Let her see the rat in the cage first and you will know by her reaction to the rat,, she might try to bite the cage,, take rat and pat to an area that will give the dog room to dispatch the rat,, worst thing is obstacles falling over and spooking the dog,,, open field is best. Cant see a rag on a fox doing any harm,, BUT again be very careful with that wheaten and pat together ,, the wheaten attacking the pup at this stage can be a disaster..hope this helps.