Trimming your Chow and Shih Tzu Puppy's nails can be a very scary task, depending on your approach. There is a nerve and blood supply in the Quip (middle of the nail) . If cutting too deep, the Quip will be hit and the nail will bleed and cause pain for your puppy. Always try to remain calm and hold the nail firm so you can see what you are cutting, because if you are stressed, your puppy will also be stressed.
Dremmel tools are sometimes also used but the heat and noise can scare a puppy and if it's a long haired breed, it can wrap around and pull the puppy's hair.