What is the most common acquired cardiac defect in dogs?

What is the most common acquired cardiac defect in dogs?

• A. Aortic stenosis
• B. Tricuspid regurgitation
• C. Mitral insufficiency
• D. Patent ductus arteriosus

Answer: (C)

The most common acquired cardiac defect in dogs is mitral valve disease (myxomatous degeneration) leading to mitral insufficiency. This degenerative change in the mitral valve leaflets causes poor closure during systole, allowing blood to regurgitate from the left ventricle into the left atrium. The resulting volume overload enlarges the left atrium and ventricle and can progress to congestive heart failure with pulmonary edema. Clinically, you often hear a systolic murmur best at the heart’s apex, and imaging typically shows left atrial enlargement with a regurgitant jet on echocardiography. The other options are largely congenital (PDA, aortic/valvular stenosis) or less commonly the primary acquired defect in dogs, which is why mitral insufficiency is the best answer.

The most common acquired cardiac defect in dogs is mitral valve disease (myxomatous degeneration) leading to mitral insufficiency. This degenerative change in the mitral valve leaflets causes poor closure during systole, allowing blood to regurgitate from the left ventricle into the left atrium. The resulting volume overload enlarges the left atrium and ventricle and can progress to congestive heart failure with pulmonary edema. Clinically, you often hear a systolic murmur best at the heart’s apex, and imaging typically shows left atrial enlargement with a regurgitant jet on echocardiography. The other options are largely congenital (PDA, aortic/valvular stenosis) or less commonly the primary acquired defect in dogs, which is why mitral insufficiency is the best answer.