I've had great luck with pound poochies: they somehow seem to "know" that unless they are adopted, they are going to die, and seem to be grateful for the reprieve and protective of their new parents.
Ours do fine when out on walks, or over at relatives homes who also have pets, but Lord help anyone, or any thing, trying to get into our back yard that they don't know - and no, they have never gotten to know the lawn maintenance guys.
There is a German Shephed rescue operation in the area that gets GS's out of pounds and adopts them out. We're going to start with them. Hubby really wants a GS.