My story is similar. 2 weeks ago I lost one of my 2 bunnies suddenly. Both bunnies I have had for 11 years and both appoaching 12 years old. My other bunny is still here. He seemed confused and depressed that his companion just disappeared. Now he has arthritis and his movement is virtually non existant. He stays in his wee pen all day and does not move to toilet so pees where he is sitting. His arthritis appears to be getting worse and he is on loxicom and nerve pain meds too. He is still eating and responding to me and licking me to let me know he still loves me. But I feel his quality of life is not so good and he misses his companion dearly. I always felt fine with being out at work all day because they had each other......but now I feel it is selfish of me to hold on to him. I fear the pain letting him go will torture me but also need to consider his quality of life. It's so hard saying goodbye when you are not ready. At least I gave him good innings and he will be reunited with his life companion at the rainbow bridge. Just doesnt make the decision any easier!