Infectious Coryza

Infectious Coryza is caused by the bacterium Haemophilusparagallinarum and is seen especially in multi-age farms that are never depopulated. Morbidity is high but mortality low if uncomplicated although it may be up to 20%.

The route of infection is conjunctival or nasal with an incubation period of 1-3 days followed by rapid onset of disease over a 2-3 day period with the whole flock affected within 10 days, resulting in increased culling. Carriers are important with transmission via exudates and by direct contact. It is not transmitted through eggs.

The bacterium survives 2-3 days outside the bird but is easily killed by heat, drying and disinfectants. Intercurrent respiratory viral and bacterial infections are predisposing factors.

The clinical signs in Infectious Coryza are Facial swelling, Purulent ocular and nasal discharge, Swollen wattles, Sneezing, Dyspnoea, Loss in condition, Drop in egg production, Inappetance.

Disease will be prevented by Vaccination and practice of all-in, all-out management and controlled by antibiotics and Vitamins/ Mineral supplements.