Psittacine beak and feather disease is a viral disease affecting all Old World and New World Parrots (Psittacini, Hookbills). The virus belongs to the family Circoviridae. It attacks the feather follicles and the beak and claw matrices of the bird, causing progressive feather, claw and beak malformation and necrosis. In later stages of the disease, feather shaft constriction occurs, hampering development until eventually all feather growth stops. It occurs in an acutely fatal form and a chronic form.
The beak and claws may develop overgrowth, malformations, or may become necrotic. Cracking and peeling of outer layers makes it possible for secondary infections to occur, which typically are the cause of death in fatal cases, as opposed to the PBFD virus itself. Necrosis of the inner layers of the beak may cause it to break, at which point the bird may be unable to feed.
Data from Ross Perry FACVSc (Avian health) suggests PBFD also has a general immunosuppressive effect, exaggerating secondary infections.
Read more about Psittacine Beak And Feather Disease: History, The Beak and Feather Disease Virus, Infection Paths, Signs of Disease, Threat, Treatment
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