R is for Rottweiler
(That's a real winner
@Saskia, and brought me back some lovely memories:
One of my ruby Cavaliers fell in love with a little Duck Toller called Petra, when I was taking my two little pups to puppy training classes. It was reciprocated which was a "very bad thing!" because while we were there as much for socialisation as obedience training as such, Petra was starting her training to be a gun dog so wasn't really allowed to be distracted by boyfriends...
It was a life long attraction for these two little red dogs because if ever they saw each other afterwards they were overcome with doggy joy!)