Infectious Laryngotracheitis (ILT) in Poultry

The disease is caused by Gallid herpesvirus commonly known as infectious laryngotracheitis virus. Virus grow rapidly in chicken embryo but is destroyed fast in the environment outside horizonal transmission of the virus is through feeding tools, feed, drinking water.

1. Etiology
The disease is caused by Gallid herpesvirus commonly known as infectious laryngotracheitis virus .
Virus grow rapidly in chicken embryo but is destroyed fast in the environment outside horizonal transmission of the virus is through feeding tools, feed, drinking water.
2. Symptoms
The respiratory signs may include gasping, coughing, rales, with expulsion of caseous matter, eye discharge mucoid nasal discharge, extension of the neck during inspiration, anorexia, slow weight gain ruffled feathers. If it is co-inffected with bacterria asociated with coughing, the disease will be severe and prolonged, use of antibiotics for treatment of coughing is not effective, later, affected chickens express diarrhea, drinking a lot of water, drop in egg production in laying hens, especially oral discharge with bloody purulent fluid runing down to the floor and vehicles.
3. Lesions
Lesions are restricted to the trachea, excepting co- infection with bacteria (Mycoplasma, E.coli). In Ininitial stage, the disease lasts 1-3 days. In a trachelectomy, on the tracheal mucosa, haemorrhagic tracheitis in red colour may be seen. In windpipes, bloodstained mucus is evident.
After 4-7 days mucosal lesions in the trachea and larynx epithelial cell sloughing llke caseous matter then becomes long clot to obstruct the airways.
Air sacs can become inflamed if the infection is prolonged and there are concurent infecttions of Mycoplasma, E. coli. If infected with a low virulent strain, congestion of trachea, swelling of conjunctiva, eye swelling caused by sinus congestion, nasal swelling may be seen.

4. Prevention
- Hygiene: Keep animal houses, pens, feed throughs and drinking water clean, periodically disinfection
- Increasing resistance of poultry by adding electrolytes, B-complex, and various types of Premix ...
- MAR-ND vaccine is given
+ In the first time, MAR-ND / IB.VAC vaccine is given by mouth or by eye drop to the chickens at 3 days of age.
+ In the second time MAR-ND / IB.VAC vaccine is administered by nose, eye drop or by mouth in chickens at 17 days of age.
5. Treatment
The disease caused by a virus, there is no cure, only prevention by vaccination when a epidemic occurs in chicken, ILT vaccine should be administered by drop to chickens in the epidemic with double dose, then broad-spectrum antibiotics are administered against secondary infections such as E.coli, pullorum disease, coughing, coccidiosis. and a good tonic drug to raise the resistance of the chickens to viruses. Use one of the highly effective treatments as follows:
Regimen 1: DOXY-TYLAN is administered in combination with 39 VITA-AMIN
Regimen 2: Use DOXY50% is administered in combination with HERBAL MARPHASOL
Regimen 3: COLI 102 is administered in combination with 39-VITA-A

(Translated by Dr. Pham Duc Chuong, R & D Dept, Marphavet Corp)

Author: Tran Tuyen
Source: Marphavet