2, non-molting hair removal is mostly parasites or affected by external forces. For example, improper methods of catching pigeons can easily lead to feathers falling off its back.
3. Pigeons have skin diseases, and their breasts will lose hair. In this case, you can find some fine sand, put pigeons on it and let them bask in the sun. Pigeons will bathe in sand and put some gravel in their food to help their digestive system. The cage space should be larger, and pigeons can fly to be healthy.