[1]It is almost invariably false to describe any behaviour as unique to humans.
https://en.wikipedia.org/wiki/Animal_suicide
In light of this, some would argue that because we are better than them we are right to consume them or at the very least are not wrong for doing so. I disagree at least to a certain extent. Right and wrong have nothing to do with it to my mind. It has more to do with practicing what you want to be.
IF: you desire to be a 'good' person with compassion, empathy, patience, love, understanding ect.
THEN: You must practice those things. Humanbeings are not anymore good than they are evil, because humans are fluid. We can't ever be those things because the capacity for both is inherent to us, we can only practice them. People cannot be compassionate or empathetic. They can practice compassion and empathy though. Ultimately it is as Jungian psychology suggests. We believe what we act as. The human being's desire to be consistent and not suffer the great dissonance that comes with believing and acting in two different fashions is among your strongest of impulses. Nobody wants to live a lie.
[2]I would say that the existence of religion is just one of the more obvious refutations to this claim. The evidence is very strong that almost everybody strives to live a lie.
People have a self image that most are unable to live up to; and they resolve this by lying - to themselves and to others - pretty much constantly.
So all of this is to say:
1. You can only be as "good" as you consistently practice "good" things
2. Arguments that "Good" practices should be reserved for humans is an argument who's logical impetus comes from it being the natural prioritization
3. This natural prioritization is rendered moot by human's capacity for higher reasoning and the ability to override his natural impulses.
[3]Your premise that there is a universally agreed meaning to the word 'good' is deeply flawed, rendering your argument moot. Human are not in the least consistent; Nor do they prioritize other humans over non-human entities.
'Good' means looking out for your friends' interests. How we define and rank our friends is the main determinant of what therefore constitutes 'good' behaviour. If you own a pet dog, you are likely to embrace dogs as friends, and to be repulsed by those who see them as food.
If you are a member of a cannibal tribe, you regard humans form other tribes as 'not friends', and therefore as a viable food source. If you were a Roman citizen in the third century CE, You might afford 'friend' status to all other citizens, while considering slaves and the unconquered tribes outside the Empire as subhuman, and fair game for enslaving or killing for entertainment. If you were a Spanish Inquisitor, you would afford 'friend' status only to devout Catholics, and consider heresy to render a person unworthy of personhood - to the extent that it becomes the act of a good and noble person to torture them into recanting their heresies.
Empathy is the way we react to the people (and other living beings) that we choose to include in our tribe. Humans are good at inclusivity - people can be moved to tears by the death of a houseplant. They are also good at exclusivity; The same man who cries when his petunias die, can be perfectly happy working as a guard at a death camp.
Even inanimate objects can be accepted by humans as part of 'us', while most humans remain 'them'; If you scratch someone's car, they may well act to protect it as though it were their child that you were harming, and many would see nothing inconsistent in wanting to cause you serious injury in retaliation.
