No need? Might you try to guess the answer to the following question:
According to a statistical report I read some years ago, What d you suppose was the best thing to have in your house to keep predatory humans away?
I know for home defense, but it is cruel to have an animal bred for herding or hunting kept in a tiny fenced in yard. There are plenty of good smaller dogs with are just fine for home protection, along with keeping a gun in the nightstand.