Rudy ranks at #185 with 576 entries, and the name carries the particular friendly-everydog register that Hollywood has been training audiences to recognize for decades. Rudy is shorthand for an underdog with heart, and the name does that work whether or not the owner is conscious of it.
The underdog-name lineage
The 1993 film Rudy about Notre Dame walk-on Rudy Ruettiger gave the name its modern mainstream texture, and the film has become a cultural reference point that pet owners default to without explicitly meaning to. Compare with Buddy, which works the same friendly-everydog register a few tiers higher.
One counter-reading: a smaller share of Rudy pet owners are drawing from the German Rudolf or Rudolph diminutive register — particularly in December, where the Rudolph the Red-Nosed Reindeer association becomes briefly relevant. Holiday adoptions named Rudy or Rudolph are a real but small subset, usually for red-coated or red-nosed pets where the visual register works.
Where the name lands by breed
Rudy over-indexes on mid-sized mixed breeds, retrievers, and family-dog-coded breeds where the friendly register matches. Cats also use the name at moderate rates, particularly for orange tabby cats where the warm register fits visually. The two-syllable trochaic shape (ROO-dee) recalls cleanly and projects well outdoors, which makes it a practical pick for active dogs as well as a warm one for indoor pets. The Rudy baby name page shows the human chart, where the name has held a stable but quiet SSA position since the early 2000s. Owners cross-shopping similar friendly-everydog names usually consider Buddy and Wally alongside Rudy before settling.