Psittacosis or Avian Chlamydiosis - Symptoms and Treatment

By Mariana Castanheira, Licensed vet. June 13, 2022
Psittacosis or Avian Chlamydiosis - Symptoms and Treatment

Chlamydia or psittacosis is one of the most common diseases in birds. Psittacosis is an infectious disease usually transmitted to humans from infected birds of the parrot family. Birds in the parrot or psittacine family include parrots, macaws, budgies, and cockatiels (budgies). There have been cases where domestic turkeys and pigeons have also infected people. Therefore, if you live with birds or are considering adopting a bird, it is important that you recognize the symptoms and take action in case of infection.

The following AnimalWised article explains everything you need to know about chlamydiosis in birds, its symptoms, treatment, and prevention.

You may also be interested in: Psittacosis in Parrots

What is avian psittacosis or chlamydiosis?

Avian chlamydiosis, also known as psittacosis, is a disease of birds caused by the bacterium Chlamydia psittaci. This disease commonly occurs in wild birds, caged birds and aviary birds. All birds can become infected with avian chlamydiosis, but pet birds, especially parrots such as budgies, lorikeets, and cockatiels, are more likely to become infected than other birds.

Is avian chlamydiosis contagious to humans?

Yes, psittacosis or avian chlamydiosis is a zoonotic disease, meaning birds carrying this bacterium can transmit it to humans. Transmission between birds and to humans occurs primarily through inhalation of dust containing dried saliva, feathers, mucus, and feces from infected birds. Direct contact with feathers, bird droppings and litter, saliva and mucus, and contaminated food or water can also cause the disease.

The symptoms of chlamydiosis in humans are:

  • Severe headache
  • General malaise
  • Shivering chills
  • Muscle aches and pains

In any case, the incidence of avian chlamydiosis in humans is very low, although there are thousands of birds that carry the disease. Most people are resistant to the bacteria unless their immune system is weakened.

Nevertheless, transmission can occur. In humans, the infection causes psittacosis, a mild flu-like illness that can sometimes lead to severe pneumonia.

For more information on diseases that birds can transmit to humans, read this AnimalWised article where we explain how we can get infected, and what symptoms bird diseases cause in humans.

Avian psittacosis or chlamydiosis symptoms in birds

Birds infected with this bacterium may be asymptomatic, that is, they show no symptoms even though they are carriers, and therefore may infect other birds and humans. Cockatoos, for example, can live for many years as carriers without showing any symptoms.

Problems arise when the bird's immune system is weakened. Symptoms of chlamydia in birds may include:

  • Diarrhea or watery stools
  • Conjunctivitis and eye discharge
  • Sneezing and runny nose
  • Apathy
  • Anorexia
  • Weight loss
  • Sleepiness
  • Difficulty moving or flying
  • Death

The symptoms of psittacosis or avian chlamydiosis are not very specific and, in addition, different organs can be affected, such as the liver, spleen, respiratory tract and gastrointestinal tract. Therefore, if you live with one of these birds and notice a change in its behavior, be sure to visit your trusted veterinarian.

Diagnosis of Avian psittacosis or chlamydiosis

Because the clinical signs of chlamydiosis in birds are nonspecific, diagnosis is complicated. Therefore, laboratory tests are needed to confirm that it is the disease. Your veterinarian can perform the following tests to make a definitive diagnosis of chlamydiosis in birds:

  • Bone scan
  • Ultrasound
  • Liver enzyme analysis
  • White blood cell count

Even though these methods require an outside laboratory and are more costly, there is a laboratory method to isolate C. Psittaci. One of the most reliable diagnostic methods is direct detection of Chlamydophila DNA by PCR technique.

Infected birds must be isolated and have their cages disinfected. Treatment is not always 100% effective in eliminating infection, so infection may reoccur after treatment is completed, and the same bird may be re-infected with a different strain of C. Psittaci.

If you want to know more about pet birds and their different species, be sure to read this article about types of pet birds.

Treatment for Avian psittacosis or chlamydiosis

There are several treatment protocols for psittacosis or avian chlamydiosis, and the veterinarian will select the one that is most appropriate for each case.

The most common treatment is antibiotic therapy, which can be oral, water-soluble or injection. If only one bird is infected, injection therapy is probably the best option because of its effectiveness. However, if more than one bird is infected, the water-soluble option may be more practical, although it is difficult to control the amount of water each bird drinks.

On the other hand, as we explained in the symptoms section, the eye area is often affected by chlamydia, resulting in eye discharge. If this is the case with your bird, the veterinarian can prescribe the antibiotic in the form of drops applied directly to the eyes.

In addition to antibiotic treatment to kill the bacteria, other treatments may be needed to relieve symptoms.

The duration of treatment and prognosis vary greatly and depend mainly on how early the chlamydia is detected in the birds. If several birds are living together, it is advisable to separate birds that show clinical signs from those that appear healthy at the end of treatment. In general, birds should be re-examined after 45 days of treatment.

Prevention of avian psittacosis or chlamydiosis

As we mentioned earlier, birds can transmit these bacteria to other birds through nasal, oral, or fecal secretions. For this reason, it is important to keep the birds' environment clean at all times. Clean all cages, food bowls and water dishes daily. It is also recommended to moisten bedding before cleaning to reduce the risk of disease and to use bedding that does not create dust, such as a newspaper.

The risk of psittacosis is much higher in places where there are many birds, so increased caution is advised. A high population density increases the risk of chlamydia and makes it harder to disinfect everything.

If you decide to adopt or foster a new bird, quarantine it before introducing it to other birds. This way, you can catch any clinical signs before you risk spreading the disease to other healthy birds. This is especially important for clubs or rescue centers that take in birds in poor condition.

It is also critical that you protect yourself. Therefore, wash your hands with soap and running water for 10 seconds before and after handling birds, and wear gloves when handling birds that may be infected.

Finally, regular visits to a veterinarian are a highly recommended preventative measure for exotic animals. In addition, regular visits allow early detection of changes or problems in birds, improving prognosis.

If you want to learn more about different bird diseases and how we can recognize the symptoms, read the article how to tell if my parrot is sick.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Psittacosis or Avian Chlamydiosis - Symptoms and Treatment, we recommend you visit our Bacterial diseases category.

  1. Moschioni, C. Faria, H. Reis, MS Silva. E. (2001) Chlamydia psittaci severe pneumonia . Pulmonology Journal.
  • Grespan, A. (2009). Chlamydiosis in cockatoos (Nymphicus hollandicus): owner profile and therapeutic trial . Master's Thesis. Faculty of veterinary medicine and zootechnics. University of São Paulo.
  • Silva, S. (2013). Clinical and laboratory evaluation and detection of Chlamydophila psittaci in cockatoos (Nymphicus hollandicus) from the Federal District, Brazil . Master's Thesis in Animal Health. Faculty of Agronomy and Veterinary Medicine of the University of Brasilia.

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Psittacosis or Avian Chlamydiosis - Symptoms and Treatment
Psittacosis or Avian Chlamydiosis - Symptoms and Treatment

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