I posted a note in The Candle Room, but we put Roo down yesterday due to the osteo. I'm happy to help any others who might be going through it understand a little more about what to expect if they decide not to treat the cancer and only provide palliative care.
A brief description: From diagnosis to euthanasia was 8 months, almost to the day. Roo had almost no symptoms at all the first two months after diagnosis. In fact we initially took him to the vet because we thought he had a mild sprain that wouldn't get better--and that's when we got the diagnosis. We took him home and he seemed to get better. We wondered if the diagnosis was wrong, but we'd known our vet for almost 20 years and all three vets in her practice agreed with the diagnosis independently. Probably wishful thinking, or denial, on our part.
After two months a slight growth appeared on his left front leg, just above his carpal joint. There was definitely no denying it now. It really didn't seem to bother him at all or affect his range of motion or activity until about 6 months after diagnosis.
That's when things took off. About two months ago the slight swelling on his leg began to grow rapidly, it limited the range of motion of the joint, and he lost use of the leg within weeks. He didn't seem to be in much pain, though it did obviously bother him so we started him on an ever escalating regimen of medications to help control the pain, and he adapted fairly quickly. Within another two weeks, however, edema developed and he started to show signs of distress.
The timeline gets a bit fuzzy in my mind here as we frantically did our best to care for him so I apologize if something doesn't add up. In the last month he started to drag his bad leg and it caused a sore to develop on his paw, adding to his discomfort. He lost 18 lbs because he had almost no appetite. Toward the end he was on a fentanyl patch and 4 other medications to make it through the day. Through it all he still had his "can do" spirit and positive energy, however, which is what made things hard.
Here's a picture of his worst leg about 2 weeks before the end: https://www.dropbox.com/s/quycikllmftpe01/IMG_1336.JPG?dl=0
Anyone who might find this and faces the same challenge, please don't hesitate to reach out. I'm not a vet, though, and won't pretend that I can give you good advice about vet things.