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Avian Chlamydiosis

Chlamydiosis, Parrot Fever, Psittacosis, Chlamydia, Ornithosis

Avian chlamydiosis (AC) is a zoonotic disease of birds and mammals, including chickens, caused by infection with the Gram-negative, intracellular bacterium, Chlamydia (Chlamydophila). The genus consists of 11 different species from the Chlamydiaceae family. Chickens are predominately affected by C. psittaci, C. gallinacea and C. suis. Clinical signs of AC are non-specific, and can include diarrhea, nasal discharge, greenish-yellow feces, ruffled feathers, loss of appetite, and Conjunctivitis.

Transmission
Birds are the primary hosts of Chlamydia spp., and a wide range of avian species are susceptible to infection. Numerous wild birds have been reported to be infected with Chlamydia spp. worldwide. Generally, these wild birds are asymptomatic (showing no evidence of illness despite being infected), however they will may intermittently shed the bacteria in nasal secretions and feces, especially when stressed. Chickens become infected with Chlamydia spp. by inhaling aerosolized respiratory or nasal secretions or contaminated dust, soil, and bedding particles, or through ingestion of contaminated feeders, waterers, or pasture forage.

Clinical Signs

Greenish-yellow diarrhea
Coughing
Open mouth breathing
Ruffled feathers
Depression
Lethargy
Conjunctivitis
Weakness
Sneezing
Nasal discharge
Weight loss

Diagnosis

  • History
  • Clinical signs
  • PCR
  • Radiographs
  • Endoscopy
  • Cytology
  • Sinus flush and culture

Treatment

NameSummary
Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
Chlortetracycline HCl2.5 g/L (drinking water), 2.5 g/kg food (in feed), or 20-60 mg/kg administered orallyK Marx
Doxycycline75-100 mg/kg administered IM every 5 to 7 days for 4 weeksK Marx
Colloidal silverA few drops administered inside the chicken's mouth or position just next to the nares, for them to inhaleG Damerow
Apple cider vinegarMay help clear mucus from the mouth and throat. Add 1 tablespoon of apple cider vinegar to each gallon of water (double dose if using hard water)G Damerow

Prevention

  • Minimize exposure to wild birds
  • Do not hang wild bird feeders, as you don't want to attract wild birds.
  • Do not expose chickens to exotic wild birds, as they are common carriers.
  • Thoroughly wash your hands and/or change clothes before handling your flock after visiting pet stores and zoos.

Scientific References

Good Overviews

Risk Factors

  • Wild birds on the premises
  • Exposure to exotic pet birds
  • Hanging wild bird feeders on your property
  • Stress