It's an interesting question. On one hand we don't worry about this much with animals, the most advanced of which we know have personalities, moods, etc (Pigs, for instance). They really only seem to lack the language and higher-order reasoning skills. But where's the line?
We do worry much more about animal well-being than we worry about our "lumps of metal" (as a cousin comment fittingly put it). As we should, and generally I think we should worry much more about animal welfare. I find concerns for AI system welfare voiced by people like Thomas Metzinger wildly misguided.
And while they don't have language like we do, dogs can understand basic commands and they aren't even the smartest animals.