Sancho is not looking very good. He's still up and eating, and he isn't runny or coughing. But he's also taken to pacing in big, random, wandering circles, which might be a problem with arthritis or other pain. Sancho has been a really physical goat his entire life, so his joints may be giving up on him. April-goat was in a lot of pain at the end of her life, so I've seen similar before.
I put a call into the vet for guidance. It may be that I need to shoot Sancho up with painkillers and vitamins like we did for April. He won't like it when I'm doing the shot, but I don't want him suffering.
He is going to be SIXTEEN years old in February. I know I'm going to lose him at some point. I'm ok with that. I'm not ok with him suffering during the cold months when I could be doing something for him.
ETA: The vet recommended a goat-coat as a start, and perhaps a visit by him to see if there is any underlying issue that we should mitigate. I'm going to add April's Oatmeal to the prescription because warm food on a cold day and a few asprin can't hurt.