I have to agree with what others had said here that if you do not know what you are doing stay away from the e-collar. There has been a great number of dogs ruined because they were not used right.

Shock collars are not about hurting the dog. They are about correcting negative behavior. Pain doesn't make the dog learn any faster.

An e-collar will work, but based on your comments I'd suggest contacting a professional.

Is this your first dog ever? If you cant keep it in a kennel for 8-12 hours a day then you might want to consider selling or giving your dog away. Just because you shock the hell out of him three or four times doesnt mean he will stay in the yard.

e-collars are a training tool and only a training tool. Most Pros and weekend trainers alike don't understand how or more importantly when to use the collar.

e-collar training

a under ground fence with a variable distance to get shocked i like one that lets it gets 10b feet from the border and once they cross that line it shocks them bad but you need to have him on a leash and let him do it a few times and yank him back

Sometime dogs develpop bad behaviors out of boredom. Digging, chewing, running away, etc... Could it be it is getting less attention or less hunting/run time with you?