Respiratory disease is one of the leading causes of morbidity and mortality in sheep, causing significant welfare harm and economic loss. It is particularly prevalent in housed sheep during winter and in lambs, and requires systematic prevention and early treatment to minimise suffering.
Key Conditions
Pasteurella pneumonia (Mannheimia haemolytica / Bibersteinia trehalosi): The most common cause of acute pneumonia in sheep. Can cause rapid death (peracute form) or acute illness. Primary welfare priority for vaccination.
Maedi Visna: Progressive viral pneumonia in adult sheep. Causes chronic weight loss, respiratory difficulty, and eventual death. No treatment; control through MV accreditation and closed flocks or tested purchases.
Ovine pulmonary adenocarcinoma (Jaagsiekte): Viral lung tumour causing progressive respiratory failure. Terminal; affected sheep should be euthanised promptly on welfare grounds.
Caseous lymphadenitis (CLA): Can cause internal abscessation affecting lung function. Contributes to chronic ill-thrift and welfare compromise.
Welfare Impacts
Sheep with respiratory disease experience: laboured breathing, depression, reduced appetite, fever, and pain. Unlike cattle, sheep rarely cough conspicuously; disease may be advanced before clinical signs are obvious to stockpersons. Regular, attentive observation is essential for early detection.
Prevention
Vaccination: annual pasteurella vaccination of the entire breeding flock; lamb vaccination from 3-4 weeks of age in enzootic pneumonia areas
Housing ventilation: adequate air changes without draughts, especially in housed sheep
MV testing and management: closed flocks, or testing purchases; MV-accredited status where achievable
Avoiding unnecessary stressors at housing
Treatment
Early antibiotic treatment of bacterial pneumonia under veterinary guidance significantly improves welfare outcomes. NSAID analgesia alongside antibiotics is best practice. Severely affected sheep with poor prognosis should be euthanised rather than prolonging suffering through treatment.