If the parrots of the Old World show great sensitivity to the virus, those of the New World seem much more resistant to the infection. In the latter, the clinical disease is rarely encountered. therefore are Two scenarios possible for them:
1. Transient infection (with or without feather symptoms) followed by virus removal.
2. Active disease with the same symptoms as described in cockatoos and the same prognosis.
The species most often affected by the disease are:
African Grey Parrot
|symptoms observed||results of the blood tests|
|Ulcerative dermatitis of the inseparable||Approximately 20% are positive for beak and feather disease. More than 50% are positive for polyomavirus.|
|Feather loss syndrome||65% are positive for beak and feather disease. 16% are positive for Polyomavirus.|
|Polyfolliculitis||All negative for beak and feather disease and polyomavirus.|
Disease in the Lovebird
The disease appears common in this species and is considered enzootic in several Lovebird populations. There are asymptomatic carriers. Various studies in the United States indicate that 40% to 60% of the Lovebird tested are positive for the virus. The results of another study corroborate these data.
60% of the Lovebird tested are positive for the virus. The results of another study corroborate these data.
In the inseparable, the disease most often manifests itself in young adults: poor plumage, feathers that fall easily and do not grow back, delayed molt, deformed feathers. Several birds survive several months or even years after the appearance of feather abnormalities. It even happens that some individuals manage to completely eliminate the virus from their system and heal. This is what we wish for baby Kiwi!
Disease in cockatoos
In parrots over 6 months of age, the disease tends to be chronic and progressive. In general, feather symptoms appear as early as 6 months of molting, but sometimes take up to 3 years to develop. At first, they are usually subtle:
A decrease in powder production. The feathers that produce the powder are very sensitive to the effect of the virus and are therefore the first to be attacked. Without powder, the beak and legs that are normally gray become black and glossy.
It’s a delayed molt story. Presence of some deformed feathers: constriction at the base, hemorrhages in the pulp, thickened keratin shell and retained on the feather, feathers growing sometimes short and strangled. Feathers that fall abnormally. Deformed feathers replace the beautiful ones. Over time, the bird thins out and keeps only a few down and feathers around.
Varying skin conditions. They are much less common than feather lesions.
As the disease progresses, abnormalities in the beak may occur:
Abnormal elongation of the beak due to the thickening of the keratin layer that covers it.
Transverse or longitudinal fractures
Necrosis of the palace
Ulceration of the interior of the beak
Beak fracture with bone exposure. This situation is extremely painful and causes anorexia.
Nails can also be affected by similar changes to the beak.
Secondary bacterial and/or fungal infections are not uncommon due to the weakening of the immune system by the virus. The general health condition of the bird is therefore compromised. In the event that lesions to the beak are small, the parrot may live several years with the disease. However, most die between 6 and 12 months after the onset of the first clinical signs. In the young baby parrot still in the nest, the disease is more acute and generalized. The chick often lacks energy and regurgitates. Feather lesions appear quickly and are very marked. Feathers fall and break easily. Damaged feathers are painful and the baby is very uncomfortable. Most die quickly, long before lesions to the beak and claws occur.
Disease in the parakeet
Symptoms are observed in young people when they are weaned. At this time, the young parakeets covered themselves with normal feathers but no primary and secondary flight feathers grew. The polyomavirus is also responsible for such symptoms.
Disease in the lory When feather abnormalities become visible, the lory usually dies quickly. However, some cases of spontaneous healing have been reported
Disease in the Eclectus
This species does not tend to show classic feather symptoms. It is mostly anarchic and delayed molts that are observed. Poor overall plumage quality is sometimes the only change noted.
Disease in African grey
An acute form of the disease is described in the very young parrot. It is characterized by weakness, stasis of the jabot (slow to empty) and regurgitation. Death follows quickly.
Adults are either asymptomatic carriers or have generalized dystrophic plumage, classic disease. Feather lesions are sometimes confined to tail feathers only. In some individuals, only a few red feathers grow through the gray plumage. However, these ectopic red feathers are not exclusive to the disease and malnutrition could also be responsible for this phenomenon.
Mode of transmission and incubation
It is by inhaling or ingesting viral particles that a parrot becomes infected. A large amount of virus is normally found in feathers (considered highly contagious), dandruff, feces, and crop secretions.
In baby parrots, clinical signs usually appear 2 to 4 weeks after contact with the virus. In other cases (especially in slightly older birds), incubation can last from a few months to a few years. The virus appears in the blood before external symptoms are noted.
With or without symptoms suggesting beak and feather disease, it is wise to have any new bird tested as soon as it is acquired. Two tests are available:
1. Testing for the virus (antigen) in blood, stool, crop secretions or feathers. This test is called PCR (polymerase chain reaction). It is possible to detect viruses in the blood of a bird 7 to 14 days after the beginning of the infection. The bird is then viremic. It remains so if it is unable to produce enough antibodies to neutralize them. The disease then continues.
2. Blood antibody testing (haemagglutination test). Antibodies can be detected as soon as 1-2 weeks after exposure. Theoretically, antibodies have a protective effect against disease when they are in large numbers. Some studies have shown that it is birds that produce little or no antibodies that develop the clinical signs of the disease.
Feather biopsies are almost no longer used as a diagnostic tool, the PCR and the haemagglutination test being very reliable.
Interpretation of the results
In a parrot with suggestive symptoms of the disease, a positive PCR predicts a very reserved for poor prognosis.
In a parrot without symptoms, if the PCR is positive, you have to retest in three months. Maybe the bird got rid of the infection.
In a parrot without symptoms, the presence of antibodies in the blood does not necessarily indicate that the bird is sick. The test only indicates that he was in contact with the virus. A second test is needed to determine whether the amount of antibodies increases or not. If they increase, the bird actively fights the virus. It will develop the disease or perhaps it will heal. If they decrease, the bird has managed to get rid of the virus. In a bird with symptoms of the disease, the test predicts the same prognosis as PCR.
Test any bird as soon as it is acquired and strictly respect its quarantine.
Ideally, retest the bird 1 month later to ensure it was not in the incubation phase undetectable by the test.
Adequately isolate positive birds.
If the number of parakeets or lovebirds living in an aviary does not allow them to be tested individually, take a dust sample from their environment and have the sample analyzed by the PCR test.
Since the virus is very resistant in the environment (few common disinfectants manage to deactivate it, apart from 10% bleach and 10% iodine), have the environmental dust analyzed by the PCR test following disinfection.
Beak and feather disease is devious and can strike where it is least expected. Since no vaccine is yet available, prevention through the screening of individuals and contagious sites is strongly recommended.
For a parrot with the disease, euthanasia is not necessarily the solution. It is possible to keep it, taking care never to put it in contact with other birds. Small attention can make life easier: optimal captivity conditions, treatment of secondary infections if necessary, administration of immunity stimulants, avoidance of stress.