Dude at rank 1391 is perhaps the most terminally casual name in the pet registry — a general-purpose form of masculine address applied to a specific dog with the specific intention of being as laid-back as possible. The Big Lebowski (1998) gave this word its permanent cultural shrine, but Dude as a dog name predates and extends beyond that reference.
The Lebowski Effect
The Dude — Jeff Bridges' Jeffrey Lebowski in Joel and Ethan Coen's 1998 film — is one of cinema's most beloved portraits of radical non-striving. "The Dude abides" is a philosophy entire communities have adopted. A dog named Dude by a Lebowski-aware owner is named after that philosophy: this dog doesn't try, and that's what makes it perfect. Mixed breeds and Labs with notably easygoing personalities are the primary carriers. Male dogs dominate heavily.
The Casual-Naming Category
Dude sits alongside Buddy, Pal, and Fella in the category of address-words-as-names. What unites them is the warmth of their casualness: names that imply a relationship rather than an identity. Buddy is the most popular version of this move; Dude is its more specifically masculine, slightly cooler cousin.
The Counter-Reading
Dude is aggressively non-aspirational. Owners who want that quality will find it delivers perfectly. Owners who discover later that they wanted something with more specificity will find there's no nickname path — you just call the dog Dude forever. That's either exactly right or quietly regrettable, and you won't know which until year three.