Psittacosis (also known as "parrot fever", ornithosis. or chlamydiosis)
is a widespread disease caused by an organism called Chlamydia Psittaci. The pet bird owner may be increasingly
aware of the prevalence of psittacosis, but that is believed due to improved diagnostic methods rather than an
actual increase in disease incidence.
Transmission of psittacosis is primarily through inhalation of infected dust from
droppings or feathers, and is enhanced by close contact with sick birds that are shedding the organism. For this
reason the disease is most often seen in birds that have been recently imported, housed in pet shops, or boarded
with other birds. Birds do not have to show symptoms of disease in order to transmit Chlamydia.
There are no specific signs that are! characteristic of psittacosis. Some birds
may show general "sick" symptoms - lack of appetite; weight loss; depression and listlessness; watery
green droppings; discharge from eyes or nares or even sudden death. Of course, these signs may be related to diseases
other than psittacosis. Many birds carry the Chlamydia organism, but do not show any signs of disease under stable
conditions. These birds may become sick after some stressful occurrence, or breeding birds may pass the organism
on to their offspring, which may die in the nest or at weaning. Young birds are more susceptible to debilitating
infection than are adult birds.
Positive diagnosis of chlamydiosis in the live bird is sometimes very difficult,
depending on the species, length of time since exposure, and general condition of the bird. In addition to having
the capability of producing disease on its own, Chlamydia undermines the immune system and opens the body to a
host of other pathogens: thus bacterial or viral disorders may be occurring at the same time. Because it is far
easier to diagnose a bacteria problem, the chlamydiosis may be missed. Some chlamydiosis screening tests are available
through outside laboratory services, and new tests are being developed that will help your veterinarian diagnose
psittacosis in his clinic. There is no single diagnostic test in the live bird that can absolutely show the presence
of Chlamydia in all cases. Your avian veterinarian may be able to make a presumptive diagnosis of psittacosis based
on history clinical signs, x-rays, blood work, or other diagnostic methods. If psittacosis is suspected, treatment
should begin at once, even as confirmatory tests are being run.
If psittacosis has been diagnosed in one of your birds, your veterinarian may recommend
treatment of all expose and potentially infected birds, or exposed birds may be tested first and treatment limited
to those that test positive. To reduce the spread of the disease, it is imperative that the patient be isolated
from other birds on the premises.
The success of treatment depends on the species, age, presence of concurrent infections
and immune status of the patient. Medications can be given by direct oral administration by injection, as medicated
pellets, or mixed in so foods. Water medication, such as an over-the-counter product, is not an effective treatment.
The specific medication and route of administration are left to the discretion of the veterinarian. The treatment
period will last a minimum of 45 days. Depending on the condition of the patient. other forms of supportive therapy
may be necessary. There is no immunity to the disease, and birds are susceptible to reinfection even after full
recover or previous treatment.