I have a 17.5 y/o dog (who I've owned for 16.5 of those years - she's followed me through college, career changes, and out of state moves!) who currently has a sarcoma growing between the muscle tissues of her rear left leg. She was "diagnosed" approximately 3 weeks ago with our main vet, and we just had a consult/second opinion with another vet that would be performing the surgery. She was put under anesthesia for the x-rays and she sprung back just fine, albeit a bit sore from them manipulating that leg. I have independently consulted with the two vets on her situation, and they both agree that she is a good candidate for CT + amputation if they took age out of the equation (in fact, they both thought she was closer to 9-10 years old!). She has OA in her hips, but they commented that she is already compensating roughly 10-15% for her left leg- thus, she is effectively loading 30-35% on her right leg instead of the normal 20% and seems to be doing fine with it.

She is healthy other than this sarcoma and her OA. She is still very spunky and spry - she runs, jumps, and plays despite my efforts. Within the past few days, I have noticed more discomfort with her left leg (i.e. licking, avoiding laying on it, swelling, dragging foot), so I really have to make this decision within the next week or less. It is looking like it would be $5.5k total for the CT + amputation.

Does anyone else have a dog who is a "super senior" (i.e. >14-15 y/o) that had a leg amputation? If so, what was the outcome? Am I thinking selfishly here? Is it "worth" it, considering she may die on the table or even within a few months? She's given me an amazing 16.5 years, so I owe a lot to her.. but I don't want my feelings to cloud her actual QOL.

Thanks in advance for any time and advice.