Infectious Laryngotracheitis in Poultry: Welfare and Control

ILT causes severe, distressing respiratory disease in chickens with characteristic bloody mucus production — vaccination and biosecurity are essential welfare tools.

Key Facts

• ILT is caused by Gallid herpesvirus 1, causing acute respiratory distress in unvaccinated flocks
• Affected birds show gasping, neck extension, and blood-streaked mucus from severe tracheal inflammation
• Mortality can reach 70% in severe outbreaks without vaccination
• Recovered birds remain latent carriers and can trigger outbreaks in naive birds under stress
• Live attenuated vaccines via drinking water or eye-drop are effective preventive tools

Welfare Considerations

ILT causes one of the most welfare-distressing respiratory presentations in poultry: severely affected birds gasp for breath with their heads extended and beaks open, expelling bloody mucus as inflamed tracheal tissue sloughs. The distress of severe oxygen deprivation, hemorrhagic airways, and the struggle to breathe represents acute and significant suffering. Flock-level mortality in unvaccinated birds during outbreaks can be catastrophic. Welfare management requires rapid isolation and depopulation of severely affected flocks, emergency vaccination of at-risk surrounding flocks, and strict biosecurity to prevent spread via equipment and personnel. Prevention through vaccination programs is far superior to treating outbreaks after they begin.

What You Can Do

• Vaccinate all chicken flocks in endemic areas using licensed ILT vaccines
• Isolate any birds showing severe respiratory signs immediately to prevent flock spread
• Report suspected ILT to your veterinarian immediately — outbreak control prevents large-scale suffering
• Maintain strict biosecurity including equipment disinfection and visitor restrictions during outbreaks
• Source replacement birds from known ILT-free flocks to prevent introduction to naive populations