My 18 year old sphynx, Hairry, had congestive heart failure last Sunday, but I got him to a vet in time for them to help. He's doing well on medications and I get some extra time with him.
The vet was an ordeal as their initial diagnosis was lymphoma and were going to give steroids. A friend that works there offered to come in on her day off, made them wait for radiology to report back, and figured out it was heart failure. If they had given him steroids, it would probably have killed him, so I'm extra grateful she gave him some extra attention and care. He still had to stay in an oxygenated kennel for a day and a half as the meds cleared the fluid from around his heart and out of his lungs.