A 6-year-old 1-kilogram male neutered ferret (Mustela putorius Furo) was presented to the veterinary teaching hospital for a one-day history of dark black feces, hyporexia, polydipsia, and lethargy. Third-degree AV block was confirmed via ECG and echocardiogram with a ventricular rate of 37-40 BPM and atrial rate of 230 BPM. The ferret’s arrythmia and bradycardia failed to improve with medical management over the next three days. A Dextronix VVI Epicardial pacemaker (EPM) was placed to treat the third-degree AV block. The ferret recovered uneventfully. The following morning, the cardiac rhythm had unexpectantly returned to a normal sinus rhythm with a heart rate of ~200 BPM. The cardiology service confirmed that the pacemaker was working appropriately and would trigger if the heart rate dropped below 140 BPM. This remained consistent in hospital and the ferret was discharged after four days of monitoring and supportive care. Recheck four weeks later showed the ferret improving with increased energy and appetite. Recheck ECG revealed normal rate and rhythm (210 BPM) with persistent moderate cardiac insufficiency. The pacemaker was being used 5% of the time, primarily at night. There are currently no reports of a ferret returning to a normal sinus rhythm post EPM implantation. This case represents the first known report of a completely reversed third degree AV block of currently unknown etiology.