My Rhodie ridgeback was just like pnance describes. She only had one friend her whole life, back in South Africa, and only until that dog disappeared (a common occurrance there). We brought her to the USA, and until the day she went to RB she was never allowed near other dogs or children. If my cats got in her way (i.e. between her and a bag of groceries) they were chewed on. We loved her with our lives, but knew just what her limits were, and kept her extremely happy with leash walks or unleashed runs if there were no other dogs. NEVER allowed near small children, she would be so freaked if they came near her she'd bite them.

Just know what you are dealing with and never get them into that situation. Sometimes all the behaviorists in the world and various methods of help,just don't!

Now we have a rescue dog who loves everyone, except some men and other dogs when she's on a leash. She loves the dog park, is the friendliest dog we've ever had. But I keep her out of situations I know will make her anxious.