The quick (blood supply) in a short nail.
As the nail grows, the quick lengthens. If a cut is made into the quick, the nail will bleed profusely.
Trim here and the quick will begin to recede.
Trim or file a small portion of the nail every few days. The quick will continue to recede.
As the nail gets shorter, the quick gets shorter.
When kept short, the nail can be properly maintained without bleeding or discomfort to the pet.
A properly trimmed nail.