Kenny,
nice, simple set-up but it won't quite work for Great Danes or group shots with a judge, handler, owner and co-owner.

What do you do for those types of shots where the background isn't wide enough to cover the subject(s)?

I use 12' wide by 10' high backdrops for my non-ring formals and sometimes even they aren't wide enough (I end up cloning in more backdrop). Of course, I shoot a lot of large-breed Specialties and All Breed shows with a lot of big dogs. For the Toy Specialties I shoot, your set-up is very similar to what I use with 400 W/S Alien Bees bounced off of silver umbrellas. At shows, I do very few dog-only photos.

Thanks for sharing,

Jim