What is a common sign of congestive heart failure?

Swelling in limbs is a common sign of congestive heart failure due to fluid accumulation in the tissues, a condition known as edema. When the heart is unable to pump effectively, blood can back up in the veins, leading to fluid buildup in various parts of the body, particularly in the limbs. This is often observed in the lower legs and paws of animals suffering from heart failure.

The other choices do not typically relate to congestive heart failure in the same way. While animals in heart failure may experience changes in appetite or weight, these are more variable and not as consistently indicative of the condition as limb swelling. Frequent urination can occur in some instances due to fluid overload or the impact of certain medications used to manage heart failure, but it is not a direct sign of the heart failure itself. Weight gain could occur due to fluid retention, but it is not as immediate a sign as the visible swelling in the limbs associated with edema.