Lola gets so "locked in" to the cat that she actually refuses any treat, including raw little pieces of steak!
I have to get her attention back to me before this lock in, which is what we are working on. hopefully some progress! we will see.
She is responding to a recall and/or leave it (she knows both commands) usually.
Our last dog had a similar, but a little different obsession that we worked on a lot - his was mostly with another GSD that he knew and was in our social group of GSD owners. Unfortunately they "hated" each other and always wanted to fight. we did finally get both to realize they had to at least tolerate each other from a distance (never too close so there is hope for Lola!