Psittacosis


Published with the kind permission of Neil Forbes, BVetMed, DipECAMS, CBiol, MIBiol, FVMA, FRCVS.



Psittacosis (Chlamydiosis, Ornithosis) is a very common disease, which may affect all members of the Psittacine family as well as waterfowl, pigeons, raptors and most other bird groups. It is caused by a bacterium called Chlamydia psittaci which lives within the body's cells. The severity of disease will vary between different species of bird, and strains of the infectious organism.

Psittacosis is also a 'ZOONOSIS' i.e. it can infect and cause serious disease in humans. There are a number of important facts, of which the keepers of all Psittacine birds and Pigeon fanciers must be aware (and especially if their bird has been tested 'positive' or 'suspect' for Psiticosis).

  • Psiticosis is a disease with which birds may be infected for many years (up to 15 has been recorded) before any signs ever become apparent. Following periods of stress, or changes in the bird's lifestyle, the disease may suddenly become active.

  • Clincial signs of disease range from mild respiratory signs, sneezing and coughing, to eye discharges, diarrhoea or soft dropppings, loss of appetite, feather plucking, sudden death or simply being 'fluffed-up' and 'off-colour', ( i.e. just a sick bird). In many cases only on eof these presenting signs will be present.

  • Young birds are more prone to serious disease.


Psittacosis in Birds
  • The bird may remain healthy in all respects and yet have commenced shedding the infective agent (Chlamydia psittaci).*

  • Psittacosis cannot always be diagnosed in a bird that is a carrier. It can be confirmed in a bird that is shedding the infective agent at the time of a droppings test, or on a blood sample the bird's serologicl titre against the disease may be tested. if the titre is high it donates current or recent infection. A low titre does not, however, guarantee the bird does not carry the infection.*

  • Once a bird has been diagnosed as being 'Chlamydia positive' the bird can be given treatment which is clinically effective, BUT theres is no way of proving that the bird is not still a carrier, and it may start to shed Chlamydia again at some time in the future.

  • Treatment of birds involves continual medication for 21-45 days (depending on the drug used). One major problem with therapy is the limitation of route of drug administration in many birds. Therapy is simplest in birds that will eat soft food, to which mediation may be added. In-water therapy is rarely effective. Alternatively birds may be injected every seven days for 45 days.*

  • Stress (noise, disturbance etc) in the bird room should be minimised during therapy.

  • Infection is spread in feather dust so all birds in the same air space as one tht has been diagnosed positive will have been exposed; they too are assumed to be infected. The species most commonly affected are Cockateils. Some estimates suggest that over 30% of all Budgerigar breeding colonies are infected.

  • Mineral suppliements should be removed during therapy, as calcium in particular interferes with most of the common medications used in treating Chlamydiosis.

  • During treatment the owner shoudl disinfect the premises with an effective disinfectant. Ventilation should be improvved: feather and faecal dust should be minimised. People over 45 years of age, those on cancer chemotherapy or steroids, pregnant women and people testing HIV positive should not enter infected premises.

  • Once treated we advise regular screening (initially monthly, then 2-3 times yearly) of pooled samples of droppings collected over a three day period, or better stil a blood sample to check the birds immune status against the disease. Once treated the serological titre should gradually drop over a period of 6 months and then remain low.*

  • PreventionPsittacine birds should have an annual health check with a veterinary surgeon experienced in bird medicine, and as a minimum this should ideally include a Psittacosis test.* Only buy birds from reputable sources-ideally never from pet-shops or bird shows, always quarantine new birds (i.e. keep in isolation until tested).

  • Human DiseaseAlthough psittacosis can cause severe, even fatal disease in humans, the disease is not difficult to treat effectively, so long as your Doctor knows that you are at risk. Pregnant women, those on Immuno-suppressive treatment (steroids, chemotherapy), Diabetics, AIDS patients and anyone over 45 years are likely to suffer more diseae if they become infected.


    • Symptoms in Humans
  • Headaches

  • Flu like symptoms

  • Dizziness

  • Non-productive cough

  • Swollen glands

  • Liver problems

  • Pneumonia

    • If you have had a bird diagnosed positive, please inform your doctor. If you are suffering from any of the above symptoms and keep or come into contact with birds, pleae consult your doctor, and imform him that you keep birds or take this sheet with you.

    *It must be stressed that at present there is no test and no treatment that will guarantee a bird is free of Chlamydia.