Oh please, when the dog is sitting there gazing at you with huge soulful eyes he's asking for something.
Actually, animals do. When my cats food bowl is empty, he circles my feet meowing ... going to the empty dish ... then back around my feet meowing. I would guess that means "May I have more food please?"
There are many ways to communicate besides language. People and animals can both make their needs known without speaking a word. Yes, if a person can't speak to tell you they're hungry, they have to use other means. I care for people on ventilators (who cannot speak) ... and sometimes they are unable to write ... and yet, they are still able to make their needs known.