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The French moult is a disease that
occurs in budgies and some other pet bird species. First symptoms can
typically be observed when the birds are still very young.
At first, the chicks seem to develop in a normal way. But then the
fledglings (young birds) whose plumage is nearly full-grown
suddenly lose all their secondary and tail feathers - these are the
longest feathers. In most cases this happens when the birds are about
six to eight weeks old. Some birds lose all these
large feathers, others are lucky and only lose a a few large feathers. Usually,
the small feathers that are covering a bird's of the body, e.g. the belly,
are not affected
by the disease. In some cases, however, abnormalities of the body plumage is known. Nearly
all birds suffering from the French moult are not able to fly for the rest of their lives
because their wing feathers which provide the ability to fly either never grow
- if they do - grow with abnormalities. Most affected birds are able to run very fast, others
just hop around.
What causes the disease and how is it transmitted?
Until today the way of infection with these viruses it is not known in all its details. Some experts claim that transmission takes place in the nest; the virus is transmitted from the parents to the eggs. Thus, it would be no good idea to knowingly let budgies who suffer from the French moult have chicks! The risk of a new generation of infected birds is too high.
Another big problem is that in some cases adult birds carry the virus without showing symptoms of the disease. They can transmit the pathogenic germ to their chicks and the disease seems to occur out of nowhere. Therefore bird owners who would like to breed should keep this potential danger in mind and let their birds undergo a test that can tell whether they are infected or not.
Can older birds transmit the disease to other adult birds?
Unfortunately there are no final evidences for both theories. As a bird owner you have to consider properly whether to adopt an infected bird and let it become a member your flock or not. If the first hypothesis would be correct, the complete flock could be infected and therefore would be unsuitable for further breeding.
I'm not able and willing to give a recommendation for keeping infected birds in a "normal" flock at this place. Every bird owner has to decide for herself (or himself) how important ethical aspects are and if she (or he) has any breeding attempts.
Is there any cure?
Typical symptoms of the French moult in budgies
The typical symptoms of this disease in an adult budgie who became infected as a chick is shown in the photo on the right. All large feathers on the wings (the primaries) and the tail feathers are missing. The remaining feathers are often broken due to mechanical stress. The reason for this is that the birds often try to fly and then stumble to the ground. You have to make sure that affected birds can't climb up too high because if they would fall, severe injuries like broken bones could occur.
In the rare case of an extreme French moult, birds not only lack the large feathers. They also lose their small feathers and some birds become more or less naked. Medea who lives in my bird flock is shown in the photo on the right. She suffered from an extreme course of the French moult. Her entire body showed patches of bare skin and she of course wasn't able to fly. In winter she loved to perch on a branch which was placed on the floor of my bird room right in front of the heater. People who care for birds like her should provide a room temperature of at least 20 degrees Celsius. Else the birds would feel cold because of the lack of feathers and they are in danger of becoming ill due to the low temperature. They should be brought out of the room while the window is open in winter.
The photo on the right shows the male budgie Fröschlein (this is German and means "little frog") who also suffered from a very extreme form of the French moult. This handicapped bird lived in a large cage together with his beloved fellow called Flöhchen. Their keeper made the cage safe for them because birds without feathers can hurt their skin when they fall off their perches. Therefore the cage floor had been padded to avoid any injury. Please note that the severe form of the French moult is very rare and that most birds who look like Medea or Fröschlein do not suffer from this disease but from PBFD. This disease is even more grave and therefore birds who show patches of naked skin should be tested for Polyoma virus and PBFD. It is impossible to tell the symptoms of these diseases apart by just having a look at a bird.
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