Farm Animals

Sheep Ovine Pulmonary Adenocarcinoma Management

Ovine pulmonary adenocarcinoma (OPA) is a contagious lung cancer caused by Jaagsiekte sheep retrovirus. It causes progressive respiratory failure and has significant welfare implications.

Key Facts

OPA is caused by Jaagsiekte sheep retrovirus (JSRV) transmitted through respiratory secretions
Affected sheep develop progressive respiratory distress over weeks to months
The wheelbarrow test (raising hindquarters) demonstrates fluid draining from nostrils in advanced cases
There is no vaccine or treatment and the disease is always fatal
Culling infected sheep and rigorous biosecurity are the only control measures available

Welfare Considerations

OPA causes prolonged suffering through progressive breathlessness, weight loss and debilitation. Early identification and humane slaughter of affected animals is essential to minimize suffering duration. Flock screening, closed flock policies and purchasing stock from OPA-free flocks are important preventive welfare measures for producers.

What You Can Do

Monitor sheep for chronic cough, weight loss and increased respiratory rate
Perform the wheelbarrow test if OPA is suspected and seek veterinary confirmation
Cull confirmed OPA cases promptly to prevent suffering and spread
Purchase replacement sheep from accredited OPA-monitored flocks
Implement closed flock policies and quarantine new arrivals before integration