Acute thrombosis of limb arteries in horses with sepsis: five cases (1988-1998)

A hypercoagulable condition and poor perfusion to distal extremities might occur during equine endotoxaemic or septic shock, which could cause thrombo sis of limb arteries. In our review thrombosis occurred in neonatal foals i n association with Gram-negative bacteraemia, In 3 older foals and adults, thrombosis was associated with inflammatory bowel disease, diarrhoea and to xaemia, All patients had been treated with broad-spectrum antibiotics, nons teroidal antiinflammatory drugs and i.v. crystalloid solutions. Two horses received i.v. hyperimmune plasma, A generalised coagulopathy was not suspec ted prior to clinical signs of distal limb necrosis, although thrombocytope nia occurred in 4 of the 5 cases at the time of, or shortly before, thrombo sis. Thrombocytopenia, possibly due to platelets adherence to exposed suben dothelial collagen, which induces contact activation of the intrinsic coagu lation pathway, has been described in endotoxaemic horses and foals with ga strointestinal infectious or inflammatory diseases and disseminated intrava scular coagulation. Activation of procoagulants by endotoxins, decreased blood flow to the limb s and endothelial damage, may have been responsible for a hypercoagulable c ondition leading to thrombosis in these 5 cases. The 3 enterocolitis patien ts may have had increased risk of thrombosis because of loss of antithrombi n III, haemoconcentration and acidosis.