Evaluation of platelet function in horses undergoing colic surgery using the PFA-100 platelet function analyser

Acute colic in horses, especially presentations requiring surgical correction, such as large colon volvulus, very often involves defective or excess platelet activation. The PFA-100 is a new point-of-care analyser that evaluates platelet function by measuring closure time (CT) in the whole blood of healthy horses in a standardised manner. However, there are no reports on platelet function in horses with colic measured by the PFA-100. The aim of the present study was to investigate platelet function in a group of horses suffering ascending colon displacement (ACD) and who underwent surgery compared to a group of control (C) horses. Thirty ACD cases and twenty untreated clinically healthy control horses were included. Blood samples were collected from the ACD horses prior to and 24, 48 and 72 h after laparotomy. Red blood cell count (RBC), haematocrit (HCT), haemoglobin (Hb) concentration, white blood cell count (WBC), total plasma protein (TP) concentration, platelet count (PLT), platelet volume (MPV) and ADP closure time (CT-ADP) were measured. CT was determined on a PFA-100® device using collagen/ADP cartridges. There were no significant differences in RBC, PLT and MPV between C and ACD horses pre-operatively. Reduced PLT was observed in the post-operative period. The mean CT-ADP of C horses was 96.43 ± 12.53 and 91.43 ± 2.51 seconds in the ACD group prior to surgery. CT-ADP was changed after surgery whereby CT-ADP time was more than doubled. We conclude that the PFA-100® can be used to detect platelet function defects in horses.