@boomerang,
Boomer, I have read that story. I guess it happened in Portland, Oregon and
the one dog (a small Pomeranian) was indeed a service dog, but the other
(a Rottweiler mix) was not, although its owner told the bus driver otherwise.
So the Rottweiler was the aggressor here and attacked the Pomeranian.
On the other hand, I can't see how a Pomeranian can be a service dog either...