Infectious Laryngotracheitis (ILT): The Respiratory Nightmare in Poultry

Introduction

​Infectious Laryngotracheitis (ILT) is a viral respiratory infection of chickens caused by the Gallid alphaherpesvirus 1. The infection is characterized by severe breathing difficulties in infected birds. For poultry stakeholders, the outbreak of this disease in a farm means not only the death of birds but also the contamination of the environment.

​Transmission and Latency

​The mode of transmission of the virus:

The virus is spread through respiratory secretions/droplets.

​The "Carrier" Problem:

One of the most unique features of this virus is that recovered birds can act as subclinical carriers. The virus remains "hidden" in the nervous system of recovered birds. During stressful periods, the virus re-emerges in these birds, infecting other healthy flocks of birds.

​The "Pump-Handle" Breathing:

The most evident signs of the infection:

​Gasping & Dyspnea:

The infected birds stretch their necks forward and upward to take in air.

​Blood-Stained Mucus:

Blood-stained mucus can also be found on the walls of the poultry farm or on the feathers of the infected birds.

​Expectoration of Blood:

Severe cases of the infection, known as Velogenic, cause birds to cough up clotted blood.

​Conjunctivitis:

The eyes of infected birds are swollen and watery. Their eyes are almond-shaped.

​Post-Mortem Findings

​The veterinarian can observe:

​Tracheal Plugs:

The windpipe of the infected bird is clogged with blood clots or yellowish cheesy material (caseous exudate), which causes death.

​Hemorrhagic Laryngitis:

The larynx of infected birds has severe hemorrhages.

​Prevention and Control

​Since it’s a Herpesvirus, bio-security is everything:

​Vaccination:

The use of Tissue Culture Origin (TCO) or Chicken Embryo Origin (CEO) vaccines.

​Quarantine:

No mixing of birds of different ages.

​Sanitation:

The sheds should be disinfected with a virucidal agent.