The collie we have at work he's a big heavy lad about 25 tts always coming Back with rats rabbits and recently leverets once fetched a fox cub back just puts them by the parlour door has endless stamina and isn't hyper works the cows steady until one spins an he's on the nose and has no reverse one day we where moving one off the stud bulls off the cows he turned on me I was stuck between a wall and the cow box nowhere to go ( my own fault not thinking ) and the bull came for me dog got between me an him latched to the nose until I got out got a fair bruising but never let go if that's not gam