Bird - Chlamydophilosis

General information

Chlamydophilosis, also called 'psittacosis' or 'parrot fever', is a common disease of birds. The disease can cause chronic infections, asymptomatic (no symptoms) infections, or sudden death. The disease can also be transmitted to people. However, in spite of the many scares to the contrary it is not as common in people as previously believed. Nonetheless it is a risk especially to immunosuppressed owners.

What causes chlamydophilosis?

Chlamydophilosis is caused by an organism called Chlamydophilapsittaici. This organism is similar to a virus or bacteria but is different enough to be classified within its own special group. Like a virus, but unlike many bacteria, it lives right inside the cells of the bird, which makes it difficult to kill with treatment.

What are some common signs of chlamydophilosis in birds?

Chlamydophilosis can cause many different signs, and therefore should be suspected in any sick bird. Commonly, chlamydophilosis causes chronic respiratory (sneezing, runny eyes or nose) or gastrointestinal (change in droppings) signs. Classically, chlamydophilosis causes lime green or yellow faeces and urates (the normally solid white part of the droppings) due to chlamydophilal infection of the liver. However, this is not seen all the time and other diseases can also cause these discoloured droppings. Chlamydophilosis can also be carried asymptomatically by birds, which means they carry the infection, spread it to other birds (and people) but are not sick themselves. This is particularly the case with budgerigars and cockatiels.

How is chlamydophilosis diagnosed?

Several tests are available for diagnosing chlamydophilosis. Blood tests can usually tell if your bird has antibodies against this organism even if it is not sick. However, this simply indicates exposure. It does not prove the bird is a carrier or even if it is the cause of disease (even if correct signs are seen). Nonetheless a high antibody count raises the 'index of suspicion' and if a second test is done showing a changing level of antibody then it can be deduced that infection is active in that bird. Sick birds can have their faeces checked for the organism as well (very sensitive PCR tests are available for this); however, this test will be negative if the bird is infected but not shedding the organism. Finally, special tests can be performed on the liver, spleen, heart, and air sacs of birds that have died to check for a chlamydial infection.

In these cases, however, it is impossible to state that a bird is clear of chlamydophilosis-no test is totally definitive, if you require health screening of your bird for this disease (eg if introducing a bird to flock, or for export purposes) then this should be discussed with a specialised experineced avian vet as the testing regimes need to be performed correctly to achieve as meaningful a result as possible.

When introducing a new bird to existing pets or flock bird. It is important to remember that the disease can re-emerge when a bird is stressed. This means that any new bird should be quarantined from existing birds for a period of 2-12 weeks depending on source and results of chlamydophia testing.

In people the infection will cause a respiratory 'flu-like' disease. It can be contracted from infected droppings or respiratory discharges via the nose, mouth or eyes. It can be very severe and can cause death. Waterfowl and pigeons are a more common source of human infection than parrots.

However, owners of infected birds should be warned that no treatment regime (most last 40-50 days) has been shown to clear a bird of infection – i.e. they will always be carriers. Therefore there will always be some risk of infection to other birds and owners as well as risk of re-occurance in the patient.

Owners should be advised on clinical signs and to consult their doctor if suffering from heavy ‘flu. They should be advised to wear gloves, mask and goggles when cleaning out potentially infected birds and always to wash hands after handling their bird.

Where birds belong to immunosuppressed owners – e.g. those with HIV infection or are on immunosuppressive drugs, it may not be appropriate for them to keep the bird.