Carlos appears 81 times at rank 1340 on male pets — the Spanish and Portuguese form of Charles, from the Germanic Karl meaning man or free man. As a pet name, Carlos lands squarely in the human-name transfer category: owners naming their dog what they'd name a person they love.
Human Name as Pet Name
Carlos is among the most common given names in the Spanish-speaking world, and it enters the US pet registry primarily from households where it's a culturally natural first name. This is not an ironic or quirky naming choice — it's the same warm transfer that English-speaking owners make when they name dogs Jack, George, or Charlie. Chihuahuas and large friendly mixed breeds both appear in the registrations. The human name background is at /names/carlos.
Sound Profile
CAR-los is two crisp syllables with a strong opening and a clean close. It carries well across distance, doesn't blur into common commands, and has a natural informal shortened form in Carl that works as an additional call option when needed.
The Counter-Reading
Carlos as a pet name is completely invisible inside the communities where it's a common first name, and slightly unexpected outside them. Neither response is a problem. The name carries no pet-specific baggage. The only concern is that it provides no visual or personality cue about the specific animal, which purely descriptive names like Bear or Shadow do provide more naturally.