An adult, captive eastern spiny softshell turtle (Apalone spinifera spinifera) was examined for a 4-day history of lethargy and plastron discoloration. The turtle was obtunded and had pale mucous membranes, hemorrhagic nasal discharge, and petechiae on all limbs. The turtle was euthanized due to its grave condition. Necropsy revealed hemorrhagic coelomic effusion, petechiae on the serosal surfaces of the intestinal tract, and bilaterally hemorrhagic lungs. Histologic examination revealed numerous emboli of bacteria associated with fibrinocellular thrombi throughout the blood vessels of multiple tissues. The bacteria in the thrombi were slender bacilli that stained intensely acid fast. Culture of the coelomic fluid yielded Mycobacterium chelonae. Although mycobacteriosis in reptiles is typically a chronic, granulomatous disease, this case demonstrates that mycobacteriosis should be considered in reptiles presenting with acute, nongranulomatous disease. This case also describes clinically apparent hemorrhage due to disseminated intravascular coagulation, which is rarely described in chelonians.