Rhode Island Reds Losing Tail Feathers and White butts

First things first, the hens in question are about 13 months old and both Rhode Island reds. We live in Minnesota and they've been laying through the winter. About a week ago we found a lot of blood in the coop, but no visible injuries on either chicken. They both have white crud on their butt feathers, but it's not goopy, more like dried poop than anything which they didn't have in the warmer months. Now one chicken is losing a lot of her tail feathers, the other one seems fine. She doesn't have any skin showing, so we haven't tried any of the things to stop picking. They also both stopped laying, which, alone wouldn't be cause for concern, but with everything else this chicken momma is worried!
We have been feeding yogurt with applesauce and mealworms just in case of vent gleet, but the feathers aren't goopy or glued down, and with the weather we don't want to cut their feathers or bathe them (we have two big dogs and not a lot of space inside, don't want them to get stressed inside and wet).
Could they be molting? We were under the impression that they were still too young for that.
Anything else we should be trying?

What are you feeding them, I would up the protein content in their feed in case it is feather picking, a good all flock or non medicated grower is a good choice. Yogurt and too much applesauce can give them loose dropping so I would quit that for a bit to see if that helps. I have read too many meal worms can be bad, especially if they are freeze dried.

The blood could have come from a comb injury or a toenail, both can bleed quite a bit before stopping.