Pedro appears 82 times at rank 1332, almost entirely on male pets. It's the Spanish and Portuguese form of Peter — from the Greek Petros meaning rock — and it appears in American pet registries primarily among Latino owners who bring their own cultural naming conventions to the licensing form.
Cultural Transfer in Action
Pedro is a common human name across Latin America, Spain, and Portugal, and when owners in those communities name a dog Pedro, they're often making the same kind of affectionate human-name transfer that English-speaking owners make with names like Jack, Charlie, or George. The cultural register isn't ironic or quirky — it's direct and warm. Chihuahuas and mixed-breed dogs dominate the registrations at this level of the registry.
Pop-Culture Threads
Pedro has accumulated pop-culture resonance across multiple decades: Napoleon Dynamite's Pedro (2004), Pedro Almodóvar, Pedro Pascal's current cultural moment. None of these are why most dogs are named Pedro, but they give the name broader recognizability for non-Spanish-speaking audiences. The human name's background is at /names/pedro.
The Counter-Reading
Pedro doesn't carry any pet-specific connotation — it's purely a human name on an animal. For owners outside the cultural context where Pedro is a natural first name, it can read as slightly unexpected, which some find charming. For owners inside that context, it's simply a name that sounds right.