One of the effects of heart failure is fluid retention, which in turn causes increased pressure on the heart, and symptoms such as coughing and abdominal swelling.
 
One of the priorities in the management of heart failure is to reduce fluid retention. The most important thing is that you do NOT feed your pet any food with a high salt content. Especially snack foods prepared for human consumption, such as pork pies.

By the time heart failure is diagnosed, the body's compensation system may have kicked in already, with the effect of placing added stress on the heart. Until the compensation system can be controlled with drug therapy, your vet may recommend a period of complete rest for your dog.
 

Once drug therapy has started to work, it's likely that your vet will recommend a return to normal or near-normal exercise, as it remains important to promote good circulation and exercise the heart.
 

Your vet will recommend an appropriate exercise regime in each case.