ABSTRACT
Normal heart sounds in dogs and cats are the S1 sound, associated with closure and tensing of the AV valves and associated structures at the onset of systole, and the S2 sound, associated with closure of the aortic and pulmonic valves following ejection (see Chapter 1 and 14, p. 19). Proficiency in recognizing abnormal heart sounds and their origin is not easily achieved1-4, but this is a skill that can provide important clinical insight. In animals with a murmur or other abnormal heart sounds, it is especially important to understand the cardiac cycle events associated with these sounds and to identify the timing of systole (between S1 and S2) and diastole (after S2 until the next S1) in the patient.
