Gas gangrene due to Clostridium haemolyticum in a cat with aortic thromboembolism treated using clopidogrel and rivaroxaban

A 12-year-old Bengal cat with unclassified cardiomyopathy presented for signs consistent with aortic thromboembolism (ATE). It was treated with clopidogrel and rivaroxaban as antithrombotic therapy, combined with narcotic analgesia and frusemide. After initially making a clinical improvement, the cat's condition suddenly deteriorated, with a presumptive diagnosis of clostridial myonecrosis. We posit that ischaemia due to ATE allowed dormant clostridial spores in the left hindlimb to germinate and multiply vegetatively, resulting in the elaboration of potent Gram-positive exotoxins, resulting in the clinical syndrome of gas gangrene, with emphysematous change in the affected limb. Samples collected following euthanasia confirmed the presumptive diagnosis, and Clostridium haemolyticum was isolated after prolonged anaerobic broth culture. The authors propose that benzyl penicillin be given intravenously to cats with ATE as bacterial prophylaxis to prevent this unusual but devastating sequela developing.