Psittacine beak and feather disease (PBFD) is a chronic disease characterized by feather dystrophy and loss, beak deformity and ultimately, death. It is caused by a non-enveloped icosahedral DNA virus belonging to the family Circoviridae. The disease has been reported in Australia, North America, Europe and Asia. Most species of parrots, such as cockatoos, African grey parrots, eclectus parrots and lovebirds, can be infected by this virus. Recent study also shows that PBFDV can cause feathering problems in some of the ringneck parakeets and budgerigars in South Africa.

PBFD virus usually infects birds less than 3 years of age. The virus is spread from mother to egg or directly to chicks. Viral particles can be spread in feather dust carried by air currents, dried feces or even on the clothing of human handlers. Nest materials, feeding formula, feeding utensils, nets, bird carriers, food dishes and other fomites are easily contaminated with this virus. Since the virus particles can remain viable in the environment for months, long after the infected bird is gone, there is a high potential for widespread infection of an entire flock of birds.