I am in your boat and I empathize.
I’ve have my paint for 15 years. He is 21, has been completely retired for 4 years with a knee injury/chronic lameness, mild recurrent laminitis (careful diet plan/farrier care in place), and is blind in one eye. He is my heart horse and I love him dearly.
He eats, holds weight fine, and has some good days and I am just not ready.
I know he is a good candidate for euthanasia, and none of them live forever. I also know he is not a candidate for treatments that will improve his condition. I have plans in place for help to do the deed when the time comes. Having the plan helps in some way. It means I don’t have to think about the hard things when it is time. I have already made hard decisions.
I watched my younger horses bully him a bit last night, so a plan is in the works to separate him tonight after work and, if his body is willing, give him a few last warm days of summer. I don’t think another winter is in his future.
I have heard it is better to do it a day early than too late, and there is a tremendous amount of wisdom in that. I had a horse lose a long, painful battle with colic in 2011. I deeply regret that I didn’t realize sooner that the end was inevitable. It’s just so damn hard to make that call, no matter what the circumstance is.
I can tell you that no matter what I will not be ready. That is the hardest part - letting go. It can also be the kindest thing we do for them.