Laryngotracheitis of Fowl

an acute viral disease of chickens (less often, of pheasants and turkeys), characterized by inflammation of the mucosae of the larynx and trachea, difficult breathing, hoarseness, and, often, conjunctivitides.

Laryngotracheitis of fowl is distributed on all continents and causes considerable economic damage (mortality, 15–50 percent; egg yield in surviving fowl decreased by 10–30 percent). Both infected and recovered chickens are sources of the causative agent. Infection occurs through the respiratory tract. Treatment has little effect. A recovered bird acquires prolonged immunity. Laryngotracheitis of fowl is prevented by observing proper sanitation in the care and maintenance of the birds and by vaccination.