I have hardwood floors and four dogs. First, area rugs and long rugs down hallways will not only help protect the floors (as will an extra layer of whatever sealer is on the floor like we have polyeurathane and my husband put down two extra coats in the high dog traffic areas) but also dampen the sound and help prevent skidding (watch a couple dogs and a cat decide to start racing through a house of hardwood floors!) Second, keep the dog’s nail clipped short. Your vet or a groomer can help you do this. If the nails are long, gradual, weekly trimming will help cause the "quick" in the nail to receed and eventually the nails can be shortened. I keep nails at least to the point where if the dog is standing on the floor, the nails easily clear it without touching. This will help cut down on the noise as well.