I've got a neighbor who has a little Border Terrier that absolutley HATES anything and everything. Occassionally, the dog will get loose and attack my much larger and extremely sweet Border Collie. After taking the abuse several times, I told my BC to defend herself against the BT and she grabbed the BT by the scruff and shook her senseless. I will tell you honestly, that if that little dog gets loose while my girls are free-ranging, I will not hesitate to let my BC defend them. the neighbor has full knowledge of this too and I will not feel guilty in the slightest...........