Laryngotracheitis (LT) can be devastating to poultry flocks. But, with proper biosecurity measures in place, LT virus can be prevented and controlled.

LT is a highly contagious viral infection caused by the herpes virus, resulting in respiratory disease in chickens, turkeys, pheasants and some other species of birds.  It’s a respiratory disease that usually kills 10-20% of infected birds but mortality can run as high as 70%.  This can be economically devastating.


Clinical signs of LT virus can begin to appear within six to 12 days after exposure. Poultry, regardless of mild or severe infections, experience decreased growth, failure to thrive and decreased egg production.
Mild infection symptoms include:

  • Swollen, watery eyes
  • Swollen sinuses
  • Persistent watery or mucoid nasal discharge
  • Low mortality (0.1-2%)

Severe symptoms include:

  • Labored, open-mouthed breathing
  • Sneezing
  • Violent coughing often accompanied by bloody mucus
  • 5-70% mortality, average mortality rate 10-20%

Most birds recover within 10-14 days.

How LT Virus Spreads

Infected birds become life-long carriers of the virus and can shed the virus during times of stress, infecting other birds. Multi-age laying farms are most susceptible with high potential to spread the virus from older infected flocks to younger vulnerable flocks. Birds are most contagious when showing clinical signs of the virus.

In addition to infected birds shedding the virus, lax biosecurity such as transporting infected birds and contaminated clothing, footwear, vehicles, equipment, and litter can also spread the virus.

Preventing and Controlling LT Virus

While there is not one effective treatment against LT virus, birds – especially layers – can be vaccinated as a control measure. However, vaccinating broilers isn’t routine since it can also increase upper respiratory problems. Rigorous biosecurity measures are the best way to prevent transmission of the virus by reducing exposure. LT virus is an enveloped virus and is vulnerable to disinfectants. Disinfectants are EPA-regulated, and it is incredibly important to use chemistries proven to inactivate LT virus as part of a thorough biosecurity program.

Effectively controlling pathogens at the line of separation into houses is important because employees and visitors can introduce the virus via footwear and clothing. FortiGuard is an EPA -registered solid foot pan sanitizer designed to enhance biosecurity as your last line of defense against harmful pathogens such as LT virus.



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