Μ.G.Κritsepi, Α.F.Κoutinas

Primary or idiopathic immune-mediated thrombocytopenia (IMT) is a typical autoimmune disease characterized by moderate to severe thrombocytopenia, increased patelet-associated antibody, reduced circulating platelet, distruction by splenic macrophages and maxima thrombopoiesis. The formation of antibodies against platelet membranes is its main cause. Canine IMT, being a disorder of primary hemostasis, is manifested with petechiae and ecchymoses or hemorrhages of the skin, mucosal membranes and eyes. The disease, through frequently wel tolerated by dogs, remains a potentiallly life-threatening illness. Secondary IMT is usually associated with drugs, live vaccines, infections, and neoplasms and can be resolved after elimination of the underlying offending agent. IMT should be suspected in dogs presented with severe thrombocytopenia after excluding concurrent vaccinations, medications or systemic diseases. A tentative diagnosis of IMT can be confirmed by measuring antiplatelet (preferably platelet-associated) antibody leves. Treatment, that shoud be individualized, is dependant on the number of platelets and the severity of clinical picture. Glucocorticoids, immunosuppressive agents, danazol and vincristine are commonly used medications. Emergency or refractory cases may require splenectomy, platelet transfusion, intravenous γ-globulins or plasmapheresis. The disease can be transient, recurrent or chronic. The long-term prognosis of chronic refractory IMT is always guarded.