She might also have an illness that no medication can cure.
I would start by eliminating worms or mites/lice as a cause. Check for mites/lice around the vent. If you do not have them on a worming program, you should probably start with a round of piperazine, so the dieoff of the worms does not kill her, too. Later you can give ivermectin for other types of worms.
If she does not have mites/lice, and you already worm them, not sure there is much you can do, other than probiotics and basic supportive care. She does get enough protein, doesn't she?
I would start by eliminating worms or mites/lice as a cause. Check for mites/lice around the vent. If you do not have them on a worming program, you should probably start with a round of piperazine, so the dieoff of the worms does not kill her, too. Later you can give ivermectin for other types of worms.
If she does not have mites/lice, and you already worm them, not sure there is much you can do, other than probiotics and basic supportive care. She does get enough protein, doesn't she?