Characterisation of clotting factors, anticoagulant protein activities and viscoelastic analysis in healthy donkeys

Abstract

Background: Studies have demonstrated differences in commonly measured haemostatic parameters between donkeys and horses. Whether clotting factors, anticoagulant protein activities and thromboelastography parameters also differ between species is still unknown.

Objectives: To characterise haemostatic parameters in healthy donkeys and to compare these with those in horses.

Study design: Cross-sectional study.

Methods: Clotting factors (V, VII, VIII, IX, X, XI and XII), and antithrombin III, Protein C and Protein S activities were measured in 80 healthy Andalusian and crossbred donkeys and 40 healthy Andalusian crossbred horses with assays based on human deficient plasmas. Thromboelastography was performed in 34 donkeys using a coagulation and platelet function analyser.

Results: Donkeys had shorter activated partial thromboplastin time (mean ± s.d. 33.4 ± 5.2 s vs. 38.8 ± 4.2 s; P<0.001) and higher Factor VII (1825 ± 206 vs. 1513 ± 174; P<0.001), IX (142 ± 41 vs. 114 ± 28; P<0.05) and XI (59.4 ± 14.0 vs. 27.2 ± 6.3; P<0.001) activities, whereas horses showed higher Factor X (130 ± 32 vs. 145 ± 23; P>0.05) and XII (96 ± 21 vs. 108 ± 15; P<0.001) activities. Antithrombin III (204 ± 26 vs. 174 ± 29; P<0.001), Protein C (33.16 ± 10.0 vs. 7.57 ± 1.70; P<0.001) and Protein S (median [interquartile range]: 7.8 [5.8-9.3] vs. 6.2 [5.2-7.0]; P<0.001) activities were higher in donkeys. Activated clot time (175 [159-189]), time to peak (6.5 [5.8-7.8]) and clot formation rate (26.9 [16.9-36.4]) in donkeys were shorter than reported values in horses.

Main limitations: Haemostatic pathways could not be fully evaluated in donkeys because some tests are unavailable. Certain fibrinolytic parameters (plasmin, plasminogen, etc.) have not been characterised in donkeys and this may have affected our results.

Conclusions: The haemostatic system in donkeys differs from that in horses and extrapolation of reference values between these species is not appropriate.

Keywords: Protein C; Protein S; antithrombin III; clotting factors; donkey; horse; sonoclot.