Plumage defects due to French Moult

Reasons for the disease and its transmissibility
It's the so-called Polyoma virus that causes BFD. Until today the way of infection with these viruses it is not known in all its details. Some guess that the infection happens in the egg already. But this allows only one conclusion: Old birds that are infected chronically with the Polyoma virus transmit the pathogenic germ to their offspring in the nest. Thus, it is wantonly negligent to breed budgies suffering from the French Moult! The pubescent infected birds would transmit the disease to their offspring and raise with an utmost probability a new generation of ill birds.

Birds who suffer from BFD are disabled, they are restricted in their everyday life. Even flightless birds can enjoy a beautiful life as their flying fellows. But it is ethically questionable how to rank the conscious breeding of birds that will be disabled with an utmost probability. Opinions differ a lot, so everybody should decide himself whether to consider this as correct or not.

As the chronical infection with Polyoma viruses does not result in the BFD for all budgies, the French Moult often appears without any warning. A budgie just carrying the virus does not look ill or infected, some birds have an intact plumage and show no symptoms of the disease.

Can older birds infect each other?
The danger to be infected as an adult bird still is discussed in research. Some scientists believe infected birds can transmit healthy but old fellows. These older birds do not loose their plumage but they are mediums of the viruses from this moment on. As soon as they are breeding, the circle closes and their offspring will most probably suffer from the BFD - at least in theory.

The second part of avian vets refuses this hypothesis and thinks to be able to prove it. On their opinion transmission between elder birds is not possible. Only young birds can be infected by their parents who have been infected by their parents and so on.

Unfortunately there are no final evidences for both theories. As a bird keeper you have to consider properly whether to get an infected bird into your flock or not. If the fraction of the first theory was right, the complete flock can be infected and unusable for further breeding, if you are against breeding budgies with a disablement.

I can't and don't want to give a recommendation for keeping infected birds in a "normal" flock at this place. Every bird keeper has to decide for himself how important ethical aspects are and if there even should be plumed offspring.

Can the French Moult be healed?
Until today, no therapy that could heal the French Moult is known. Affected birds who wear extremely breaking feathers can be supported by special food supplements and by an increased donation of silicic acid. New feathers are supplied optimally with nutriments and usually regrow stronger then.

The manifestations of the French Moult
The French Moult can show different occurrences. Comparatively harmless was the course of disease in Tethys' case, she was one of my birds. The photo on the right shows that she only lacked the primary and tail feathers, thus she was nearly completely unable to fly. She could not get higher when she was flapping with her wings. But if I set her to a higher place in the bird room and later she wanted to go back to her favourite branch which laid on the floor she spread her wings and fluttered slowly down losing height. She didn't fell down like a stone because with her few secondary feathers she was able to decrease speed and land softly.

In 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 suffers from an extreme French Moult. Her entire body shows naked skin and she is not able to fly. In winter she loves to perch on her favourite branch which is placed on the floor of my bird room right in front of the heater. People who care for such naked birds must provide a room temperature of at least 20 degrees Celsius. Else the birds would feel cold because of the lack of feathers and they can become 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 ("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 budgie lady Flöhchen. Their keeper made the cage safe because birds without feathers can hurt their skin when they fall off their perch.

German version of this text: Gaby Schulemann-Maier, English translation of this chapter: Isolde Aufschläger .

Link tip: Do you want to discuss with experts and other bird owners about your bird's health? Then please feel free to visit the English forum of . Of course you will meet me there, too. My nickname is "Feenseeschwalbe".

This chapter in Turkish on muhabbetkusu.org