Clinical manifestations of respiratory infectious bronchitis

The incubation period is 36 hours or longer. It spreads quickly among chickens, has an acute onset, and has a high incidence rate. Chickens of all ages can be infected, but chicks aged 1 to 4 days are the most serious, with high mortality. As age increases, resistance increases and the condition becomes less severe.

Sick chickens have no obvious early symptoms. They often become ill suddenly and develop respiratory symptoms, which quickly spread to the entire flock.

Characteristics: breathing with mouth and neck stretched, coughing, serous or mucus secretions from the nasal cavity. The wheezing sound is especially obvious at night. As the disease progresses, the systemic symptoms worsen, manifested as listlessness, loss of appetite, loose feathers, drooping wings, lethargy, fear of cold, and individual chickens’ sinuses are swollen and tearful. thin.

Young chickens exhibit sudden rales, followed by difficulty breathing, sneezing, and rarely nasal discharge.

The respiratory symptoms of laying hens are mild, and the main manifestations are reduced egg-laying performance, the production of deformed eggs, sand-shell eggs, soft-shell eggs, and discolored eggs. The eggs are as thin as water, and there is lime-like material deposits on the surface of the egg shells.