Our Lab, Ronnie, came from the RSPCA a couple of years ago, very very fat but a lovely (quiet) nature aged 5.
He wouldn’t fetch either until one day it just clicked, he fetched, brought back and dropped the ball at my feet.
WOW, no wrestling the ball off him.
It appeared he’d been well trained, well looked after until his owner no longer had time for him, which is why he was fat, why his feet were delicate and why he’d forgotten how to fetch.
He still won’t fetch sticks though, it has to be a ball but he will fetch brilliantly.
He’s a lot thinner now too 😀