Psittacosis — caused by the bacterium Chlamydia psittaci — is a serious respiratory and systemic infection in budgerigars that can also spread to humans. Signs include fluffed feathers, nasal discharge, watery green droppings, and lethargy; early diagnosis and doxycycline treatment are critical for both bird and owner safety.
Last reviewed: June 2026
What Is Psittacosis in Budgies?
Psittacosis (also called chlamydiosis or parrot fever) is caused by Chlamydia psittaci, an intracellular bacterium that infects birds worldwide. In budgerigars (Melopsittacus undulatus), the infection can produce everything from completely silent carrier states to life-threatening systemic illness affecting the respiratory tract, liver, and other organs. Budgies are a commonly identified reservoir species: many carry the organism subclinically, shedding it intermittently in droppings and nasal secretions, then experiencing clinical disease when stress — shipping, new environments, poor nutrition, or concurrent illness — disrupts their immune balance. As described in the AAV Basic Care for Companion Birds guidelines, all psittacine birds including budgies should be considered potentially exposed to Chlamydia psittaci, and any newly acquired bird showing respiratory signs should be tested before being housed with other birds.
Zoonotic importance: Chlamydia psittaci can infect people through inhalation of dried droppings, feather dust, or respiratory secretions from infected birds. Human infection causes a flu-like illness — fever, headache, cough, and muscle aches — that can progress to atypical pneumonia. Immunocompromised individuals face greater risk. Report potential exposure to a physician if a bird in your household is diagnosed.
Signs of Psittacosis in Budgerigars
Psittacosis can affect multiple organ systems, so signs vary considerably from bird to bird and with the stage of infection.
Respiratory signs:
- Nasal discharge — watery, cloudy, or crusty discharge around the nares (nostrils)
- Sneezing — frequent or productive sneezes
- Labored breathing — tail-bobbing with each breath, open-mouth breathing in advanced cases
- Voice changes — loss of chatter, hoarseness, or abnormally quiet behavior
Digestive and systemic signs:
- Watery, bright green or yellow-green droppings — liver involvement turns bile pigments bright green (biliverdinuria)
- Reduced appetite or complete refusal of food
- Weight loss — the keel (breastbone) becomes prominent and sharp-feeling
- Fluffed feathers and eyes closed or half-closed — the classic "sick bird" posture
Eye signs:
- Conjunctivitis — reddened, watery, or crusty eyes; sometimes the predominant sign in budgies
- Periorbital swelling
Any budgie with a combination of respiratory signs and bright green droppings, or with the classic fluffed, quiet presentation, warrants prompt veterinary assessment (AAV Basic Care for Companion Birds, 2019).
Diagnosis and Treatment
Diagnosis:
- Chlamydia PCR testing on combined swabs (choanal, cloacal, and conjunctival) or on fresh droppings is the most sensitive test
- Whole-blood PCR is an alternative
- Bloodwork may show elevated liver enzymes and white blood cell changes
- Radiographs may reveal hepatomegaly (enlarged liver) or respiratory changes
Treatment:
- Doxycycline is the treatment of choice — typically administered in food, water, or by injection for a minimum of 45 days, as described in the Carpenter Exotic Animal Formulary; shorter courses frequently result in relapse
- Isolation of the affected bird from other birds in the household is essential during treatment
- Supportive care — warmth, assisted feeding if the bird is not eating, and nutritional support are critical alongside antibiotic therapy
- Environmental decontamination — C. psittaci is inactivated by routine disinfectants; contaminated cages, food bowls, and surfaces should be cleaned thoroughly
- Zoonotic precautions — wear a mask and gloves when cleaning the cage of a bird diagnosed with or suspected of psittacosis
Prognosis is good for birds that receive prompt diagnosis and complete the full 45-day course of doxycycline. Birds that are severely ill at presentation carry a more guarded prognosis.
When to See a Vet
Call your vet today if:
- Your budgie has nasal discharge, frequent sneezing, or crusty nares
- Droppings have become watery and bright green or yellow-green
- Your budgie is sitting fluffed, eyes closed or partially closed, and is unusually quiet
- Your budgie has not eaten normally for more than 24 hours
- A recently purchased or acquired budgie begins showing respiratory or digestive signs within the first few weeks
Go to the ER immediately if:
- Your budgie is breathing with its mouth open, tail-bobbing with every breath, or has blue-tinged skin around the beak
- Your budgie has collapsed and cannot perch
- Multiple birds in the household are sick simultaneously
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Frequently Asked Questions
Can I catch psittacosis from my budgie? Yes. Chlamydia psittaci is a zoonotic pathogen — it can spread from infected birds to people through inhaled particles from droppings, feather dust, or respiratory secretions. Human illness typically resembles a severe flu and can progress to pneumonia. Immunocompromised individuals are at higher risk. If your budgie is diagnosed with psittacosis, inform your physician, particularly if you or anyone in your household has a respiratory illness.
How do budgies get psittacosis? Budgies most commonly acquire Chlamydia psittaci from other infected birds — at bird fairs, pet stores, or from new birds introduced into the home. The organism spreads through droppings and respiratory secretions. Many birds are exposed early in life and carry the bacterium subclinically for months or years, shedding it intermittently. Stress frequently triggers clinical disease in carriers.
How long does psittacosis treatment take in budgies? Treatment requires a minimum of 45 continuous days of doxycycline. This is longer than most antibiotic courses because Chlamydia psittaci is an intracellular organism that hides within cells, and shorter courses often result in relapse. The dose and delivery method (water, food, or injection) should be established by an avian vet and monitored throughout. Testing after treatment confirms clearance.
How much does diagnosing and treating psittacosis in a budgie cost? An avian vet consultation runs $75–180. Chlamydia PCR testing costs $50–120. Bloodwork and radiographs add $150–400. A 45-day course of doxycycline in appropriate formulation typically runs $40–100. An avian specialist workup — including all diagnostics — generally falls in the $300–700 range. These costs are in line with exotic and avian vet premiums of roughly 1.5–2× standard rates.
Can psittacosis in budgies be prevented? Quarantine all new birds for 30–45 days before introducing them to existing birds, and have an avian vet test for Chlamydia during that period. Purchase birds from reputable breeders rather than high-volume sources. Minimize stress for resident birds — stress is the most common trigger for subclinical infection becoming clinical. Keep cages clean and wash hands after handling birds or their droppings.
Still Not Sure if Your Budgie Needs a Vet?
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