I... wish I were joking, but a few years ago, a group of linguists in Europe who needed better hobbies and more fulfilling connections with other humans created a research project called "Melody in Human-Cat Communication", or "Meowsic" for short. Essentially, they studied how cat sounds are nearly always used to communicate with humans rather than other cats - especially meows (hisses, of course, have universal application). Among other things, this project recorded cats from all over the world and determined that cat sounds do have regional "accents" based off of the sounds that they hear coming from their humans. Dogs, on the other hand, do bark and make most of their noises for the benefit of other dogs, so as a result their linguistic variation did not vary.