Cockatoos are the poster child of Psittacine Beak and Feather Disease.
One of the most common reasons I see parrots is for feather loss or poor feather quality. While numerous cases of feather loss are due to self trauma, or feather picking behavior, many are also the result of underlying medical conditions. One important and serious disease in parrots known for causing feather loss and poor feather quality is Psittacine Beak and Feather Disease (often referred to as PBFD).
PBFD is a viral disease caused by a circovirus. It tends to target Old World parrots (parrots from Africa, Australia and other South Pacific regions), although it has been found in some South American parrots as well. Cockatoos are the poster child parrot, but other affected species include African grey parrots, lovebirds, Eclectus parrots, budgerigars, lories and lorikeets. Most affected parrots are young birds less than three years of age. Powder-down parrots (parrots with specialized feathers that produce a powdery dust such as cockatoos and African grey parrots) are typically most severely affected.
There are a few different disease presentations, largely dependent on the parrot? age when signs first appear. Newly hatched parrots, especially African greys and cockatoos, often die suddenly and may have liver failure or pneumonia. Older nestlings show general signs of illness as well as classic feather lesions including fractured and bent feathers, short or thickened feathers, bleeding feathers and feather loss. They typically die after a short period of sickness (6 months to 1 year), often from secondary infections (with bacteria, fungi or other viruses). Juvenile parrots (older than 8 months) show the same classic progressive feather lesions. While these older birds can live for a period of time with the disease, they also tend to die from other infections within a few years.
A major difference between feather-picking parrots and parrots infected with PBFD is whether or not the head feathers are affected.
Feather-picking parrots are unable to reach their head feathers to pick them, and therefore have normal head feathers with broken, frayed or absent wing, body and/or tail feathers. In parrots with PBFD, however, the virus affects all feathers including head feathers. It is important to note, though, that numerous other diseases can affected a parrot? feather quality, and therefore just because a parrot has abnormal feathers does not mean it has PBFD.
Signs Of Psittacine Beak And Feather Disease In Birds
Some disease presentations of PBFD are unique to the individual species. For example, beak changes such as overgrowth, cracks, fractures and infections are also possible, especially in cockatoos. Normal cockatoos should have a dusty-appearing beak; however cockatoos with PBDF can display a shiny beak due to lack of powder-down on their beak. African grey parrots can develop severe anemia. Lovebirds are unique in that they can carry the virus (acting as a source of infection for other birds) but often do not develop any signs of disease. Budgerigars are typically infected as fledglings and develop a classic appearance termed “French molt.?In addition to overall poor feather quality, these young budgies lose their wing and tail feathers and are typically unable to fly. As a result, they are also called runners or creepers. Their appearance can be identical to lesions from another virus, polyomavirus.
A parrot can carry the PBFD virus for a few weeks to years prior to showing signs of disease. The virus causes cells of developing feathers to die, leading to the classic appearance of abnormal feathers and feather loss. The PBFD virus also causes cell death in the thymus and bursa, which are two organs essential to a bird? immune system. As a result, infected birds are also immunocompromised, putting them at increased risk of developing additional infections.
PBFD is diagnosed either via serology (measuring antibodies, which are the body? response to infection), or PCR (polymerase chain reaction) testing which looks for viral DNA from a blood sample. Interpreting test results is not always straightforward, however. A parrot with feather abnormalities and a positive PCR test is infected, generally has a guarded to poor prognosis and will typically die from the disease within a few months to a few years. A normal parrot with a positive PCR test may be in the early stages of infection and will go on to develop the disease, or may be clearing the virus from its body and will never develop signs of disease. A parrot with classic feather abnormalities but a negative PCR may still be infected and should be retested.
While there is no treatment for PBFD, some infected birds can live for years with supportive care. Birds with feather changes only can live comfortably, although may need specialized cages and controlled temperatures. Birds with beak changes can be uncomfortable or painful, and may have difficulty eating. All infected birds will need monitoring for secondary infections, and will need additional treatment if other infections develop. In many cases, humane euthanasia is eventually elected.
How Psittacine Beak And Feather Disease Is Transmitted
The PBFD virus is primarily spread between parrots through ingestion or inhalation of infected fecal material or feather/skin dander. Vertical transmission, where the virus passes from the mother to her young via the egg, has also been documented. As there is no specific treatment for PBFD, prevention of disease spread by avoiding contact between infected birds and healthy birds is essential. To determine which birds are positive, new birds should be tested immediately, quarantined, and then re-tested after 90 days. In an aviary situation where there are multiple parrots, all new parrots should undergo this testing protocol while being quarantined; whereas for individual pet parrots, it is a good idea to test new birds of the susceptible species such as cockatoos and African grey parrots. Additionally, any parrot showing signs of disease should be tested as well. These precautions are the best way to quickly catch any infected birds, and to prevent spread of PBFD to uninfected birds, thereby doing the best we can to ensure the health of our parrot companions.
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