My brother saved a dog hung up on a chain and his dog sadie has started treating him like her favorite toy. Link is twice the size of her, but she will grab the skin on his neck and drag him around. We can't get her to stop. The only thing we can think of is to put a spike collar on him so at least she will get a bite back. But is there a better way? He will cry and we have to physically make her let go. Then she goes right back.