Also, your dog needs to meet unfamiliar dogs on a regular basis. (dogstardaily.com)
One simple way to socialize pups is to introduce them to unfamiliar dogs in a familiar environment, i.e. their own back yard. (agvethospital.com)
Active prevention on your part can be accomplished by not allowing your dog's toys or water and food bowls to be accessed by unfamiliar dogs. (dogbreedz.com)