Interestingly, there’s a “Judge John Deed” episode that covers this quite nicely (not sure of the title) where a boy needs to have an organ replacement from an animal, and refuses it on the grounds of being a vegan, but his parents want to force him to take the transplant against his will. Won’t spoil it except to say that it gets ethically… Messy.

But the fact that we’ve gone from that to actively discussing whether parents should be able to consent to actually killing their child (because that’s what it comes down to, in the end) is quite frightening, imho…