Feathered pets are fascinating additions to the family, not to mention an incredible hobby. A 2022 report estimates that the total number of companion birds kept in Australia is approximately 3.9 million, with just over 1 million households (10.5%) owning at least one bird . However, despite this popularity, bird owners need to be aware that, although their pets might be highly intelligent and fun companions, they can sometimes make people sick (this is called ‘zoonotic disease’). This doesn’t mean you shouldn’t keep birds, but it does mean you need to be aware of the potential risks, how to avoid them, and what to do if your bird does make you sick.
Psittacosis is a disease of people caused by infection with Chlamydia psittaci. Human infection usually follows the inhalation of aerosols (from sneezing) or faecal material from birds infected with C. psittaci (although recent cases have shown the disease can also be contracted from horses). In birds the disease is known as chlamydiosis; in people it is called psittacosis.
While direct contact with parrots is still considered the primary route for transmission to humans, there have been two outbreaks of this disease, in 1996 (Bright, Victoria) and in 2002 (Blue Mountains, NSW) where the sources of infection were traced to the aerosolisation of wild bird droppings during lawn mowing, and the subsequent inhalation of this dust.
Chlamydiosis in birds
Birds may carry the infection without any signs of illness, but this will usually change under the stress associated with a change of environment (new home, new birds, etc.). In these cases, infected birds may have signs such as:
- ‘Sick bird look’ – fluffed up, quiet, eyes, closed, sitting on the floor of the cage, loss of appetite.
- Diarrhoea and excessive urination. The urates (white part of the dropping) and the urine is often green.
- Sneezing, discharge from the eyes and nose. The feathers around the eyes will often be matted with this discharge, and the bird may remove them by rubbing their face on the perch or side of the cage.
- In some cases, the bird may suddenly die without showing any signs of illness.
How to avoid this disease in your birds
Only buy birds from reputable sources and have them checked by an avian vet as soon as possible after purchase. Your vet will be able to test them for this disease. You should also quarantine new birds for at least weeks after obtaining them – use this time for a vet check, disease testing, and parasite treatment, and for allowing your new bird to adjust to a new environment.
What to do
If your bird shows signs of illness, chlamydiosis should be suspected and your bird taken to an avian vet. Diagnosis is made following a series of diagnostic tests. Infected birds respond to treatment in many instances but need to be isolated and placed on long course of antibiotic treatment, and have their cages disinfected.
Psittacosis in people
Psittacosis in Australia is considered to be a rare disease. Between 2001 and 2014 there were 1687 notifications of psittacosis reported in Australia. However, this rarity may have more to do with infections in people having been misdiagnosed, rather than not been present. Older men are reported to be the group most at risk.
What to do
Infected people may show signs of illness 5-21 days after been exposed to the source of infection. They may be asymptomatic, but most show signs of mild flu-like illness. For infected people, this can progress on to severe illness with an abrupt onset of headache, fever, chills, malaise, and muscle pain. Pneumonia can also develop, with a non-productive cough accompanied by breathing difficulty and chest tightness. In rare cases, death can occur. If people develop these symptoms within a few weeks of obtaining a new bird, they should seek the advice of a doctor.
Diagnostic tests may include a chest x-ray and taking some blood or respiratory samples to test for the bacteria. It is treated with antibiotics for a period of up to two weeks. Immunity following infection is incomplete and transitory, so reinfection can easily occur.
How to avoid
Maintain good hygiene in your birds’ enclosure to prevent the build-up of this bacterium in the environment. Always wear a face mask when cleaning an enclosure, especially if there is a new bird housed within.
Also known as hypersensitivity pneumonitis (or bird fancier’s lung, bird breeder’s lung, pigeon breeder’s lung, and poultry worker’s lung), this is a respiratory problem caused by an allergic response to inhaled dusts and chemicals . One source of this dust is birds – dried faecal material, feather dust, and even bacteria from birds. People with this condition are commonly exposed to this dust through their occupations (e.g., veterinarians), hobbies (e.g., bird keeping), the environment (e.g., a dirty cage or aviary), and the birds themselves.
What to do
Most people with this disease usually have a chronic cough, difficulty in breathing that gets progressively worse, fatigue, and weight loss. A few people will develop acute illness similar to the signs of psittacosis.
If you develop these symptoms at any time, see your doctor and let them know you have birds.
The diagnosis in people is usually made through a combination of a history of exposure to dust and the exclusion of other diseases.
How to avoid
The best treatment is to avoid the cause, as chronic exposure can cause permanent lung damage. This may mean having to give up your birds or wearing a face mask while with your birds or cleaning their cage. Air filters and improved ventilation may also help.
 Animal Medicines Australia (2022) Pets in Australia: A national survey of pets and people.
 Polkinghorne A, Weston K, Branley J (2020) Recent history of psittacosis in Australia: expanding our understanding of the epidemiology of this important globally distributed zoonotic disease. Intern Med J 50:246–249
 Chan AL, Juarez MM, Leslie KO, Ismail HA, Albertson TE (2012) Bird fancier’s lung: A state-of-the-art review. Clin Rev Allergy Immunol 43:69–83