The disease of beak and feathers (PBFD) caused by the disease virus beak and feathers, is a chronic condition characterized by progressive malformation and necrosis of the feathers, the peak deformation and, ultimately, death (4). The virus also produces a general immunosuppressive effect on the bird, leading to viral, fungal, parasitic or secondary bacteria, which are often the cause of death, rather than the virus itself PBFD. Many birds infected with the disease of beak and feather die within the first year after the onset of clinical symptoms, while others may survive for several years as chronic carriers (1).
Clinical signs alone do not provide a reliable basis for the diagnosis of disease beak and feather, so trials are conducted specifically for the virus (2,3). Bioingentech can detect disease virus beak and feathers by the following techniques (1):

Technique	Reference
Conventional polymerase chain reaction	Ogawa et al., 2003(4), Olsen y Speer, 2009(5)
Real-time polymerase chain reaction	Katoh et al., 2008(3), Olsen y Speer, 2009(5)

de Kloet E, de Kloet SR. Analysis of the beak and feather disease viral genome indicates the existence of several genotypes which have a complex psittacine host specificity. Arch Virol. 2004 Dec;149(12):2393-412.
Hsu CM, Ko CY, Tsaia HJ. Detection and sequence analysis of avian polyomavirus and psittacine beak and feather disease virus from psittacine birds in Taiwan. Avian Dis. 2006 Sep;50(3):348-53.
Katoh H, Ohya K, Fukushi H. Development of novel real-time PCR assays for detecting DNA virus infections in psittaciform birds. J Virol Methods. 2008 Dec;154(1-2):92-8. Epub 2008 Oct 19.
Ogawa H, Yamaguchi T, Fukushi H. Duplex shuttle PCR for differential diagnosis of budgerigar fledgling disease and psittacine beak and feather disease. Microbiol Immunol. 2005;49(3):227-37.
Olsen G, Speer B. Laboratory reporting accuracy of polymerase chain reaction testing for psittacine beak and feather disease virus. J Avian Med Surg. 2009 Sep;23(3):194-8.