Definitely. While working on my M.A. in Spanish at UWM, I took a course on the history of the Spanish language. One of the first things I learned was that the Romance languages (including Spanish, of course) evolved from Vulgar Latin. That’s why so much of the their vocabulary resembles that of V.L.
Why would anyone name their dog “But”? N.B. In Spanish “pero” means “but” and “perro” means “dog”.