It's left me with a moral quandary.
The vet wants to kill her. Myxo is an almost certain death sentence, and a nasty one, too. The survival rate for normal myxo is (or was) <5%. However, it may not be normal myxo. There's a few less-lethal varieties around now, and one of them causes lumps on the rabbit's face and ears. To quote:
http://www.rspcasa.org.au/myxomatosis/Another rare symptom (in a much less common strain) causes a lower grade chronic disease and lower rate of fatal outcomes. It can result in lumps developing around the ears and face that will resolve on their own. These lumps are named myxomas and the disease virus was named after this lesion.
She has lumps like this, they look like mosquito bites, and she's still reasonably active and eating. But this variant is described as rare (so it's unlikely she actually has it), and it doesn't say what the death rate is.
I mean, I could kill her, but this is the only life she has. There's no reincarnation, and she doesn't get to start a new game and try again. Or I could give her her chance at survival, but that could sentence her to needless suffering and a cruel death.
I'm inclined to give her her chance to pull through, we wouldn't countenance killing people if they had a diceroll shot, but I might just be being a coward, unwilling to make the hard choice and dressing it up in excuses.