Psittacine Diseases Part Two — Psittacosis

Last time we examined beak and feather disease in parrots and related species. Our focus on parrot diseases continues with a look at psittacosis, or parrot fever, a bacterial infection that affects parrots, other birds, livestock and humans. The cause is the small bacterium Chlamydophila psittaci and is transmitted by inhalation or contact. Parrot fever can be transmitted to humans from their pet birds, but the infection is treatable.
Polly Wants a Doctor
A parrot infected by C. psittaci can suffer from a variety of symptoms, including:
• Discharge from eyes and nose, accompanied by sneezing, wheezing or coughing
• Fluffed-up, weak appearance
• No interest in food
• Discoloration of droppings
• Diarrhea

Some victims show symptoms only sporadically, and some don’t show any symptoms at all. The latter may be due to a good immune system or an early stage of infection, and may create a “Typhoid Polly” — infectious without symptoms.



Avian Vet
Involving Your Avian Veterinarian Early Is The Smartest Move


Diagnosing psittacosis presents a challenge to your veterinarian, because its symptoms are shared by many other diseases, both infectious and non-infectious. Normally, preliminary testing includes a plasma biochemistry panel, blood count and X-rays. These help your vet eliminate many other diseases. Once your veterinarian suspects psittacosis, one or two tests can pinpoint the diagnosis. The first test looks for the DNA of the C. psittaci bacterium from a blood sample and/or a sample swabbed from the bird’s mouth and cloaca. The second test sensitively measures the bird’s immune response to C. psittaci, using a blood sample.


The standard treatment for psittacosis is a series of antibiotic injections or drops, such as doxycycline or tetracycline. Your vet may use a series of four weekly shots of a long-acting antibiotic. Injections are more reliable than oral doses, because the veterinarian is sure that all the dosage is administered. One month of treatment is the minimum, because C. psittaci lives in the bird’s cells and are vulnerable only when it moves from one cell to another. At this time, there is no vaccine available to inoculate against parrot fever.


Prevention begins with parrot breeders, by quarantining and testing new flock members. Unfortunately, some breeders run parrot mills in which no care is expended for the health of the parrots. These merchants may sell you an infected bird and may even lie about the bird’s health. It’s best to use a bird source recommended by your veterinarian. Pet shops and distributors that do not practice quarantine procedures can unwittingly spread diseases among new birds.
Your safest course of action is to bring any new pet, including parrots and other birds, to your veterinarian for a checkup and perhaps some diagnostic testing for psittacosis and other common diseases. If you own other birds, you should quarantine a new one for a month or two to protect the flock.

Infecting Humans

As we mentioned, the C. psittaci bacterium is very happy to use a bird as a vector to get to you. After incubating for a period of 5 to 19 days, the symptoms may range from unnoticeable to ones that resemble severe pneumonia. It can also mimic typhoid fever, and produce joint pain, fever, nosebleed, severe headache, diarrhea, conjunctivitis and a low white blood cell count. Horder’s spots may appear on the skin and you may develop an enlarged spleen. In the most severe cases, coma may follow and, rarely, death. If not treated, complications can occur, such as inflammation of internal organs and the brain. Tetracycline and chloramphenicol are effective, orally administered treatments for psittacosis in humans.
As you can see, it always pays to have your vet examine new pets and to set up a recurring schedule of checkups.