An ECG (electrocardiogram) is a diagnostic test used to assess heart rhythm disturbances. This diagnostic tool can be used to evaluate a cardiac arrhythmia. 

 

A Holter monitor allows 24 hour ambulatory monitoring of heart rate and rhythm during rest and exertion to assess for any problems. A Holter monitor may be recommended for evaluation of patients with a history of collapse or weakness with exertion. It may also be recommended in breeds that are susceptible to heart rhythm disturbances or dilated cardiomyopathy (DCM).