Broken Footfeathers
Freshly forming foot feathers still in their sheath are quite stiff and can break off, bleeding profusely.
The advice of a vet is to pull these feathers, especially as they can keep bleeding for a long time. If left as stubs they may not shed properly during the next moult and cause trouble for a long time.
They can be pulled out on the roost at night using pliers and pulling in the direction of the feather.