Nail trimming should be done every 2 or 3 months. Check your pup or dog often to see at what rate their nails are growing. Often, if you don't clip the nails often enough, the clickety-clack sound of them on hard flooring when your Yorkie walks will remind you. And if you continue to ignore this grooming need, they can become ingrown which will cause quite a bit of discomfort for your dog.
An owner may do this themselves or opt for a dog groomer to do this. If doing this at home, it is important to use quality pet nail trimming tools. The cut should be fast and easy, as most dogs do not stay very still while having this done. A good alternative to clipping is a grinder, which (if it's a good one) will quickly and relatively quietly mechanically file the nails.
One of the biggest worries of those who try to trim their Yorkie's nails at home is the element of cutting to low and cutting the "quick" of the nail. The quick is a vein that runs down the center of each nail. If cut, there will be quite a bit of bleeding. If you do clip the nails, do a little bit at a time, taking a look each time you trim a piece. As you slowly remove small pieces, you will eventually see a gray or pinkish color oval of color in the nail. This is your sign to stop cutting.
There are solutions, such as a styptic pencil or silver nitrate that you can obtain, so that if a mistake is made, it will help to stop the dog's nail from bleeding.
Trimming is easier if done right after bath time, when the dog's nails are wet. And grinder can be done at any time.