Clopidogrel (CL) is a newer antiplatelet drug that irreversibly inhibits the ADP receptors P2Y12 on the platelet membrane and thus has a unique mechanism from the cyclooxygenase-inhibiting effect of aspirin.A single CL dose of 10 mg/kg effectively inhibits platelet aggregation within 24 hours of administration, and a subsequent daily dose of 2 mg/kg maintained adequate platelet inhibition in healthy dogs.The use of CL in 12 dogs with pIMHA appears safe.