That Bird Blog – Bird Care and History for Pet Birds

Also known as Psittacine Circovirus Disease, PBFD, which is incurable, has been identified in over 60 species of wild and captive parrots. It has been much in the news lately, and the questions I’ve received indicate that some of the coverage has been confusing to bird owners. Today I’d like to summarize what we know, and what remains to be done in the battle against PBFD.

PBFD Natural History

The virus that causes PBFD was first described in 1987, when it was discovered in a captive group Orange-Bellied Parrots, a highly endangered species.  Further study revealed that the virus occurred naturally in Australia, and likely was endemic there (found nowhere else). The disease is now established worldwide, apparently having been spread by the legal and illegal trade in parrots.

The PBFD virus is an extremely hardy organism, and likely survives for many years in nest hollows and roosting/feeding areas. To date, only one disinfectant, Virkon S, has proven able to kill it.  The virus has been found in feather dust, feces and the crop lining of infected birds.  Transmission seems to occur in several ways – direct contact with sick birds, inhalation of the virus from dust and feces and via food passed to chicks by parents. Read More »

August 1, 2008 – researchers working at the University of California (San Francisco) released the heartening news that they had identified the virus that causes Proventricular Dilation Disease (PDD), which has, since its emergence in the 1970’s, remained untreatable.  PDD has caused the deaths of wild and captive parrots of over 50 species, as well as birds in 5 other avian orders.  Aviculturists and conservationists consider it a major threat, especially to critically endangered species such as the Spix Macaw (of which less than 100 remain).

The virus, named Avian Bornavirus, is related to those that cause encephalitis in livestock, and attacks the nervous system.  Infected birds are unable to swallow, digest food or maintain their balance, and eventually die.

A test that enables technicians to positively identify the virus has also been developed.  Birds afflicted with PDD are often misdiagnosed, due the overlap of the symptoms with a number of other diseases.  It is believed that the test will assist in monitoring and limiting the spread of PDD, an extremely important step given that a cure still eludes us.

A veterinary journal article detailing a PDD outbreak in a parrot breeding center in Israel is posted at:
http://www.isrvma.org/article/61_1_3.pdf

Image referenced from Wikipedia Commons: http://en.wikipedia.org/wiki/Image:Spixara.jpg