Dogs are getting it figured out. Had to get out my breaker stick. I havnt had to use that in a year or two but it happens with large/aggressive dog breeds. If they fight I gag em with the stick and wop em in the ribs a couple times. My red nose has always been a "special needs" dog. He was tethered for the first 3-4 years of his life,really out of shape And very aggressive to other dogs before I adopted him. He's too smart for his own good 90% of the time. And just needs a strong leader otherwise he gets stressed