This is one of the most serious viral diseases. It was first registered among cockatoos but has since spread to several other species. Viruses are found in excrement, feather dust and in the crop which results in the parent bird infecting the children when feeding them.
The cause of the disease is not yet known, but certain theories are in the direction of a DNA virus. In most cases, PBFD ultimately leads to a very painful death – either due to a reduced immune system, which provides good breeding ground for other infections or due to internal organs failure – so it is best to put down the bird as soon as possible.
If a bird is infected with the PBDF virus it may take up to 4 weeks before a blood test can detect the virus. If you suspect infection it may be necessary to test several times over a 3 month period to be absolutely sure. Make sure to keep possible infected birds in quarantine to avoid transmitting the virus to other birds. Also note that apparently healthy birds can carry the infection – it may then break out later, typically in connection with stress or other illness.
It is important that the test be performed by a qualified laboratory such as Avaian Biotech International in England.
The photos on this page show examples of feathers from a Gray Parrot and Lovebird with PBFD.