Why does it have to be quiet when a veterinarian listens to a pet's heart?
Abnormal heart or lung sounds which could indicate disease can often be very subtle and difficult to hear. When a dog pants, the lung sounds heard through the stethoscope can drown out some of these more subtle sounds. Your veterinarian may gently hold your dog's mouth shut so the panting stops, and the heart and lungs can be listened to much more effectively. Also, the pet needs to be still, or the sound of the pet's hair rubbing against the end of the stethoscope can produce interfering sounds. For similar reasons, it is important that the exam room itself also be quiet and extraneous noise eliminated.