Let's suppose that we make contact with ET and mutual knowledge of our respective societies ensues.

Let’s suppose that we make contact with ET and mutual knowledge of our respective societies ensues. ET is millions of years more advanced than us and has forsaken the opportunity to improve upon natural evolution. ET has four legs, a face and a tail, managing to control technology by means other than touch.
Surely we would have a problem in that ET would soon learn what we have done to quadrupeds, how we have interfered with breeding and genetics of such things as dogs and cattle etc.
Furthermore, a majority of us regularly eat parts of animals that were bred for such a purpose. Surely a very advanced species would long ago have ceased this barbaric habit.

Yeah, so? The distances are so vast this hypothetical ET will never travel here, and any communications will take generations at least.

Let's suppose that we make contact with ET and mutual knowledge of our respective societies ensues. ET is millions of years more advanced than us and has forsaken the opportunity to improve upon natural evolution. ET has four legs, a face and a tail, managing to control technology by means other than touch. Surely we would have a problem in that ET would soon learn what we have done to quadrupeds, how we have interfered with breeding and genetics of such things as dogs and cattle etc. Furthermore, a majority of us regularly eat parts of animals that were bred for such a purpose. Surely a very advanced species would long ago have ceased this barbaric habit.
Wait, I've seen this movie before haven't I? Wait no, that was Planet of the Apes. You're talking about the sequel...Planet of the Cows.

It was a bit naughty to give Charlton Heston high billing in the first sequel. He did not want to do the film at all, then finally agreed to a tiny part in it near to the end. Of course it was all about the search for his character but the billing was almost fraudulant.