Absolutely do not use an electric collar on a dog exhibiting reactivity. This is never an appropriate training method for a reactive dog.
Please consult a trainer. The money spent on a good trainer can prevent a lot of psychological damage.
Ah, ok. I'm not very familiar with that kind of collar.X2 on the ecollar!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! DO NOT USE AN E COLLAR TO CORRECT THIS BEHAVIOUR
I would bring the dog to a trainer, but be careful which one you choose!