Avian Chlamydiosis

Key Points

  • Avian chlamydiosis is caused by Chlamydophila psittaci, an obligate intracellular bacterium.
  • Chlamydophila psittaci may be excreted in feces or oculonasal discharge.
  • Clinical signs may include lethargy, anorexia, ruffled feathers, oculonasal discharge, diarrhea, yellow-green urates or biliverdinuria, anorexia, emaciation, dehydration, and death.
  • Latent infections may occur in which birds may shed the organism intermittently for months to years.
  • Definitive diagnosis relies on culture, identification of antigen by immunofluorescence, a ≥ 4-fold rise in titer, or identification of the organism using stained smears.
  • More commonly, clinicians identify probable cases of psittacosis, which are defined as compatible clinical signs and a single high serologic titer or detection of Chlamydiaceae antigen using ELISA, PCR, or immunofluorescence.
  • Isolate and treat all birds with confirmed or probable psittacosis for 45 days. The drug of choice for avian chlamydiosis is doxycycline.
  • Most human cases of psittacosis result from exposure to infected psittacines, and all new bird owners should be advised on the risks of Chlamydophila infection.

Psittacosis or ornithosis is caused by Chlamydophila psittaci, an obligate intracellular bacterial infection of birds. Chlamydophila psittaci may be excreted in feces and oculonasal discharge. Chlamydophila is environmentally labile but remains infectious for months in organic debris. Latently infected birds appear healthy but shed the organism intermittently for months to years. Stressors such as breeding, shipping, crowding, or climatic extremes may activate shedding . . .

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To cite this page:

Forbes N. Avian chlamydiosis. January 29, 2008. LafeberVet Web site. Available at https://lafeber.com/vet/avian-chlamydiosis/