Cutting your pets nails always makes one uneasy. When the nail is BLACK it is evan more difficult to see where the vein in the nail is. In a white nail you can see through the side where the pink quick is before you cut. You don't want to hurt your pet or make him/her uneasy. If you accidentally cut through the vein it will bleed. Always have styptic powder on hand just incase. Your dog will not bleed to death. Sometimes an accident will happen when they are outside and a toenail will get broke off or even worse ripped out. A TRICK to cutting the nails for a novice is to examine the underside of the nail. You will see the nail is thicker at the base where it comes out of the toe. As you get to the tip on some it narrows to a thin point. You are always safe to cut this off. Make sure to hold the toe and extend the nail outward by mild pressure on the toe itself. Make the cut FAST. A slow cut can split the nail. ( more like crushing it). Then look at the end of the cut. On a BLACK nail it will be white in the center of the cut. If you see a small black dot in the center you are close to the quick (vein). If it is solid white you can make another safe cut. You want your cut to angle back on the nail, not straight down. The quick runs closer to the bottom side of the nail than the top, so by tipping back the top more, a little at a time you will be able to watch for the little black dot to appear. You will learn in time how far you can go. You will be able to just run your finger under the nail and where it curves and cut. You want to get close to the quick as this will help it recede farther back in the nail. Taking your dog for a walk or run on a cement surface will wear off and sharp edges. Alot of dogs don't like files, and it's relaxing for him/her to have fun with a good game catch when it's all over.A good walk on CEMENT  often will keep a pets nails in good shape by wearing them down naturally. OUR PROBLEM is most are dogs have the couch potato life with carpeting or grass. Neither will wear down their nails. Now, sometimes the back nails will be shorter than the front nails, this is because they are the driving force for walking. Sometimes the can only be tipped slightly at an angle back on the tops of the tip. If you accidentally cut the quick, just take a little blood stop( styptic ) on your finger and hold it on the nail tip with pressure for a few seconds. If it is still seeping, or bleeding try it again. Hold in on the cut with pressure. If they are a crazy run around nut they sometimes knock out the packing and you may have to do it again. You don't need alot of powder. If they have long hair, make sure it is pushed away from the bleeding nail so you can cover the cut surface. Don' worry, you will all survive. It sounds worse than it is. By keeping you pets nails in shape you are helping him aviod painful foot and leg trouble. Think if you had to walk on your nails ---OUCH! GO FOR IT