different intervals during their first week of life for tests.
• The variables that were measured in these tests included platelet counts, mean platelet volumes, thrombin-induced malondialdehyde production, prothrombin times, and partial thromboplastin times.
• The team also evaluated platelet aggregation responses to serotonin, arachidonic acid, adrenaline, adenosine diphosphate, and collagen.

Results

• The results showed that platelet counts, mean platelet volumes, and thrombin-induced malondialdehyde production were not different from those in adult mares, indicating that these functions are developed at birth.
• Prothrombin and partial thromboplastin times were slightly longer in neonatal samples than in mare samples, though not significantly.
• Platelet aggregation responses to serotonin, arachidonic acid, and adrenaline did not change during the study period, but aggregation responses to adenosine diphosphate and collagen increased progressively over the first week of life.
• Adrenaline only diminished adenosine diphosphate-induced aggregation during the first 12 hours of life.

Conclusion

• The results indicate that the haemostatic mechanisms in equine neonates are immature at birth, meaning that these young horses’ mechanisms to halt bleeding are not fully functional at birth.
• During the maturation period, these equine neonates may be at risk of developing bleeding disorders associated with platelets, warranting further attention to their health and potentially informing future interventions and treatments.