Why does a dog's heart enlarge? - briefly
A dog's heart can enlarge due to conditions such as dilated cardiomyopathy or valvular disease, which cause the heart to work harder and become larger over time. This enlargement is a response to increased pressure and volume load on the heart.
Why does a dog's heart enlarge? - in detail
A dog's heart can enlarge due to several reasons, primarily related to cardiac disease. The most common cause of an enlarged heart in dogs is dilated cardiomyopathy (DCM), a condition that weakens and thins the heart muscle, leading to its enlargement. This progressive disorder affects the left ventricle, causing it to stretch and become larger to compensate for reduced contractility. As a result, the heart struggles to pump blood efficiently, leading to congestive heart failure if left untreated.
Another significant cause is valvular heart disease, often seen in smaller breeds like Cavalier King Charles Spaniels and Poodles. This condition involves the deterioration of the heart valves, typically the mitral valve, which can lead to backward flow of blood (regurgitation). The left atrium enlarges to accommodate the increased volume, eventually causing the entire heart to dilate.
Less commonly, hypertrophic cardiomyopathy (HCM) can cause heart enlargement in dogs. Unlike DCM, HCM involves the thickening of the heart muscle, particularly the left ventricle. This thickening can obstruct blood flow and lead to an increase in heart size.
Regular veterinary check-ups are crucial for early detection and management of these conditions. With appropriate treatment, including medication and lifestyle adjustments, many dogs with enlarged hearts can live comfortable and extended lives.