My friend and i walk our dogs together and they get on well together but, my friends dog is a 6 month old staffie crossed with an american bull dog and she keeps biting the ears and neck of my little westie when we are out, this then upsets my cocker spaniel who likes to protect the westie and the cocker spaniel is the top dog so my friends dog doesnt go after her only the westie. so, we have to keep shouting at her to stop, she does but then goes straight back for more. My friend sadly only has one tone of voice and so her dog takes no notice of her at all so it is left to me!. I dont want to have to stop walking together so any tips of how we can stop this?