G-dammit people, don't let your aggressive dogs roam free and then blame ME when they attack my dog and he responds! Yes, I zap him (which hurts at high voltage), which stops the interaction, and yes, he is on a leash, insured, and fully vetted and tagged. Your dogs are not.
I'm f-ing sick of hearing you puzzle over why your dogs' electronic collars don't work. They just don't; your dogs are aggressive; you're at fault.
I feel awful when there are episodes like this, yet I hear from others that they have trouble with your pets, too. So, PLEASE, do something, already, dammit!
And your yard looks like isht, too.