Effects of blood donation on arterial blood pressure in retired racing Greyhounds

The purpose of this study was to evaluate changes in systolic arterial blood pressure (SABP) immediately after collection of blood for transfusion in retired racing Greyhounds. We prospectively evaluated 19 blood donor Greyhounds before and after the collection of a unit (450 mL) of blood. The SABP was measured with Doppler in the right forearm after the dogs had been in the blood collection room for a few minutes (PRE-FLOOR) and again 5-10 minutes after the dogs were placed on the table where they would be bled (PRE-TABLE). A total of 3-5 minutes after completing the blood collection, the SABP was measured again while the dogs were still in lateral recumbency on the table (POST-TABLE) and once more 60-90 minutes later, when the dogs were on the floor after completing the donation (POST-FLOOR). All dogs were monitored for clinical signs of hypotension, including depression, weakness, collapse, and pallor, for a minimum of 2 hours after donation. There was a significant difference in SABP for the group between PRE-FLOOR and POST-TABLE (P = .02) and between PRE-TABLE and POST-TABLE determinations (P = .01). There were no significant differences for any of the other time points; there were no adverse events. Therefore, we conclude that the collection of 450 mL of blood from normal Greyhounds results in a short-lived yet significant decrease in SABP, but the likelihood of adverse events is negligible.