What is the main clinical feature of dilated cardiomyopathy (DCM) in cats?

Dilated cardiomyopathy (DCM) in cats primarily manifests as congestive heart failure, which encompasses a range of clinical signs resulting from the heart's inability to pump effectively. This condition leads to fluid accumulation in the lungs and body, often presenting as respiratory distress, lethargy, and signs of poor circulation. Cats with DCM might show symptoms such as coughing, labored breathing, and decreased activity levels due to the compromised function of the heart.

While heart murmurs may be present in some patients due to associated valvular changes, they are not definitive signs of DCM and can occur in many other cardiac conditions. Sudden weight gain may occur if fluid retention is prominent, but it is not a primary feature. Excessive grooming is more indicative of stress or other behavioral issues rather than a direct consequence of DCM. Thus, congestive heart failure is the most significant and definitive clinical feature associated with DCM in cats, making it the correct choice.