There are many ways to stop or prevent this. One effective way I guess is through socialization. This is how it goes, http://dogtime.com/socialization.html
first of all you have to be an only child if you are pretend that you never have someone to play with and if it doesn't work try to make a paper dog and pretend your having fun with it outside .Then...
The things you have to recognize is if it is nice or not if it is a mean guard dog; to me you should see if you like the color, age, breed, and the sex you should also see if it is nice with little...