Humans, unlike the animals that human keep as pets, are capable of complex speech, so I'd bet that treats would be marketed towards the humans themselves, so that the humans then push their keeper to buy those treats. Sorta like how lots of ads for toys are marketed towards kids, because advertising works better on them and then they'll go and push their parents to buy them.
If we are separated from our parents shortly after birth, and grow up in isolation from other humans - then we would not learn to talk anyway. Note that that's what happens with most pets that humans keep. Maybe we get to walk past some other humans in the park a couple of times a week, but that's it.