Aloha! You're speaking to Dr. Michael Salkin
I'm sorry to hear this about Heidi. In both humans and dogs, kidney failure is often seen along with heart failure. As the heart fails the kidneys receive less of a blood supply (become malnourished) and fail. Uremic toxins build up in our patient's bloodstream, our patient becomes nauseated and uncomfortable and anorexia is the result.

Treating heart patients such as Heidi can be quite difficult if her kidneys have failed as I expect they have. We would need to diurese Heidi - administer IV fluids in an attempt to stimulate urine production and uremic toxin removal. However, administering IV fluids to the extent in which her kidneys would benefit may well overload her heart.

Unfortunately your options are limited at this time. You can have her tested for kidney failure and if found begin careful IV diuresis. The outcome would be uncertain. This is tricky and intensive care. And, yes, it may be time for her to be put down. I understand that her quality of life has suffered dramatically presently and I would consider euthanasia a kindness if you chose that path.

Please respond with further questions or concerns if you wish. I know how difficult this is for you at this time.