Originally Posted by northernmama
Did the vet explain how a heart problem could result in an abdominal bulge?
If the heart isn't working perfectly then blood can back up into the veins, which increases the pressure in the veins. This higher pressure effectively squeezes fluid out of the blood vessels into the surrounding tissues, which we see as swelling in the tissues. This fluid moves by gravity to the lowest place it can, usually the lowest part of the abdomen, so we see it as a swelling on the bottom of the abdomen.