Bob,
it's one of the reasons I shoot hand-held -- it's the only way to get that really low angle. I agree, it's a point of view most show photographers never capture because they'd prefer to shoot off of a tripod but I think it makes the "big" dogs look even more magnificent. I like to shoot Rotties, Danes and Bullmastiffs from this low angle.
For other breeds, like Dobes, Goldens, Labs, etc., I shoot a bit higher by sitting on the floor. No wonder my legs and butt hurt after a show

!
Thanks for the Rowdy compliment. He's resting up now that the shows are over. Last evening we took a walk on our nature trail and spotted 5 white-tailed deer off in the underbrush. He just sat next to me and we watched them hop off with their tails waving at us. I think he's going to enjoy his "retirement".
Jim