Justin appears 68 times at rank 1,538 — a thoroughly human name applied to pets, which puts it in the same category as Dave, Kevin, and Brian. The name peaked for human babies in the early 1980s, making most Justin-owners now in prime pet-adopting age, which largely explains its registry presence.
The Generational Echo
Justin was a top-10 baby name from the mid-1970s through the mid-1990s. Adults who grew up with multiple Justins in every classroom are now old enough to name pets, and a meaningful percentage of them named their dog after themselves, a childhood friend, or simply because the name felt familiar and warm. This generational echo pattern is visible across multiple human names that appear in pet registries at this rank tier.
Justin Bieber Territory
Justin Bieber's global presence kept the name current through the 2010s in a way that complicates the pure nostalgia reading. A pet named Justin after 2010 could be a sincere Bieber fan, someone making a joke, or someone who genuinely just liked the name. The human name at /names/justin shows the decline clearly — which makes it more distinctive and less expected as a pet name going forward. Compare with Drake for similar pop-artist-name territory.
Does It Work as a Call Name?
JUS-tin is crisp and two syllables — it calls cleanly. Most Labrador Retrievers named Justin are probably perfectly happy with the name. The dog doesn't know the SSA trend data.