Has anyone tried these? (Soft Claws)
http://www.softclaws.net
I've ordered a set for my 55 lb dog and am going to give them a try before installing a new hardwood floor. I used them on one of our cats and they worked great (to avoid ripping up furniture). The vinyl is somewhere between rubber and plactic in texture, but smooth and only slightly flexible. You trim the tip of the nail, fill the soft claw with the glue they provide (smells identical to super glue), slide it over the animals nail and hold it there for a few seconds. Most of them stayed on the cat for a couple of months.
Since the cat/dogs nail grows in a cone shape and the outer layer eventually sheds, the soft claw will just fall off with it at that time.
For the dog, I have to wonder if he's gonna chew it off. I'll reply back and see how it goes.
There is a link to testimonials on the site below. A number of them mention that it avoids scratches on hardwood floors:
http://www.softclaws.net/testimonials.asp