Dogs can clearly understand some human speech. I mean, the evidence is overwhelming. Some dogs even try to talk back. Dogs are also clearly capable of experiencing wide range of emotions and feelings just like a human. A dog is only separated from a human by a small bit of intelligence. A smarter dog is essentially a human a four legs. A dog is closer to a human than AGI will likely ever be, and deserve more rights as well, if for no other reason than the fact that they can clearly experience suffering.