1. Dogs treated for one to two weeks with daily injections of urethane (ethyl carbamate) subcutaneously, in doses of 0.4 Gm. per Kg. of body weight, presented a typical picture of thrombocytopenic purpura.
2. The pathologic changes consisted in numerous purpuric lesions in the small intestine and a smaller number on the skin, heart, lung, cortical zone of the kidney, epiploon, and, rarely, on the stomach and large intestine.
3. The hematologic changes occurred in the following sequence: leukocytosis, leukopenia and thrombocytopenia, and finally acute anemia coinciding with severe intestinal hemorrhage. In the final phase, the coagulation time was normal and the bleeding time very much increased.