Page 5 - AITP AutoImmune Thrombocytopenia

"Jain NC, Switzer JW.

Abstract

Autoimmune thrombocytopenia has been recognized as a distinct entity in the dog and cat. It is
characterized by: (1) clinical signs of thrombocytopenia, such as hemorrhages into the skin and tissues
and from body orifices, (2) coagulation defects related to thrombocytopenia, such as prolonged bleeding
time and poor clot retraction, (3) hematologic changes such as severe to moderate thrombocytopenia,
often blood loss anemia, and signs of increased erythropoiesis, and (4) an absence or decreased number
of megakaryocytes in the bone marrow during early phase and increased number during compensatory
phase. Megakaryocytes may also show morphologic abnormalities. Serologic diagnosis of AITP in the
dog and cat currently involves demonstration of antiplatelet antibody in serum by PF‐3 test and/or
associated with marrow megakaryocytes by a technique of direct immunofluorescence. Circumstances
leading to formation of antiplatelet antibody remain unknown. Immune‐mediated platelet destruction is
believed to occur in the reticuloendothelial system, primarily in the spleen. Treatment consists primarily
of corticosteroids and other immunosuppressive drugs. Dogs with primary AITP generally respond
favorably to such therapy."