Just a question did you supplement niacin with your pekins ?
Add extra nutritional yeast to the feed ?
I have a pekin myself and she hasn’t given me any issues and none of her offspring have issues
But I do add nutritional yeast as babies 1 tbs to 1 cup feed and as adults I sprinkle it on the feed a few times a week
Through winter I’m adding it to the feed daily
Pekins usually need the extra niacin more then what the feed provides
So if you are not doing this already
You could try and see if it helps
Also try vitamin B complex 1 ml over a treat or by syringe if they are really struggling do this for a few weeks as well as the nutritional yeast
You can’t overdose the niacin they will release why the body doesn’t need
Hood this helps