dog, guard versus dog, riding
The question about what types are these dogs from the core rulebook was answered for me from the Players Companion Adventurers Armory after finding this thread in which it wasn't quite addressed.
dog, guard is a small dog (as defined in the bestiary), though its price is justified as trained for combat as in the handle animal skill.
dog, riding is a medium dog (as defined in the bestiary), trained for carrying small riders.
And the skills for handle animal also now says that you can change a medium riding dog into a medium combat dog (though it will then forget how to be a riding dog) so you could train larger dogs for combat, though the prices listed in the core rulebook are as above:- dog, guard is a small dog trained for combat, and a dog, riding is a medium dog trained for riding.
