Ornithosis in pigeons is a respiratory infection caused by Chlamydia psittaci. The earliest signs are often subtle: a slight clear or watery discharge from the eyes or nostrils, mild sneezing, and a bird that seems a little less eager for food. Because these first symptoms are easy to miss, many cases are only noticed when the infection has progressed. Recognising ornithosis in pigeons symptoms early gives your vet the best chance to help your bird and protect the rest of your loft.

What Is Ornithosis and How Common Is It?

Ornithosis, also called chlamydiosis or psittacosis, is a bacterial infection that affects the respiratory tract, eyes, and sometimes the liver and spleen of pigeons. It is caused by Chlamydia psittaci, an organism that can survive in the environment for short periods but is mainly spread bird-to-bird. The MSD Veterinary Manual notes that pigeons and other birds can carry the bacteria without showing obvious signs, which makes control challenging.

The infection is common in pigeon lofts worldwide, especially where birds are stressed by overcrowding, poor ventilation, or concurrent infections. Young birds, newly acquired pigeons, and those recovering from other illnesses are most vulnerable. Because it can also affect humans (as a zoonosis), recognising the signs and seeking veterinary advice is important for both your birds and your family.

Early Symptoms of Ornithosis in Pigeons

The first signs are often respiratory and ocular. You may notice a clear or slightly cloudy discharge from one or both eyes, or a small amount of moisture around the nostrils. Sneezing may be occasional at first, then become more frequent. Some birds develop a mild conjunctivitis that looks like a "one eye cold," which is a common nickname for the condition. These early symptoms can be mistaken for dust irritation or a minor chill, so it pays to observe your birds closely during routine checks.

As the infection takes hold, additional symptoms appear. The discharge may become thicker and yellowish. Breathing may become laboured, especially after exercise, and you might hear a faint click or rattle when the bird breathes. Some pigeons lose interest in food and drink less water. Weight loss follows if the bird does not eat enough. In some cases, the infection spreads to the liver, causing a greenish tinge to the droppings.

Progressive and Secondary Signs

If left untreated, ornithosis can lead to more serious problems. The bird may develop a swollen, reddened eye that stays partially closed. Nasal discharge can become thick and block the airways. Breathing may be accompanied by a tail bob or open-mouth breathing, especially in young birds. The pigeon may become dull, sit fluffed up on the perch, and show reduced appetite. In severe cases, the infection can cause diarrhoea, dehydration, and even death, particularly in nestlings or immunocompromised adults.

Because ornithosis often occurs alongside other respiratory pathogens such as Mycoplasma or secondary bacteria, the signs can overlap. This is why laboratory testing is sometimes needed to confirm the diagnosis. Your veterinarian may take swabs from the eye, nose, or throat, or collect a blood sample to detect antibodies.

How Ornithosis Spreads in a Loft

The bacteria are shed in nasal and eye secretions, as well as in droppings and sometimes in the crop. Birds can inhale contaminated dust or droplets, or ingest the organism from contaminated food and water. Close contact between pigeons in a confined loft makes transmission easy. The infection can also pass from parent to chick during feeding. Stressful events such as racing, training, or transport can trigger shedding in carrier birds and lead to an outbreak.

Because the bacteria can survive in dried droppings and dust, cleaning and ventilation are important. However, the organism is susceptible to many disinfectants. Your veterinarian can advise on appropriate cleaning protocols for your loft.

Recognising Ornithosis: A Quick Checklist

Use this checklist to note any signs you see. It is not a diagnosis, but it will help you describe your observations to your vet.

• Clear or watery eye discharge, sometimes only in one eye
• Sneezing or nasal discharge
• Mild conjunctivitis (red, irritated eyes)
• Reduced appetite or weight loss
• Laboured breathing or tail bobbing after exercise
• Clicking or rattling sounds when breathing
• Lethargy, fluffed-up appearance
• Greenish or loose droppings (in later stages)

Veterinary Diagnosis and Treatment Options

There is no substitute for a veterinary diagnosis. Your vet will consider the history, clinical signs, and possibly laboratory tests. Because ornithosis is caused by a bacteria, treatment typically involves antibiotics. The choice of antibiotic depends on the severity of the infection, the bird's overall health, and whether other pathogens are involved. Your veterinarian may prescribe a tetracycline-class antibiotic, which is commonly used for this condition. In some cases, a combination of antibiotics may be needed.

You may hear terms like "ornithosis treatment" or "one eye cold treatment" in pigeon-keeping circles. Treatment should always be guided by a veterinarian who can examine your bird and determine the most appropriate approach. The products available in our Pigeon Antibiotics collection are meant to be used under veterinary guidance. They include:

• Doxybird Tabs (Medpet) – formulated for ornithosis and one eye cold in pigeons. This is a prescription-only product in many regions, and it requires veterinary oversight.
• Tylodox (Medpet) – used for mycoplasmosis, ornithosis, and chlamydia in pigeons. It combines two antibiotics and should only be used under veterinary direction.
• Tylosin Powder (Generic) – CRD Treatment for Pigeons & Pet Birds (Tylosin Tartrate 99%) – often used for respiratory infections in birds. It must be prescribed by a vet who can determine if it is appropriate for your bird.
• Amoxicillin 10% Powder for Birds – Broad-Spectrum Support for Pigeons & Pet Birds – 100 g – a broad-spectrum antibiotic that may be used for secondary bacterial infections. Again, veterinary guidance is essential.

Your veterinarian will decide which product, if any, is suitable for your pigeon. Do not use any medication without a prescription and professional advice. The product label and your vet's instructions are the only sources you should follow.

Supportive Care and Prevention

Alongside veterinary treatment, supportive care can help your pigeon recover. Provide a clean, quiet, well-ventilated environment. Reduce stress by keeping the bird away from noisy areas and limiting handling. Ensure easy access to fresh water and food. Your vet may recommend nutritional support or fluids if the bird is dehydrated.

Prevention focuses on good loft management. Quarantine new birds before introducing them to the flock. Maintain good ventilation to reduce dust and ammonia levels. Clean and disinfect feeders and drinkers regularly. Avoid overcrowding. Keep stress to a minimum, especially during racing season. If you notice any signs of illness, isolate the affected bird and contact your vet.

When to Call Your Vet

Call your veterinarian immediately if you observe any of the following red-flag signs:

• Open-mouth breathing or severe difficulty breathing
• Complete loss of appetite for more than 24 hours
• Significant weight loss or emaciation
• Persistent diarrhoea or blood in droppings
• Swelling around the eyes or face
• Sudden death in the loft
• Signs that worsen despite supportive care

Early intervention is key. Ornithosis can be managed effectively when diagnosed and treated promptly under veterinary supervision.

Frequently asked questions

Can ornithosis in pigeons be cured?

Yes, ornithosis can be treated successfully with appropriate antibiotics prescribed by a veterinarian. Recovery depends on early diagnosis and supportive care. Some birds may remain carriers, so follow-up testing and loft management are important.

Is ornithosis contagious to humans?

Yes, ornithosis (psittacosis) is a zoonotic disease, meaning it can spread from birds to humans. People with weakened immune systems are at higher risk. Practise good hygiene, wear gloves when cleaning, and consult a doctor if you develop flu-like symptoms after handling sick birds.

What is the difference between ornithosis and one eye cold?

"One eye cold" is a common term for the mild conjunctivitis often seen in the early stages of ornithosis. However, not all one eye colds are ornithosis; other bacteria or irritants can cause similar signs. Veterinary testing is needed to confirm the cause.

How can I prevent ornithosis in my loft?

Prevention includes quarantining new birds, maintaining good ventilation, avoiding overcrowding, cleaning and disinfecting regularly, and minimising stress. If an outbreak occurs, work with your vet to isolate and treat affected birds and review loft hygiene.

Are antibiotics for ornithosis available over the counter?

In many regions, antibiotics for pigeons require a veterinary prescription. Even where they are available over the counter, using them without veterinary guidance can be ineffective or harmful. Always consult a vet for diagnosis and treatment.

Products mentioned in this guide

• Tylosin Powder (Generic) – CRD Treatment for Pigeons & Pet Birds (Tylosin Tartrate 99%) — from $69.95 (Antibiotic)
• Amoxicillin 10% Powder for Birds – Broad-Spectrum Support for Pigeons & Pet Birds – 100 g — from $59.99 (Antibiotic)
• Doxybird Tabs (Medpet): Treats Ornithosis / One Eye Cold in Pigeons — from $39.95 (Respiratory Treatment)
• Tylodox (Medpet) Effectively Treats Mycoplasmosis, Ornithosis & Chlamydia in Pigeons — from $49.95 (Respiratory Treatment)

Browse all Pigeon Antibiotics →

Sources and further reading

General veterinary background for this article:

• MSD Veterinary Manual
• Merck Veterinary Manual
• American Veterinary Medical Association
• FDA Center for Veterinary Medicine
• World Organisation for Animal Health
• Association of Avian Veterinarians

A note on veterinary advice

This article is general educational information about animal health products and is not veterinary advice. It does not contain dosing instructions. Always consult a licensed veterinarian before starting, stopping, or changing any medication or supplement for your animal. Medications for animals should never be used by humans.