Five cases of coagulopathy caused by consumption of indanedione (diphacinone)-based rodenticides are reported. In each case, acute onset of lethargy and respiratory distress were the predominant initial clinical signs. Thoracic radiography revealed pulmonary edema, pleural effusion, and/or pericardial effusion as consistent findings. Laboratory evaluations confirmed coagulopathies that responded to vitamin K1 therapy.