Kasey sits at rank 1671 with 61 female-leaning pet registry records. It's a phonetic respelling of Casey, the Irish surname turned given name from the Gaelic Cathasaigh meaning "vigilant" or "watchful," and the K-spelling is probably partly a paperwork artifact of owners who wrote the name as they heard it rather than in any standardized form.
Casey vs. Kasey — The Spelling Question
Casey is the dominant spelling on the human side, but in pet naming, alternate spellings appear with more frequency because there's no school enrollment or legal document to standardize against. Kasey, Kacey, and Kaci all appear in registry data and all represent the same name. The Casey entry and the Kasey entry are drawing from the same pool of owners. Combined, the name has more presence in the registry than either spelling alone suggests.
Sound and Gender Drift
Casey/Kasey has been drifting female in US naming since the 1990s, following the broader pattern of -ey ending names moving toward female association. On pets, the K-spelling skews female slightly more than the C-spelling. It's a two-syllable name with a clean, bright sound — easy to call, easy to remember. Border Collies and Australian Shepherds get active, alert-sounding names like Kasey with some frequency.
The Counter-Read
The K-spelling is a minor variant of a mainstream name. Owners who want something distinct should know that Casey and all its variants combined are not rare in the registry — but they're not oversaturated either, which is a comfortable place to land.