Assuming anything about your dog is probably a mistake.
(Same goes for most people.)
When Gomer arrived, he was a manic, frenzied force, racing around my kitchen on his noisy toenails, tongue hanging out, pausing only to leap on any persons who happened by.
We took him for a walk with Frankie and he lunged at him over and over, snarling and yipping and frothing at the mouth. And when he was on his own, he attacked the leash itself.
I tried to contain him in the kitchen, and he leaped over the gate to follow me.