Puggle is the widely used term for a Pug-Beagle hybrid — and as a pet name, it almost certainly reflects a dog of that specific mix being registered under their breed-descriptor as a name. The 41 registrations here are almost certainly Puggle dogs whose owners entered the breed type in the name field.
The Registry Artifact Angle
Mixed-breed dogs often get their informal breed name entered in the name field on licensing paperwork — especially when the breed type is the most distinctive thing about the animal and the owner hasn't settled on a personal name yet. Puggle the breed is well-known and widely used as an informal identifier. This entry almost certainly reflects that phenomenon rather than 41 dogs whose owners chose Puggle as a deliberate given name.
The Puggle as Breed
Puggle hybrids became popular in the early 2000s — Pug face softened by Beagle energy, typically resulting in a calmer temperament than either parent. If you have a Puggle mix, the Beagle breed page and browsing the full pet names index are good starting points for names that fit the personality type rather than the breed descriptor.
The Counter-Reading: Breed Names Make Poor Given Names
Using a breed name as a given name creates ongoing confusion — other owners will interpret it as a description rather than an address. A dog park full of "Puggles" being called as names would be chaotic. If the sound appeals, something like Pug or Percy gives you similar energy as a genuine name.