Hi Christy, it does take a lot of work, who knows what he has been thru.
One thing with Reactivity is that the main thing is to work with the dog in a calm setting
where he can be controlled and maybe one other calm dog of a friend. Maybe the running is still a little much for him now. Watch the Reactivity videos. Three main takeaways
1) loose leash 2) NO CORRECTIONS, the dog corrects himself when you abruptly turn away walk 5/7 steps and return 3) You will notice in the videos for Reactivity that Robert does not use treats for these exercises. When ZEKE looks at you a gentle pet for 2 seconds and a calm Good Boy is all. Treats can excite and giving a treat may indicate to him that his behavior is being rewarded. Naturally there is somewhat more to it than this but these are the 3 basics.