Hi, my Drake has a problem with the feathers around his back end. They are absorbing wet & dirt and have no repelancy all of a sudden. Any ideas?

Does he have access to swim or bath? Often that will help the situation, it is sometims a reluctance to groom because of the dirt that causes a catch 22 problem, he wont groom /oil the area because it's too muddy or dirty.

Yif he cant bath or swim then you will have to do it for him, either something like a washing up bowl of water and plonk him in so he can bath or gently wash with no soap and ease the muck away then see if he needs drying. Or if it is really bad carefully trim the bad feather off. Look for mites too as they can nest round the anus and cause poop and mud to attach to them and build up, they are like white crusty patches on the base of the feathers.