Asklemmy

Yes and no. For one, many vegetarians and vegans would agree, so on some level, sure, that's a very defensible opinion. Secondly, North American sensibilities would call it a moral tragedy to sell cat or dog parts, so at some point we have to accept that what is and isn't okay to kill and consume is a question of cultural bias as opposed to moral truth.

Lastly, you can accept the state of the food chain without holding the belief that those at the top of it are "better" or "worth more". I don't eat beef because I am, in some universal truth way, worth more than a cow. I eat beef because I accept that in the chaos of existence, this is where the chips fell. I do not feel a sense of superiority for being able to do so. If you're going to get really strict about it, I'd define "murder" as the act of killing for the sake of killing, and say that killing for consumption and in some cases survival is different. But even then, I recognize that this is bias. If you want to call murder the act of taking a life, I've murdered a lot in my life, and I don't intend on stopping any time soon. Mosquitos won't squish themselves.

The question of intellect and understanding and the weight of these qualities in the value of a life is a dangerous road to wander down, so I like to keep in perspective that we're all meaningless specks in the grand scheme of the universe. Otherwise, the questions get even more challenging: to say a truly reprehensible thing, what happens when we replace the human or the animal in question with an exceptionally low functioning human being? Do we now say their life has little value because they can't contribute to society, they can't understand the state of their own existence, and in many cases they're not even capable of verbal communication? Does it become okay to choose to let them die, as in the original question? Are they suddenly fit for consumption as cattle? Or does the responsibility fall on the more capable to protect them?

Appraising and tiering life is an incredibly dangerous road to go down. You can choose any example of historical racism to see just how dangerous it gets. Life is life, and the strange differences between what's "okay" and what's not is luck more than anything else. Even as I consume a steak while my dog begs for the scraps, I believe it's important to keep an understanding of how we got here, else hubris allows us to justify basically any atrocity.