7 and a half years ago I was graced with a St Bernard coming into my house. Tonight I'll be going to bed without her. A couple of weeks ago she was jumping around and hurt her rear leg, we figured she pulled a muscle (or something) so we kept an eye on it. It got better and she was using it... at least until she pounced a cat or jumped around outside, then she'd limp for a bit but be fine after a few hours.
Today was really rough, she couldn't seem to get comfortable, she jumped up after rabbits twice last night. She wimpered a few times and was in pain so we took her to the vet, fortunately out vet has emergency hours. They did xrays, and it was their orthopedic surgeon who was on call so we knew we were in good hands. One look at the xrays and we knew it was bone cancer.
It wasn't in a normal area, it was right by the hock or what we'd call a knee. Saint's do not do well with three legs, even if it is one of the rear legs, so there was no real option. We could bring her home and put her on super pain killers, but honestly that wouldn't have been fair to her. We didn't even bring her out of sedation. I sat with her the entire time so she knew she was loved, it really did calm her.
And with that, I'm going to mourn the loss of my friend.