Systematic Veterinary Virology

SYMPTOMS

• The infection in young chickens is characterised by gasping, coughing and nasal discharge with wet eyes and swollen sinuses. The chicks appear depressed and may huddle near the heat source. Food consumption and weight gain are also reduced.
• In adult laying flocks, the respiratory symptoms of gasping and coughing are usually followed by a drop in production and the birds may molt. Pullets in good condition may suffer only a slight drop in production and regain normal production within few weeks.
• Following the decline, production of misshapen soft-shelled eggs with inferior internal quality is often observed. This change in shell and internal quality may be permanent. Secondary bacterial infection due to E.coli complicates the disease scenario and lead increased condemnation of birds.