Coco often chases rabbits and never gets near the fit, healthy ones
However, the other day she was chasing a baby that I think also had mixy so it wasn't very quick.
I had visions of her tearing it limb from limb or half killing it and me having to finish it off.
In fact she just cornered it and sat barking at it wagging her tail frantically - I think she wanted it to play
I managed to pick it up and let it go where she couldn't find it - poor thing didn't look at all well though.