A 7 year old male castrated domestic shorthair cat was presented to the Cornell University Hospital for Animal’s Cardiology Service for evaluation of a recent history of a murmur, arrhythmia, and acute respiratory distress. Ventricular premature complexes and a right axis shift were seen on ECG, and a severely dilated right atrium and ventricle were found on echocardiography. Thoracic radiographs showed pleural effusion and persistent consolidation of the right middle lung lobe. Arrhythmogenic right ventricular cardiomyopathy (ARVC) was presumptively diagnosed, the patient was euthanized and this diagnosis was confirmed with histopathology. Gross necropsy also showed a right middle lung lobe torsion. This report discusses the diagnostic evaluation of this cat, with an overview of both diseases that have been rarely reported in cats, and never reported together.