Hi Dave,
Indeed, I have wondered about similar issues!
Not so much about if dogs can become enlightnened (do they even care?) but about what their perception of life is. In general, to me, animals appear more at ease with the flow of life than humans. They don't resist as much. They are much more accpeting of what it than general human beings. I don't know why this is, maybe animals have no or little karma? Maybe different animals have different aims spiritually? As we, when we die, will dissolve back into the earth and become part of all that is, we are also the animals, plants, etc. So, all is one. The difference, to me, between humnas in general and animals is that we resist more, we strive to achieve something, be it enlightenment or anything else. I don't know why. I guess it's god's will, whoever god may be.