Psittacine Beak and Feather Disease (Paperback)

High Quality Content by WIKIPEDIA articles Psittacine beak and feather disease is a viral disease affecting all Old World and New World Parrots (Psittacini, Hookbills). The virus attacks the feather follicles and the beak and claws-growing cells of the bird, causing progressive feather malformation and necrosis. In later stages of the disease, the feathers develop constrictions in feather shafts, cease development early until eventually all feather growth stops. The beak and claws are affected in opposite direction - overgrowth, malformation and necrotic tissue development. Cracking and peeling of outer layers makes it possible for fungi and yeast infections to take place and complicate matters even more. The necrosis of inner layers of the beak may cause it to break, at which point the bird will be unable to feed. The disease also has a general immunosuppressive effect on the bird, clearing path for secondary systemic viral and bacterial infections which are usually the cause of death, not the PBFD virus itself.