Infectious Laryngotracheitis in Chickens: Symptoms & Care Guide

Chickens can suffer from infectious laryngotracheitis (ILT), a contagious respiratory disease caused by a herpesvirus known as Gallid alphaherpesvirus 1. This virus infects the upper respiratory tract, primarily the larynx and trachea, causing inflammation and discomfort that can threaten the bird's life if untreated.

What is Infectious Laryngotracheitis?

ILT is a highly contagious disease spread mainly through inhalation or ingestion of viral particles shed by infected birds. It can also spread mechanically via contaminated equipment, clothing, and footwear. Recovered birds may become lifelong carriers, intermittently shedding the virus and risking new outbreaks, particularly when stressed. The virus causes inflammation in the windpipe (trachea), leading to breathing difficulties, coughing, and sometimes bloody mucus obstructing the airway.

Recognising the Symptoms of ILT

Early detection is vital for managing ILT effectively. Watch for these key signs in your chickens:

• Difficulty breathing (dyspnoea) and gasping for air, often mistaken for gape worm infestation.
• Coughing, sometimes accompanied by bloody mucus or plugs.
• Discharge from the eyes and nose, including conjunctivitis and sinusitis.
• Reduced egg production and lethargy.
• Swollen sinuses and respiratory noises such as wheezing or gurgling.

Severe cases can cause blood clots in the trachea that may lead to suffocation if not cleared.

Diagnosing Infectious Laryngotracheitis

Definitive diagnosis typically involves veterinary examination and laboratory testing. Vets may observe blood clots in the windpipe during examination, and in some cases remove them to prevent suffocation. Molecular tests like PCR can detect viral DNA. Often, biopsy or post-mortem histopathology reveals characteristic lesions such as intranuclear inclusion bodies.

Treatment Options for ILT

Since ILT is caused by a virus, antibiotics cannot clear it. However, antibiotics may be prescribed to prevent or treat secondary bacterial infections, common in afflicted birds. Anti-inflammatory medications may help alleviate breathing discomfort. Quarantining infected birds to reduce spread and providing a stress-free environment aid recovery.

For small flocks, eye drop vaccines are available, but require careful administration and consultation with a vet. These vaccines do not always prevent virus shedding but can reduce clinical severity.

Managing and Living with ILT

Because infected chickens become lifelong carriers, it is essential to manage their environment carefully:

• Maintain good ventilation in chicken housing year-round to reduce viral spread.
• Keep infected or recovered birds isolated from healthy ones.
• Clean and disinfect housing thoroughly using poultry-safe disinfectants capable of eliminating herpesviruses — your vet can recommend suitable products.
• Reduce stressors such as sudden changes, overcrowding, and extreme temperatures.
• Vaccinate larger flocks appropriately to reduce outbreaks and economic losses.

6 Ways to Protect Your Chickens from ILT

1. Ensure adequate ventilation in coops to prevent virus build-up.
2. Limit visitor access and disinfect footwear and equipment.
3. Quarantine new or returning birds before introducing to your flock.
4. Maintain hygiene by regular cleaning and disinfection of housing.
5. Consult your vet for vaccination options and early diagnosis.
6. Manage stress with consistent routines and proper nutrition.

Symptoms of infectious laryngotracheitis in chickens

Infectious laryngotracheitis (ILT) is a highly contagious respiratory disease caused by Gallid herpesvirus 1. Clinical signs range from mild to severe depending on the strain and the immune status of the flock. In severe outbreaks, the hallmark sign is bloody mucus — affected birds stretch their necks and cough or gasp, sometimes expelling blood-tinged discharge. In milder forms, signs may be limited to watery eyes, nasal discharge, rattling breathing, and a drop in egg production. Mortality in acute outbreaks can be significant. Birds that recover become lifelong carriers and can shed virus during stress, representing an ongoing risk to unvaccinated birds. Diagnosis is confirmed by laboratory testing, particularly PCR.

How ILT spreads and how to prevent it

ILT spreads rapidly through direct contact between birds, airborne particles, contaminated equipment, litter, and clothing. Wild birds can carry and introduce the virus to domestic flocks. The virus is relatively fragile in the environment and is inactivated by standard disinfectants, but it can persist in secretions for several days. Prevention for small backyard flocks centres on strict biosecurity: quarantining new birds for a minimum of three weeks before introducing them to the existing flock, preventing contact with wild birds where possible, and cleaning and disinfecting housing thoroughly after any respiratory illness. For flocks at higher risk — particularly those in areas with known disease or a history of ILT on the premises — vaccination is a practical control measure.

Managing and treating ILT in chickens

There is no specific antiviral treatment for ILT. Management focuses on supportive care, biosecurity, and vaccination. Affected birds may benefit from reducing stress, providing warm dry housing, and ensuring access to water. In an active outbreak, birds in severe respiratory distress are unlikely to recover and humane culling should be considered. Vaccination is the primary control tool: live attenuated vaccines are effective but must be used carefully — live ILT vaccines contain a weakened form of the virus that can in some circumstances spread to unvaccinated birds. Vaccination is most appropriate for flocks at genuine risk, in areas with known disease, or on premises with a history of outbreaks. Any suspected ILT outbreak should be reported to your vet promptly.

Related articles

• Fancy pigeon breeds
• Can Puppies Eat Chicken?
• Duck breeds

Final thoughts on infectious laryngotracheitis

Infectious laryngotracheitis is a serious respiratory condition in chickens caused by a herpesvirus that can severely impact bird health and production. Early recognition of symptoms, good biosecurity practices, veterinary care, and careful flock management are key to minimising the risks and effects of ILT. While viral infections are challenging, a well-informed, empathetic approach ensures your chickens get the best chance of recovery and long-term health.

Controlling and preventing ILT in backyard flocks

ILT spreads through direct contact with infected birds, respiratory secretions, contaminated equipment, and potentially via airborne transmission over short distances. Biosecurity is the first line of defence: keeping new birds in strict quarantine for at least 30 days before mixing with your existing flock is essential. Equipment, clothing, and footwear used in infected premises should be thoroughly disinfected before use elsewhere, as the herpesvirus can survive in the environment for several weeks under suitable conditions.

Vaccination is available in the UK and provides good protection for commercial and larger backyard flocks in high-risk areas. However, it is important to understand that ILT vaccines are themselves live attenuated viruses and can in rare circumstances cause clinical disease or spread to unvaccinated birds. The decision to vaccinate should be made in consultation with a poultry vet who can assess the risk to your specific flock. There is no specific treatment for established infection; supportive care and prompt culling of severely affected birds are the main responses once an outbreak is confirmed.