Carly ranks #812 with 144 registrations, female-leaning. The name is the standard diminutive of Carla or Caroline, and on a pet license it usually marks the household-intimacy choice: families who wanted the affectionate form on the paperwork rather than a more formal alternative.
The 1970s diminutive register
Carly belongs to a cohort of -y feminine diminutives (Sandy, Wendy, Mandy) that peaked for human use in the 1970s thanks to singer Carly Simon and the soft-rock era she anchored. On pet registries, those same names cycle a generation later: parents who grew up with the sound now use it for the family dog. The human Carly page shows the human peak in the late 1980s.
Sound and call-name fit
Two syllables, front-stressed (CAR-lee), open R into a soft -y ending. The shape carries well at park distance and tolerates a wide range of household intonations. Carly lands without strong breed concentration but skews toward medium companion dogs, golden retrievers, and friendly mixes where the warm sound matches the temperament.
The owner-type read
The honest read is that Carly is a comfort-zone name. Households picking it tend to want a feminine, familiar, non-trendy choice that won't read as either too cute or too edgy in twenty years. If the goal is the same warmth with less 1970s baggage, Cali and Carmen sit close.