Ovine Pulmonary Adenocarcinoma: Welfare Implications in Sheep Flocks

Ovine pulmonary adenocarcinoma (Jaagsiekte) is a contagious lung tumour disease of sheep causing progressive welfare deterioration and no treatment options.

Key Facts

Jaagsiekte is caused by Jaagsiekte sheep retrovirus and is a contagious tumour of sheep
Clinical signs including weight loss, respiratory difficulty, and nasal fluid production develop over months
Affected sheep adopt a characteristic 'wheelbarrow' position to drain fluid from the chest
There is no treatment; affected animals should be culled humanely when welfare is compromised
Purchased sheep represent the primary route of introduction into naive flocks

Welfare Considerations

Ovine pulmonary adenocarcinoma causes progressive welfare deterioration over an extended period. The growing tumour mass occupies lung tissue, causing progressive dyspnoea as less functional lung remains. Fluid accumulation in the chest causes further respiratory compromise. Affected sheep lose condition progressively while continuing to eat. The obvious welfare compromise of severe respiratory difficulty and emaciation in late-stage disease makes prompt culling an ethical imperative when clinical signs are apparent. The insidious onset means welfare compromise is occurring for weeks to months before obvious signs prompt action. Early identification of affected sheep through regular health monitoring and prompt humane culling prevents prolonged suffering.

What You Can Do

Test purchased sheep for Jaagsiekte before introduction to naive flocks where possible
Monitor sheep health regularly to identify early respiratory disease signs
Cull clinically affected Jaagsiekte sheep promptly rather than allowing prolonged deterioration
Implement biosecurity measures to prevent introduction of retrovirus-affected animals