Here's a pattern that surprised me when I first ran the breed query: Luna is the #1 name for Domestic Shorthair cats and the #1 name for Labrador Retrievers in our NYC and Seattle pet dataset. She is also #1 for American Shorthairs and a top-10 across half the small-dog breeds we track. There is no other name in the top 10 that owns both the cat side and a major dog breed at once.
The cat that broke the pattern
Cats and dogs usually receive different names. Owners pick from different pools — cats get something celestial or mythological (Luna, Cleo, Stella), dogs get something punchy or sturdy (Max, Buddy, Cooper). That divide has held for decades. Luna is the first name in years where I can show you the line between the two pools dissolving in real-time data. Among Labrador Retrievers she narrowly beats Bella for the top spot. Among Domestic Shorthairs she is comfortably #1 with 67 entries — well ahead of the next name.
Some of this is the Harry Potter generation aging into pet ownership. Luna Lovegood arrived in Order of the Phoenix in 2003, and the readers who were ten or twelve then are now in their thirties and adopting their first companions. Some of it is the broader celestial-name wave that has been climbing across baby names too — Stella, Nova, Aurora. But what's specific to pets is that Luna doesn't carry any of the gendered weight those other names do. Owners use her on male cats fairly regularly, even though our data marks her as female-leaning.
Why two soft syllables actually work
Conventional dog-naming advice would push you away from Luna on phonetic grounds — no hard consonants, no clipped ending, vowels everywhere. The advice is wrong here, and the data shows why. Two-syllable names with a clear stress pattern (LU-na) are easier for dogs to distinguish from environmental noise than purely short names, because the second syllable confirms the first. "Lu" alone is ambiguous. "Luna" is unmistakable. The same logic explains why Bella works.
For cats, none of this matters. Cats respond to pitch and tone, not phoneme structure. Owners pick Luna because the name is beautiful to say, full stop. That's the rule for cat names that the dog-training books refuse to acknowledge: aesthetics is the engineering criterion.
Luna the baby name is also climbing
The pet trend isn't happening in isolation. Luna passed Sophia for the SSA top 10 in girls' names a few years ago. The baby name page shows the climb clearly — same window, similar slope. What you're seeing across both datasets is one of the cleanest cultural-wave names of the past decade, where the human and animal versions are reinforcing each other instead of competing.