Many people find that a headcollar helps with pulling dogs.  I've found that some dogs get on with them and some dogs don't.  I've never used one on Jamie because he simply doesn't like them but Sasha doesn't seem to care one way or another.  I never use them just for going for a walk but at agility shows and at training classes they can be helpful in controlling a boisterous dog.

Dogs with short noses such as boxers don't get on so well with a headcollar and I've seen a rottweiler pull backwards out of the headcollar and walk off!  With dogs like this you may be better off with a harness.  When you first use a headcollar you need to teach your dog how to wear it and how to walk in it.  Try the headcollar on very briefly and praise the dog.  Give a tasty titbit and have a little game.  That was fun for the dog.  Now try it again. If the headcollar is adjustable  make a quick note of the bits that need adjusting and take it off again.  Praise the dog and have another little game.  Adjust the headcollar  and carry on with the training.

Once the dog is happy to wear something round it's face you can leave it on a bit longer and give praise and titbits.  When you and the dog are perfectly happy with all the adjustments and the general fit of the headcollar you can try walking a little way to see how you get on.  In the picture on the right Sasha is wearing a homemade headcollar.  She poses quite comfortably but she'd rather be going for a walk in it!

Don't ever force your dog or frighten your dog where headcollar's are concerned.  Gentle training is much easier and you and your dog will be much happier. 

Headcollars come in all shapes and sizes.  Some are the figure of eight type like the Gencon and the mountain rope ones shown below.  They are all in one headcollars and leads.  Some people have stitched a stop behind the metal ring to prevent it from tightening too much.

Sasha sometimes wears a Gencon like the one above on the left at training classes and at shows but I'm careful to stop it from tightening too much.  If it does tighten then it's time for me to take her away from the action to calm down a bit.

Here are some of the different types of headcollar available from the Agility Bits Doggie Shop.
Halti Canny Collar Dogmatic Martingale