Ventricular ectopy in a German Shepherd dog

A case of spontaneous ventricular ectopy was diagnosed in a four-month-old, entire, female, German Shepherd. An arrhythmia was detected during routine cardiac auscultation. Electrocardiography revealed ventricular premature complexes, occurring singly, as couplets, or in runs of non-sustained ventricular tachycardia. The dog exhibited no physical signs of cardiac disease. Cardiac and metabolic causes of ventricular arrhythmia were investigated by echocardiography and by serum biochemistry and electrolytes. Parameters measured were within accepted normal ranges. Mexiletine, propranolol, procainamide were used singly or in combination in an attempt to control the arrhythmia. Response to these treatments was poor when monitored by sequential electrocardiographs for six months. The dog remains well at the time of writing, and the frequency and severity of the arrhythmia appears to be reducing without medication.