Thrombocytopenia - 血小板減少 -

1) Abnormal platelet distribution (sequestration) : splenomegaly, severe hypothermia

2) Decreased platelet production (myelosuppression of one to all hemic cell lines)
・Acquired amegakaryocytic thrombocytopenia 
・Drugs (Toxicants) : 
 Predictable : chemothererapeutic agents, estrogens in dog, 
 Idiosyncratic : phenylbutazone, meclofenamic acid, trimethoprim-sulfamethoxazole
・Bone marrow replacement : neoplasia , myelofibrosis
・Megakaryocytic leukemia
・Myelonecrosis : infections, neoplasia, toxicants

3) Decreased platelet survival (accerated platelet destruction and consumption)
3-1) Immunologic (Primary and Secondary IMTP, SLE, Evan’s syndrome)
3-2) Non-immunologic
・Blood loss
・PLatelet activation with accelerated consumption or utilization 
・Localized intravascular coagulation : hemangiosarcoma, hemorrhage, thrombosis
・DIC
・Vasculitis / Endocacardiotis

4) Hemodilution 

5) Idiopathic mechanism or multifactorial (decreased production and decreased survival)
・Idiopathic thrombocytopenia of CKCS
・Infections
・Endotoxemia
・Neoplasia : carcinomas, hemangiosarcoma, and other sarcomas, lymphoma, leukemias
・Drugs
・Hypophosphatemia associated with hyperlimentation
・Anaphylaxis