NoraBrooks

I have 2 young dogs that I am trying to teach how to walk together. One is a bullmastiff/pitt mix who's almost 2. The other is a boxer mix who is about 20 months. They both walk relatively well on leash. When I have tried to walk them together, I use a splitter which makes it easier, but...You would think they were competing to be on a dog-sled team. They pull so hard it is all I can do to hold them back. If a something like a dog/person/squirrel catches their attention, I turn around and pull them the other direction. I have used treats, praise, etc. How can I train them to walk well together?