Scallywag, with a big dog you MUST learn to keep the nails trimmed. First time around ask a vet or groomer to show you how, and buy a can of styptic powder because soomer or later you may need it. This falls under the stuff you *have* to do for your pet. With a guillotine trimmer this should be no big deal. You can use a file or a Dremel tool (cordless) with a sanding/grinding wheel
too, but the dog may mind that noise
more than the clipper.
If you are worried about the floor despite keeping the nails down, add a piece of outdoor carpeting or astroturf to protect it, and another one draped over the tube where the dog boards.
There are dog life vests (try Cabellas or LLBean) for hunting dogs
, including a grab handle on the back, that work for these jobs. Once you look at the hunting/waterdog market instead of the pet store, you'll find good solutions.<G>