If you had secure fencing the dogs wouldnt be able to get out...but invisible fencing isnt secure so becareful...if the dog wants to, it can easily go though the fencing...i have watched many and if your dog has CO in it (which it doesnt look like it) invisible underground fencing will do very little if the dog wants to get out Just the other day...just so you know this is a true FYI story My brother friend has 2 GSD, the dogs were inside on the poach, a strange dog came onto the dogs property, both dogs went though the screen window to get the small dog on their own property...they are now being sued, lost home owners insurance etc...all this happened on the home owners property it may be the law but you may not win