2-Infectious laryngotracheitis (ILT) It is acute viral respiratory disease of primarily chickens and pheasants. Etiology: herpesvirus Clinical Signs: ILT virus has 2 forms: A-Epizootic acute form: it characterized by 1-Eye and nasal discharge. 2- Moist rales, gasping and coughing. 3-Expectoration of bloody exudate or mucus tinged with blood.
4-Drop of egg production reach to 40% 5-Mortality is 10- 20%. B-Enzootic mild form: it characterized by 1-Unthriftiness. 2-Drop in egg production. 3-Watery eye and nasal discharge. 4-Swollen of orbital sinuses. 5-Mortality rate is 5%.