Some training collars can harm a dog if they are not used appropriately or are the wrong size; so, you should research training collars thoroughly before choosing one.

Some common dog training collars are: the prong collar, the Halti, the Gentle Leader, the choke collar and the electronic collar.

Prong Collar

This collar is made up of metal prongs that have been linked together. When you apply a pulling pressure to the collar (via the leash), it gives the dog a little pinch that is meant to duplicate the effect of a mother dog's teeth when she grabs here pup by the scruff of the neck.

The prong collar is a safe and effective training tool as long as the fit is correct and the collar is used appropriately. The prong collar should not be used if your dog is one to consistently yank at his leash.

The prong collar should fit snugly against the dog's neck. A properly fitted collar should leave approximately ½ of a finger space in between your dog's neck and the prong tip. A collar that is any looser than that won't do its job and will needlessly chafe the dog's skin.

Halti and Gentle Leader

Both the Halti and Gentle Leader head halter devices look a lot like the harnesses that are used to control horses. While the prong collar is designed to condition behavior and movement, the head halter is designed to restrict or restrain your dog's movements. The thought behind the halter's design is that if you can control the head, the body will follow its movement.

When you pull on the attached leash the device closes the dog's mouth and restrains his head. These types of collars are great for dogs that lunge, bite or display other aggressive behaviors.

There are drawbacks, however, to using a head halter device. Most dogs will not take very easily to any device that positions a strap over its nose. You may have to struggle with your dog many, many times before he will submit to wearing it.

Another drawback is that pulling at your dog's head makes it a lot more likely that you'll inadvertently injure the dog's neck or back. To avoid injury, you should always make sure you're restraining your dog in the correct manner.

Choke Collar

The choke collar is one of those dog training devices that is often surrounded by controversy. Proponents of the choke collar point to its humane effectiveness, while critics say that the collar is more torture device than training tool. The truth is that what the collar becomes is largely dependent upon who is using it.

A properly fitted choke collar works by tightening around the dog's throat when the trainer pulls on the leash and then releasing pressure when the trainer does. If the collar is not put on correctly, however, the pressure will remain and the dog could truly choke to death. These collars are not meant for dogs that consistently pull at their leash or for inexperienced trainers. As is the case with head halters, the choke collar has the potential to cause injury to the dog's neck.

Electronic Collar

Just mention the option of an electronic dog collar and many dog owners (even some people with no pets at all) will look at you as if you have suggested training your dog with a stun gun.

The reality is that electronic collars can be a very humane way to train a dog. As with any other training device, however, whether or not it is used for purposes of cruelty is totally dependent upon the intentions and experience of the trainer.

The electronic collar works by allowing the trainer to give the dog small, electric shocks (via remote control) in order to modify its behavior. The intensity of the shock is left to the trainer. In general, the setting should be strong enough to make the dog's ears twitch. If the dog howls or yelps when the shock is delivered, then the setting is too high. Again, the electronic collar should only be used by experienced trainers.