Casey ranks at #164 with 639 entries, and our data marks it as gender-neutral, which puts it in a small club at this rank tier. Most pet names lean clearly male or female by the top 200; Casey, like Riley and Bailey, splits the difference and absorbs both.
The Irish surname-name lineage
Casey originated as an Irish surname (Ó Cathasaigh) and migrated to first-name use in the 19th century. The name carries the same surname-as-given-name texture that shaped Parker and Riley, which is part of why those three names often appear on the same shortlists.
One counter-reading: Casey also has a strong American sports register — Casey at the Bat, Casey Stengel, the cartoon trucker Casey Jones — and a subset of owners pick it for that nostalgia register rather than for the contemporary unisex appeal. Those Casey owners tend to skew older and pick the name for mid-sized mixed breeds rather than for the small companions where the unisex sound usually lands.
Why neutral works at this rank
Pet owners are generally less attached to gendered name conventions than baby namers are, which is why neutral names start to over-index on pet leaderboards relative to baby charts. Casey scans cleanly on either side and works equally well for a female terrier or a male retriever. The Casey baby name page shows the human chart, where the name peaked in the 1980s-90s and has softened since. For cross-shopping, Riley and Bailey occupy adjacent neutral slots on the leaderboard, and pet owners often pick between the three based on which one sounds best alongside their existing pets' names.