I had an english mastiff that I had gotten when he was 8 weeks old. Had him for a little over 2 years, but then we had another child. He was a big dog and clumsy and didn't work out well with the young one (he was fine with the 2 older children though) so we had to keep him segregated most of the time and he spent too much of his life penned off in the dining room by himself and I worked a lot. We searched for a long time and found a family that had a couple dogs already and was looking for a younger mastiff- their's was getting old and had health problems and I think they knew he was on his way out. They came with their dogs and spent a couple hours at our house with him before deciding to take him.
We went out to visit him about 4 months later and boy was he happy! He remembered us and wanted to leave with us, but he really was better off with them (for his sake) as they were able to spend more time with him. A couple months later their older mastiff passed and they thanked us again as our dog (Buck) was helping them get through it. These large dogs really have a short life expectancy. We still keep in touch with them and plan to visit him more.
The reason I say this is that people have different reasons for getting rid of animals, there are just right and wrong ways of doing it. I also can relate with your feelings. I was closest with this dog and hated having to let him go, but knew he would have a better life with them. I still miss him after about 6 months, though it is nice to know that I can go visit him now and then and they keep us updated with pictures.
You have my condolences.
