When I was an apprentice blacksmith the Master blacksmith and farrier who was training me stopped off at a house to file the feet of a donkey who was 2 years short of 50! It was the most sway backed animal I've ever seen but it still ambled around the field with Courtney cursing as he tried to catch it.
So my donkey (now named Nico the burro) could be ambling- what he does best- around for the next 27 years? I'd be 90, we could roll on our backs together so long as someone was around to help us up again...
