He had surgery 15 months ago, after the tumor was discovered. The vet just closed him back up because the cancer was wrapped around his intestines and he couldn't remove any of it. The biopsy showed it was a type of cancer that would not respond to any type of treatment, something called "undifferentiated adenocarcinoma". We took him home and have provided hospice care for well over a year.
He was given a few months, but survived much longer than anyone expected. He was doing well, up until a couple days ago. He started really going downhill and it was obvious he wasn't going to last much longer, so we had to take him to the vet. I thought having such a long time to prepare would make it easier, but it hasn't. He was doing great for so long that I was convinced he would just go on and on and it was really hard to accept the end.