Oh, I believe you. We had Patrol Dogs with us in our Rifle Company in Vietnam and they were big, mean and nobody screwed with them but their handler.
I owe my life to one who sensed a VC infiltrator who was approaching me in the total dark, drawn to the sounds of the radios next to me. The dog alerted and looked in the enemy's direction and his handler aimed a .45 in the direction he was looking and fired - hitting the VC in the side of the head and emptying his brain pan. We found him when it got light, just about 10 feet in front of me, face up.
Big believer in Patrol Dogs.
I remember you telling that story here. Thanks