Psittacine Beak and Feather Disease

What is Beak and Feather Disease in Birds?

Psittacine beak and feather disease (PBFD) is also known as psittacine circovirus (PCV) or Psittacine Circoviral Disease (PCD). This is a viral condition responsible for damage to the beak, feathers, and nails as well as the immune system of infected birds.

PBFD disease was first recognized during the 1970s in Australian cockatoos and has affected over 50 species of wild and pet parrots. The virus is found most frequently among cockatoos, African grey parrots, lovebirds, lories, lorikeets, Eclectus parrots, and budgerigars.

Types of PBFD in Birds

Peracute

The peracute form of PBFD occurs in recently hatched birds. Symptoms are caused by bacteria and bacterial toxins in the bloodstream, pneumonia, infection of the small intestine causing diarrhea, regurgitation from crop stasis causing weight loss, and death.

The diagnosis is easily missed when a postmortem microscopic examination of tissues is not performed, since birds die before feather abnormalities are recognized. The onset is sudden–only lasting a few hours with rapid progression that is quickly fatal.

Acute

The acute form of PBFD develops in infected young birds as they develop their first feathers. Symptoms are often first seen between 2 months and 3 years of age. Signs include depression for a couple of days, sudden changes in the formation and appearance of the developing feathers, and premature molting. Some of these birds may die within 1-2 weeks after symptoms appear.

Chronic

The chronic form of PBFD occurs in older birds (up to 20 years of age) as they develop abnormal feathers in a symmetrical pattern, which happens over successive molts. This occurs in the first molt after infection or up to 6 months later.

Short, clubbed feathers and deformed curled feathers are seen. These changes occur in birds that have survived the acute stage of the disease. If affected birds live long enough, they may develop baldness. Beak deformities may also develop after a long course of the disease where substantial feather changes have taken place.

Some birds will become carriers of the disease as a potential source of infection to other birds. Others will eradicate the disease and be left with a natural immunity that can be passed on to their offspring.

The affected birds may live months to years before dying of secondary viral, fungal, bacterial, or parasitic infections. Signs will include depression, elevated white blood cell counts, regurgitation, rapid weight loss, diarrhea, pneumonia, feather loss, weakness, and death. This resulting diminished immunity may cause death before the feather changes are recognized within months to years after infection.

Symptoms of Beak and Feather Disease in Birds

Symptoms of PBFD can be seen in the following:

• Feathers: short, sharp, fragile, malformed feathers which bleed and break causing significant loss of powder down, and contour feathers with loss of pigment in a symmetrical pattern

• Skin: scarring, scaly, thickened, moist skin, skin infections, loss of temperature control

• Beak: initially glossy then dull, brittle, and malformed

• Nails: brittle and malformed

• Internal organs: immune system failure including the thymus, Bursa of Fabricius, and bone marrow

Causes of Beak and Feather Disease in Birds

The virus responsible for PBFD is a circovirus named for its circular shape. It is one of the smallest viruses known to cause disease and is extremely resistant to degradation in the environment. It does not mutate often so there are not many variants.

PBFD is transmitted from direct contact of infected birds to healthy birds or through contaminated water and feeding areas. The nares, mouth, and cloaca are potential routes of entry. The disease may be passed from crop secretions to newly hatched birds being fed by their parents. The dust from feathers, dander, or feces found in the nest box can also spread the virus.

How Veterinarians Diagnose Beak and Feather Disease in Birds

PBFD is diagnosed using a DNA probe test on a blood sample. Testing may also be performed on feather or skin samples or a swab from the internal organs of a deceased bird. Incorrect results rarely occur.

Treatment of Beak and Feather Disease in Birds

PBFD is a fatal disease. There is no cure or specific treatment for it, so prevention is key. Birds infected with PBFD may live months to years after initial infection, but do eventually succumb to the disease. Pet parents can help their PBFD-infected bird live longer through a few different practices.

Cleanliness and sanitation are a must since there is no disinfectant which kills the circovirus that causes PBFD in birds. Regular cleaning with an appropriate disinfectant is necessary. Creating a stress-free environment may help to lengthen the bird’s lifespan. Infected birds should be isolated from other birds to avoid spreading the virus.

Vitamin, mineral, and probiotic supplements are recommended to support the immune system. Supportive care for secondary infections with oral antibiotics and antifungals medications may also be prescribed on a case-by-case basis.

Recovery and Management of Beak and Feather Disease in Birds

Infected birds should be kept isolated from non-infected birds to prevent transmission. Supportive care in a stress-free environment may help extend the life of infected birds. Good nutrition, supplemental heat in an incubator, beak trimming, and treatment of secondary infections will be helpful. Any birds that are featherless may benefit from a wrap or sweater to improve body warmth.

This virus causes critical suppression of the immune system in infected birds. Secondary infections are common which may cause death. PBFD is much like human immunodeficiency virus (HIV). PBFD tends to weaken the immune system and make the bird more susceptible to other diseases it would normally be able to fight off.