train the dog, without treats. use praising for a reward. start out making him sit, start out short periods of time, and extend the time period as you work with him/her. then move on to a 25' leash ( a piece of rope will work). make the dog sit, step back a few feet and give the command to heel or come. gently tug on the lead and praise the dog once it gets to you. back up further each time. once the dog is doing good at 25' start training without the lead.

Once the dog will sit and come, work on "heeling" use a choke chain, keep it high on the neck right behind their ears. Pace around the yard saying heel and keep it's head at your waist. Just a gentle tug on the choke chain will pinch a pressure point if the chain is high on the neck. Use a 4' stick or pole to tap the dog on the rear to get it to line up with you. Dont let the dog get ahead and keep im right beside you. Work every day for no more than 20 minutes at a time. In two or three months there will be no need for a shock collar. It takes a little effort but it's very rewarding when you can take your dog anywhere and not have to worry about it messing up or gettin killed. I could tell my dog to sit, go to the store and come back and he'll be in the same spot I left him. If I take him somewhere I use a 6' leash and he'll stay right beside me with no pulling and acting up.

If a shock collar isn't used properly it can make the dog worse. You really need to have a dog trained before a shock collar will even work to begin with.