Serial assessment of the coagulation status of dogs with immune-mediated haemolytic anaemia using thromboelastography

This study investigated the coagulation status of dogs with immune-mediated haemolytic anaemia (IMHA) over time. Thirty animals with primary IMHA were blood sampled on three occasions over a 5 day period and assays performed included prothrombin time, activated partial thromboplastin time, D-dimer and fibrinogen concentration, antithrombin activity and recalcified unactivated thromboelastography (TEG). Based on TEG, dogs with IMHA were significantly hypercoagulable vs. controls (P<0.001) and over the 5 day period, 3/4 of the TEG parameters reflected increased clotting kinetics (P ≤ 0.02). The 30 day survival of these patients was 80% and, at hospital admission, the TEG maximum amplitude (MA) was significantly higher in survivors than non-survivors (P=0.015). Each unit increase in MA was associated with an increased odds of 30 day survival of 1.13 (95%; CI 1.02-1.25). Based on TEG, most dogs with IMHA were hypercoagulable on admission and their clotting kinetics increased with time. Relative hypocoagulability identified by TEG at initial assessment was found to be a negative prognostic indicator.