I saw an old movile about the dogs of Hollywood. In one informative clip, the narrator told the audience that the dog they were seeing going around in circles was doing so because of his trainer's silent sign language. Sure enough, we saw the trainer making circles with his hand and the dog was going around in circles, following suit.

So, that dog was reading a symbol, perhaps a symbol that others would interpret identically, and that dog was following the command showing that it understood the language.

Was that dog reading and was that dog reading words? I'm just askin'...