Hi Matthew. I have the same problem. I got 2 adult rescue dogs a year ago. They were street dogs abroad and then kept in kennels until we rescued them. Having 2 has made it more difficult as it's like double trouble. However we have moved on leaps and bounds. One of my dogs is still tempremental though. What sort of collar are you using? I use a half check, this enables me to "snap" the collar and distract them from their fixation - other dogs! If this doesn;t work then "tap" her with your foot on the side of her bum. It is not a kick but a touch to un-fixate her. When her ears start going up and she is looking around, do what the previous person said. Stop and get her calm before you move off. I run with my dogs, this helps with their fixation.

As for the electic collar, I will only use them as a last resort. A year later and I still won't give in to it. I work with a great behaviourist. I would prob advise against going to a regular trainer. I tried it and it is a very stressful for nervous dogs to be staring at each other. They are great for well balanced dogs with no issues.

check out the Dog Whisperer with Cesar Milan. His tactics have worked for me. Good luck and well done x