OPA sheep

Pathogen

·    Beta retrovirus

Infection and transmission

·    Virus infects cells in lungs ® replaces normal tissue with tumours ® produce white foamy fluid

·    Transmission: aerosol, colostrum/milk, via infective tumour fluid, virus survives weeks in environment

Clinical signs

·    Weight loss

·    Increased RR and effort

·    Cough

·    Nasal discharge

·    Sudden death

Diagnosis

·    Thoracic U/S looking for pulmonary tumours

·    PM to d/dx

Treatment

·    None

Prevention

·    Only buy from trusted sources

·    Increase boundary biosecurity

·    U/S lungs for tumour

·    Identify and cull infected offspring

·    Keep in single age groups – keep young away from adults

·    Reduce stocking density ® reduces close contact

·    Snatch lambing