[header] How to keep a dog in the yard [title] Observe your dog while he is in the yard. [step] Figure out how your dog is getting out of your yard, sit by a window and watch him while he is outside. Try not to let him see you or he may not reveal his escape route. 
As you watch, pay attention to where your dog goes and what he does. This should give you clues about his preferred method of escape.