Ornithosis is an infectious disease that affects many bird species worldwide. It
can also be transmitted to humans and other mammals. In Germany, ornithosis is a
notifiable disease in pigeons.
Pathogen:Chlamydia psittaci. Chlamydia are small, non-motile micro-organisms that invade
cells parasitically. Infection occurs via inhalation of stirred-up dust containing the
pathogen, uptake of faecally contaminated feed or water, or else billing or feeding
of squabs.
Symptoms of the disease:Ornithosis occurs in 2 forms:
The acute form can be recognised in young pigeons from: wheezing noises, uni- or
bilateral conjunctivitis and muco-aqueous enteritis with diarrhoea .
The chronic form is more often found in adult birds, which, however, show few or
no signs of the disease. Pigeons that have recovered are a dangerous source of
infection for young pigeons and for humans due to their latent shedding of the
pathogen.
Recognition of the disease:The disease can be demonstrated in dead pigeons by microscopic examination of a
smear or impression ("klatsch") preparation of spleen, liver, conjunctiva or air sac
that has first been stained using the method according to Stamp. In live birds,
the pathogen is demonstrated in faeces, via a sink dab from the cloaca, or
alternatively by serological identification of specific antibodies.