Thanks for the additional information. It is helpful.
I am personally not a fan of the head collar or halti. It can lead to injury to the neck. A better choice is the harness where the leash clip is on the chest. Instead of jerking a dog's head around, the whole body is turned back toward the owner when walking.
However, let me go over the instructions I use for my clients to teach a dog to walk on a leash properly. I've found it works on even the most stubborn dogs. I also want to point out that when you shorten the leash, you are transmitting the fact that you are worried. The dog doesn't know why you are worried. They tend to automatically think it is the other dog that you are worried about and not that she is going to go after the other dog.
If your dog is pulling while walking then a little retraining is in order. It's a matter of getting your dog to want to come with you regardless of the leash being attached. You will get multiple answers depending on whom you talk to as opinions differ on the best method to solve this problem. I personally believe in establishing control over the dog with training. I use a chain collar for training purposes. For strong stubborn dogs, some trainers recommend a prong collar.
Number one, put your dog on a leash before leaving the house. Make your dog sit or lie down before leaving. You walk out first and the dog should follow you out. With a proper walk, the dog should be right at your side or slightly behind. You dog should be paying attention to you, frequently glancing at you to be sure you haven't changed your mind about where you are going. I will be using the word correction. A correction will indicate a short quick tug and release of the leash. It is meant to remind the dog that she is supposed to be paying attention to you. Initially, keep training sessions short and where there will be minimal distractions even if it is just in your yard. A walk should be fast paced and not a stop and start exercise. The dog should not be investigating, sniffing or socializing on the walk. Walk to a destination and allow the dog some time at the destination to do those things.
I use a food and praise reward system. I use almost paper think pieces of hot dog as the oil from them coats your hand and keeps the smell on your hand. Let the dog smell the treat in your closed hand. This gives your dog motivation to be by your side. She should be happy to follow your hand around the yard. Keep your leash short, but without pressure on it. If the dog starts moving away, a correction toward you should be made. Give her a treat every once in a while initially so she understands walking by your side gets her treats. Try to time it so it is before she gets distracted. If she starts to glance elsewhere, give a correction and tempt her with sight of the treat. When she is back to paying attention, reward her with the treat in a low calm "good girl". No excitement to your voice as you want her calm. Repeat when you think her attention is shifting. As she gets better at paying attention to you and your "smelly hand", make corrections giving more praise and less treats. Before you know it, your dog will be walking right next to you all the time, with or without treats. When you stop, praise your dog with your voice or a few pats to let your dog know how good she has done. You can train her to sit or lay down when you stop if you want as well. This helps prevent her trying to run off if you stop to talk to someone.
Once your dog is pretty much always walking at your side, you will want to make a correction any time she stops paying attention to you. For instance, they are looking at a cat in a yard, give a correction so they look at you. if he is busy looking ahead and hasn't glanced at you for awhile, give a correction and reverse your direction. Do not stop and wait for the dog, just a quick correction and reverse and walk. They learn to keep an eye on you as well as on what else is going on. Try an be confident during these training sessions. Try not to look down at your dog but more out of the corner of your eye. Act like you are paying attention to the scenery. It sounds strange, but it does work.
Once your dog is doing well in the yard, try adding a few distractions such as family in the yard, then progress to another dog around continuing to correct if she even looks like she is going to glance at the other dog. If you wait till she is already distracted, it is too late. You have to catch her before she focuses on the other animal or person. It is a lot of work and takes lots of practice but it does work.
Once you are at this point start walking past problem areas keeping all I have mentioned in mind. Keep the treats in your hand and give them to her as you are walking past IF she is still paying attention to you and not lunging at the other dog. If she does lunge, reverse direction, walk a little and try again. Start this training with her alone and not with the other dog.
Now there is a site that discusses another method called BAT that may help in this situation as well. Read more on this here:
Once she is much better on the walk, then add your other dog. It is likely you might need to reinforce her training more when you first add your second dog, but this part should go pretty quickly as she just needs a little reinforcement of what she has already learned.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer.