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Biting lice belong to the group of ecto-parasites, which are parasites that live outside
the bird. These flightless insects affect the feathered areas of their host and feed
on the feathers. There are several different varieties of biting lice that all have their
own preference in bird species. All bird lice have nearly the same lifestyle, which is
the reason for them being summarized in this chapter.
in a new version
Due to their size, which is up to three millimetres, bird lice can be seen with the
naked eye. They are often dark-coloured, have six legs and an oblong, slim trunk. They
are light-shy and crawl into the plumage when facing direct light, for example by
gently moving the primary wing feathers apart. The picture on the right side shows
how a bird louse looks like when enlarged four times.
Since lice live permanently in the plumage of birds, they reproduce there as well.
They stick their eggs in columns onto the barbs. Within one to two weeks, the eggs hatch
to produce larvae, which turn into adult lice within five weeks.
How to discover a lice infestation
A strong lice infestation manifestation results in bedraggled and thin plumage since
many lice have fed on the feathers. Affected birds suffer from itching and lack of
sleep as a result. Due to their light-shyness, adult lice are hard to detect for they
quickly hide underneath the feathers if these are blown or spread apart.
The eggs and the larvae are discovered more easily. On the underside of the flight
feathers (especially on the wings), a brown discoloration can be seen. The tips of
individual feathers are corroded and many have holes in the middle.
If an infestation of lice is suspected, an avian vet should be contacted in order to
discuss the treatment. Bird lice are generally treated with contact insecticides
(poison). A powder containing pyrethrum is often used. It is, however, not without
danger for the bird concerned. The bird will get powdered on the underside of the
feathers on the wings since the lice tend to predominately live in that area. Spraying
the plumage with Exner Petguard, which is only available in Europe, has proven to be a
lot more harmless. This treatment contains lactic acid instead of toxins. It sticks
together the respiratory openings of the lice, thus causing their death without harming
the bird. In other parts of the world similar treatments might be available in pet shops.
It has to be ensured that none of the available anti-parasite treatments - including
Exner Petguard - comes into contact with the eyes or the mucosa of the bird!
Which bird species are predominately affected?
Bird lice rarely affect budgies and most other psittacine bird species.
affect pigeons and other wild birds but can also affect pet birds that are kept in
aviaries outside and thus come into contact with wild birds. Since a transfer occurs
via body contact that enables the lice to move from one host onto another, infection
normally occurs only via this route.
German version of this text: Gaby Schulemann-Maier,
translation of this chapter: Melanie Ebenhoch.