In all seriousness, if you go to an outing with larger YC's, you will see ALL kinds and breeds of dogs along on the member outings. Granted most are smaller, 40-50 lbs or less, 15-30 like Winston pictured above is probably the most common in my YC. BUT, we do have a couple with a pit bull, a lab or 2 or three, golden retrievers etc on the larger size too.
I would agree that most properly trained dogs will not jump overboard when moving.
Choose what you think will work, a PFD for the dog should be included, as it is easier to bring them up via boat hook or equal when the PFD has a loop on the top. issue 2 in 2008 DIY Boat owner mag has a good article on hound PFDs and how they fit different dogs etc.
She drives me boat,
I drives me dinghy!