I just want to point out that something being "natural" does not inherently make it ok. Killing other creatures of the same species (murder) is "natural", rape is "natural", stealing is "natural".

The entire point of ethics/morality is to distinguish between the natural things which we find good, and the natural things we find bad and want ourselves and others to stop doing.

My point being that if you want to defend eating meat as morally ok, you should do so without the "appeal to nature".

Murder isn't something that can only be done to people.

humans are animals

I suspect they might be referring to the thing they replied to, the sentiment "I love murder"

Are you comparing a handful of dead people to several million animals getting brutally killed per day? The biggest difference between the holocaust and animal agriculture is the intent to exterminate the entire group for good.