The dog I posted above is one of three dogs we have. The other two are smaller (beagle sized) and not particularly threatening;they are pets with a pet mentality for the most part. Winston, though, is a shepherd/hound mix and has a very strong instinct for guarding. Never having owned a guard dog breed before, it's impressive to watch how he operates. With family, he is a cuddly lap dog. With visitors, he is stern at first but is learning to take our cues and relax (he's two years old and still learning). If someone broke in and we were alarmed, I have no doubt that he would act without hesitation to protect us. We left him in the yard when we weren't home at first, but now we give him the run of the house and he does fine with it. He chewed a couple minor things in the first few weeks but hasn't done anything like that for months.

We have a cat too, and when Winston was a puppy he would catch it and hold it down while it hissed, but he never harmed it. He seemed to enjoy tormenting the cat though, and didn't seem to get alarmed when the cat hooked a claw in his nose or eyelid. He pretty much ignores the cat now.