Chlamydiosis (psittacosis) in cockatiels is a bacterial infection caused by Chlamydia psittaci that causes respiratory signs, lethargy, and abnormal droppings — and can be transmitted to humans. Cockatiels are often silent carriers for months before showing symptoms, making routine wellness exams and testing critical for bird-owning households.
Last reviewed: June 2026
What Is Chlamydiosis in Cockatiels?
Chlamydiosis — also called psittacosis, parrot fever, or ornithosis — is caused by the obligate intracellular bacterium Chlamydia psittaci. Cockatiels are among the most commonly affected companion birds, in part because of their popularity and the frequency with which they are traded through pet stores and bird fairs. The bacterium infects cells lining the respiratory tract, gastrointestinal tract, and systemic organs including the liver and spleen.
Critically, C. psittaci is a zoonosis — it can infect humans, causing flu-like illness that can progress to severe pneumonia, particularly in immunocompromised individuals, the elderly, and children. This dual bird-and-human health concern makes accurate diagnosis and appropriate treatment not just a welfare issue but a public health matter, as detailed in Carpenter's Exotic Animal Formulary.
Transmission occurs through inhalation of dried fecal particles, respiratory secretions, or feather dust from infected birds. A cockatiel can shed the organism intermittently without showing visible signs, especially during periods of stress (transport, breeding, new environment), which is when shedding increases dramatically.
Signs of Chlamydiosis in Cockatiels
The classic presentation in cockatiels includes some or all of the following:
- Lime-green or yellow-green urates in droppings — one of the most distinctive signs; urates should be white
- Respiratory signs — sneezing, nasal discharge, labored breathing, tail-bobbing with breathing
- Lethargy and fluffed feathers — the bird looks "sick" and sits low on the perch
- Reduced appetite and weight loss
- Eye discharge (conjunctivitis) — unilateral or bilateral
- Loose, discolored droppings overall
Subclinical infection is common — some cockatiels test positive with no visible signs. Birds stressed by overcrowding, poor nutrition, or recent purchase are at highest shedding risk. A bird that appears healthy can still transmit the disease to other birds and to people in the household (AAV Basic Care for Companion Birds, 2019).
Diagnosis and Treatment
Diagnosis is made by a combination of methods because no single test is 100% sensitive:
- PCR testing of choanal swab and/or feces — most sensitive for active infection
- Serology (ELISA) — tests for antibodies; useful for confirming prior exposure
- Complete blood count and chemistry — often shows leukocytosis and elevated liver enzymes (hepatomegaly is common)
Treatment is with doxycycline for a minimum of 45 days, either orally or by injection. The 45-day protocol is essential because shorter courses do not reliably eliminate the organism. During treatment, all in-contact birds should be tested; the household should be cleaned with disinfectants effective against chlamydiae; and owners should discuss exposure risk with their physician.
When to See a Vet
Call your vet today if:
- Your cockatiel has lime-green or yellow-green discoloration in its droppings
- You notice sneezing, nasal discharge, or labored breathing
- The bird is fluffed, lethargic, or sitting low on the perch
- A bird recently joined your household from a store, fair, or breeder
- Anyone in your household has developed flu-like symptoms after contact with your bird
Go to the ER immediately if:
- Your cockatiel is breathing with an open beak, tail-bobbing severely, or struggling to breathe
- The bird is unresponsive or collapsed
- Weight loss has been rapid and the bird feels noticeably light when held
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Frequently Asked Questions
Can I catch psittacosis from my cockatiel? Yes. Chlamydia psittaci is a zoonotic pathogen that can infect humans, causing flu-like symptoms and in some cases severe pneumonia requiring hospitalization. Transmission is through inhaling dried particles from an infected bird's feces, respiratory secretions, or feather dust. Immunocompromised individuals, pregnant women, and the elderly face higher risk and should avoid contact with a bird undergoing testing or treatment.
How long does chlamydiosis treatment take in cockatiels? Treatment requires a minimum of 45 days of doxycycline. This duration is non-negotiable; shorter courses commonly result in relapse and continued shedding. The bird must be retested after the full course is complete to confirm clearance. During treatment, the bird should be isolated from other birds and the environment cleaned thoroughly.
How much does chlamydiosis testing and treatment cost for a cockatiel? An avian vet exam typically runs $100–200. PCR testing costs $80–150. A 45-day doxycycline course runs $50–150 in medication costs depending on formulation. If follow-up bloodwork and retest are included, total costs typically reach $300–600 per bird. Treating multiple birds in a household multiplies this cost proportionately.
How do I know if my cockatiel's droppings look abnormal? Normal cockatiel droppings have three parts: dark solid feces, white or cream urates, and clear liquid urine. With chlamydiosis, the urate portion turns lime-green or yellow-green. Watch for overall color change to greenish-brown or watery consistency. Photograph droppings on white paper towel and bring the photo to your vet appointment.
Can cockatiels recover from chlamydiosis completely? Yes. With a full 45-day course of appropriate antibiotic therapy, most cockatiels recover completely and clear the infection. Post-treatment PCR testing confirms clearance. Without treatment, chronically infected birds serve as silent reservoirs, periodically shedding the organism and infecting both other birds and people in the household.
Still Not Sure if Your Cockatiel Needs a Vet?
When you're not sure if this is wait-and-see or call-tonight, Voyage AI Vet triages in under 2 minutes. Describe what you're seeing in chat, share photos of your cockatiel's droppings on a white paper towel and the bird's posture and breathing pattern, or hop on a live video call if you want a second pair of eyes. Every answer comes with citations to the actual veterinary literature it's pulling from — so you see exactly where the guidance comes from, not just a chatbot's word.