Respiratory disease is most common and causes '''tachypnoea, nasal discharge, dyspnoea, sneezing, abnormal breathing'''.
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'''Decrease in egg production''' and reproductive failure. Folded egg membranes and egg peritonitis may develop.
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Clinical disease is usually accompanied by a '''decrease in egg production''' and reproductive failure. Folded egg membranes and egg peritonitis may develop consequentially.
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'''Torticollis''', reluctance to move, swelling of the head, face and eyes, head shaking.
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'''Torticollis''', reluctance to move, swelling of the head, face and eyes and head shaking are manifestations of more severe cases.
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'''Lack of growth''' and retardation will occur in young birds infected by TRV.
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'''Lack of growth''' and retardation.
==Diagnosis==
==Diagnosis==
Serological diagnosis can be achieved by '''[[ELISA testing | ELISA]]'''.
Serological diagnosis can be achieved by '''[[ELISA testing | ELISA]]'''.