Rigorous measures needed for effective control of OPA

摘要

Ovine pulmonary adenocarcinoma (OPA) is an infective lung tumour caused by the Jaagsiekte virus. It can be difficult to diagnose and has no treatment, making it a challenge to control once it takes hold within a flock.The virus is mostly spread by secretions from the nose and mouth, but it can also be passed from ewes to lambs via milk and colostrum. It can survive in buildings for up to two months, so sheep can pick it up from the environment, particularly feed troughs.It typically takes between three and four years for an infected animal to show symptoms, by which time they are likely to have spread the disease to several others within the flock. So this makes disease prevention vital.