Because it is more comfortable for the dog and you can get the nails shorter and smoother (which is nicer for you). Many professionals agree that this is actually a much more comfortable method of maintaining nails than clipping them because it does not pinch or hurt the quick. The quick is sensitive living flesh inside your dog’s nail. If you use a guillotine style, then the nail is pushed hard against the immovable blunt metal while the blade cuts in from one side. If you use the scissors-style, then two blades squeeze in from either side of the nail. The harder the nail, the more pressure you must apply. This can be very uncomfortable for the dog. In order to get the nails back, you keep doing a series of small clips and try not to hit the quick. As a result, you often stop short of where you could go, if you were using a Dremel. When done properly, there is no squeezing or pressure on the quick with the Dremel. Further, you can see “inside” the nail as you gradually grind back to the quick. So, you can judge when you’re getting close to nicking it and stop in time. With the Dremel, you can also grind off all around the quick so that it recedes faster and you can get even shorter nails. The closer you can get to the quick, the more you can force it to recede and the more quickly it will recede. Finally, you can grind off all the corners and rough edges leaving nice soft nails that don’t gouge nearly so much when your dog paws you for affection.
How to Use a Dremel to Trim a Dog’s Nails
Do not use the various grinding stones that come with the dremel because they get too hot for the dog’s nails and can hurt the dog! Please do not use any of these. There are some great diamond bits that are easy to use, removes excess nail, and provides a nice smooth finish. These bits are more expensive, but last forever.
Secure your dog. Every dog reacts differently to the sound and sensation created by a dremel, and until your dog becomes used to it, he may struggle or run away. A grooming table with an overhead arm to which you can attach the leash is optimal, but you can recruit an assistant to help hold your dog or you can tie your dog’s leash to a post or other sturdy object.
Fit the dremel with a cylindrical bit or an inverted bit. The inverted bit with a hollow-tip works very well because your dog’s nail fits right inside the hollow area. Check hobby stores for a hollow-tip bit or ask your hardware store about special-ordering one. The cylindrical bit has a flat circular tip that offers safety and control. Avoid using a very small bit or a pointed bit that can slip and injure the dog.
Introduce your dog to the dremel slowly. Let him sniff it while it is turned off, then turn it on and off to allow him to hear the sound it makes. If your dog is frightened by the dremel, the first few trimming sessions should be very brief.
Hold your dog’s paw firmly, but don’t squeeze it. Push gently on the top of the dog’s paw, just above one nail, to separate that nail from the rest. This pressure will cause the nail to extend slightly. If your dog has furry paws, smooth the fur back and away from the nail or trim the fur away before using the dremel. If the dremel catches in long fur, it can injure your dog’s paw.
Touch the spinning dremel bit to the tip of your dog’s nail, using very little pressure. The momentum of the dremel will grind away the tip of the nail, and using pressure may cause the tip to slip and injure your dog.
Move the spinning tip lightly around the end of the dog’s nail, taking care not to place the bit too close to the skin or fur. Keep the hand that is holding the dremel moving at all times to reduce the risk of slipping.
Speak reassuringly to your dog and take a break after each nail, offering your dog a treat or praise for being so good before continuing. A few short sessions are less traumatic than one long session. Once your dog is used to this method of nail trimming, you can do more nails before stopping for a break.
Here is a link to a great demonstration on introducing your dog to the dremel: http://www.doberdawn.com/doberdawn/dremel.html
And some links to the diamond bits:
http://www.whitmansharpening.com/Diamagroove.html (this in my opinion is the Cadillac of the diamond bits)
http://groomwise.typepad.com/grooming_smarter/2016/10/dremelling-nails-with-diamond-bits.html (also demonstrates using the diamond bit, and you can order direct from her.)