Yeah just don’t bother. They are arguing by the definition of veganism, which holds no moral weight in argument. Saying it is wrong to eat meat “because meat is a killed animal” doesn’t mean much. I could say that it is wrong to look at the sky because “the sky is blue.” These statements hold no moral relevance. The reason it is wrong to cause unnecessary suffering to an animal (most animals) is because they have the capacity to experience suffering. Suffering matters. No one cares if you break a rock open because it can’t feel pain. We care when you slit a cows throat open because the cow CAN feel pain.

These vegans who say “because it is an animal” don’t have a consistent set of morals. Many of these types of vegans say that we shouldn’t consume or buy honey because bees can suffer. But bees aren’t animals. They are insects. So what are we valuing here? The fact that something is an animal or the fact that something can feel pain?

Pain is morally relevant. Saying “it is an animal” is only relevant when the animal in question can experience suffering.