The first thing you need to perform accurate auscultation is a good stethoscope. You should also have a good hearing sense which develops in time. Your stethoscope is your own property; with comfortable ear tips and preferably both a diaphragm for high-frequency noise and a bell for maximizing low-frequency noise (ex. gallops and murmurs).
To perform auscultation requires a quiet room where noise intrusions are minimized. You should kindly ask everyone around to be quiet while you auscultated and the owners to avoid touching or stroking the pet. Be aware that hair coat friction mimics lung sounds and when dogs are panting or cats are purring. If a dog is panting you should wait until the excitement vanishes (if possible) and purring can be solved with a gentle blow of air in the cat’s face.
Dogs and cats are the best auscultated when they are standing or sitting. To differentiate cardiac murmurs from lung sounds observe the animal and its respiratory pattern. Before you learn how to spot abnormal sounds you first need to know how to recognize the normal sounds. Therefore, it’s highly advisable to examine animals with your stethoscope when they are perfectly healthy.
Keep in mind that kittens and puppies produce louder lung noise which may be confused with a disease. When listening to the lungs, always count the respiratory rate and rhythm. Any absence of sounds could indicate lung lobe or total lung collapse, or the presence of masses of fluid inside the pleural cavity. Physiological inspiratory sounds are low-pitched and soft. Expiratory sounds can be even lower and softer. There are two types of normal sounds – vesicular and bronchial. Putting your stethoscope over the trachea will give you a general idea of what bronchial lung sounds are like. Vesicular sounds are heard on the periphery and appear like ‘wind blowing through trees.
Heart auscultation is most successful if you know where the specific points should be detected. The examination usually starts on the left side and afterward on the right side. In small animals, there are two normal heart sounds – S1 and S2 and any addition is a sign of a disease.
It takes time and determination to master the art of auscultation, but the benefits of proper auscultation are grand so it’s worth investing your time and patience into learning!