Cardiovascular, haematological and biochemical responses after large volume blood collection in horses.

This research paper investigates the physiological effects on horses following a large volume blood collection. The conclusion suggests that the removal of 20 mL/kg of blood – around 25% of total blood volume – if done appropriately, does not cause negative acute or chronic changes to their health.

Methodology and Findings

• The research was conducted on five healthy horses from which 20 mL/kg of blood was collected.
• The total volume of blood removed was approximately 25% of the total blood volume of each horse.
• Cardiovascular, hematological and biochemical variables were closely monitored during the blood collection procedure and for the following 31 days.
• It was found that most variables were altered as a response to the blood volume loss. Despite these changes, the value ranges mostly remained within the accepted, published reference ranges.
• This signifies that even though physiological changes occurred post blood collection, these changes did not deviate from what is usually observed in healthy horses.

Recovery Time

• The recovery of the altered variables to their initial pre-collection levels was observed to be rapid.
• Most alterations were found to return to their normal levels within the period of 24 to 48 hours post blood collection.

Conclusion

• The researchers concluded that removal of blood volumes of less than or equal to 20 mL/kg does not result in any negative acute (short-term) or chronic (long-term) physiological alterations in healthy donor horses.
• This suggests that horses possess an efficient physiological system that adequately compensates when a substantial volume, approximately a quarter, of blood volume is removed – whether for the purposes of blood donation or for the production of plasma.