A Holter monitor is a portable ECG device worn by a pet which will continuously record heart rate and rhythm (often for up to 24 hours). Its extended recording period is useful for detecting occasional heart rhythm disturbances (called arrhythmias) which would be difficult to identify in the shorter period of time provided by a standard ECG. Our veterinary cardiologist will use this information, together with other testing to determine the nature and severity of your pet's heart disease and create the best possible treatment plan for any arrhythmias.