Conjunctivitis

Conjunctivitis is inflammation of the conjunctiva, the thin pink membrane lining the inside of the eyelids and the front of the eye. It is common in birds and sometimes harmless, but just as often it is the first visible sign of another disease, particularly a respiratory one. So it should not be ignored even when it seems mild.

The conjunctiva reacts with inflammation to anything that irritates or infects it. In birds the eye is closely connected to the nasal cavities and sinuses, so inflammation easily spreads from the airways to the eyes and vice versa.

The most common causes:

• Bacteria – especially when the bird is weakened or lives in unclean conditions.
• Mycoplasma – very common in poultry, pigeons and some songbirds (e.g. finches). Besides the eyes, they often affect the respiratory system too.
• Chlamydia – in parrots and pigeons, eye inflammation can be a sign of psittacosis or ornithosis.
• Irritants – dust from bedding, smoke, sprays, air fresheners, harsh cleaning products.
• Draughts and cold – a bird placed next to an open window or air conditioner.
• Vitamin A deficiency – common in parrots fed only seeds; the mucous membranes become sensitive and prone to inflammation.
• A foreign body or scratch – a seed husk, a splinter, an injury from another bird.

Infectious forms spread to other birds through direct contact, shared water and food bowls, and airborne droplets.

The changes are usually clearly visible on the eye itself:

• redness and swelling of the eyelids and conjunctiva
• watering eyes, a watery or thick, yellowish discharge
• wet, matted or dirty feathers around the eye
• the bird squints, keeps the eye half-closed or does not open it
• rubbing its head on the perches or cage bars
• the eye may look cloudy or watery

If the cause is an infectious disease, general signs often appear as well: lethargy, apathy, loss of appetite and interest in surroundings, and with mycoplasma and chlamydia also sneezing, nasal discharge and wheezing or difficulty breathing. Inflammation of only one eye more often points to an injury or foreign body, while both eyes being inflamed suggests an infection or an irritant in the environment.

Don't wait if you notice:

• a swollen eye that the bird does not open at all
• a thick, yellow or greenish pus-like discharge
• clouding or a white spot on the eye itself (the cornea)
• sneezing, nasal discharge, wheezing or open-beak breathing at the same time
• a fluffed-up, sleepy bird that is not eating
• inflammation spreading to several birds in the flock or aviary
• a condition that does not improve within a day or two

The vet examines the eye under magnification and may stain it with a special dye (fluorescein) to check for damage to the cornea. They take a swab of the conjunctiva to test for bacteria, mycoplasma or chlamydia. They also assess the bird's general condition, respiratory system and diet, as treatment depends on these.

Treatment depends on the cause and is always decided by the vet:

• for a bacterial infection the vet prescribes antibiotic eye drops or ointment and, if needed, an oral medicine
• mycoplasma and chlamydia require a longer course of antibiotics prescribed by the vet, often for the whole flock
• for vitamin A deficiency the vet recommends a change of diet and, if necessary, prescribes a vitamin supplement
• irritation from the environment is resolved by removing the cause

Do not put human eye drops or leftover old medicines in the bird's eye yourself. Some products, especially those containing corticosteroids, can seriously worsen an infection or damage to the cornea.

• Separate the sick bird from the others in a quiet, warm, draught-free room.
• Remove possible sources of irritation: smoke, sprays, scented candles, dusty bedding.
• You can gently wipe discharge off the feathers around the eye with clean gauze moistened with lukewarm boiled water, using a fresh piece of gauze for each eye. Do not rub the eye itself.
• Wash and refill the food and water bowls every day.
• Wash your hands after handling the sick bird, before you touch other birds.

Caution: if the cause is chlamydia (psittacosis or ornithosis), the disease can be passed to people. Clean the cage wearing gloves, moisten dry droppings before cleaning so no dust is raised, and if you develop flu-like symptoms, see a doctor and tell them you have a sick bird.

If you have found a wild bird with inflamed eyes, hand it over to a rescue centre or a vet. Wild birds in Croatia are protected and may not be kept at home long-term.

• A varied diet: for parrots, pellets alongside seeds, plus vegetables rich in beta-carotene (carrots, sweet potato, dark green leafy vegetables).
• A clean cage and bowls, regular changes of bedding.
• Good ventilation, but no draughts.
• No smoke, aerosols or strong scents in the room with the birds.
• Keep new birds separate (quarantine) for a few weeks before introducing them to the others.

Conjunctivitis in birds responds well to treatment when the cause is found in time. Eye inflammation is often just the visible part of a bigger illness, so besides redness and discharge, keep an eye on the bird's breathing, appetite and behaviour. If it does not improve quickly, see a vet.