Pneumonia is one of the most significant welfare challenges in sheep farming globally, causing acute respiratory distress, chronic debilitation, and death across all sheep-producing regions.
Pneumonia causes acute respiratory distress that represents one of the most recognisable and severe welfare states in sheep. Affected lambs and adults breathe rapidly and shallowly, may extend their necks to maximise airflow, and show the visible signs of physiological distress — hunched posture, sunken eyes, and separation from the group. Chronic forms, including maedi-visna in adults, cause progressive weight loss and exercise intolerance over months or years. The social nature of sheep means that an individual in respiratory distress is simultaneously suffering and excluded from normal group behaviour, compounding welfare harm. Early detection through daily flock observation — identifying individuals that are separate from the group, breathing rapidly, or reluctant to move — allows prompt antibiotic treatment when bacterial infection is the cause. Vaccination and improved housing ventilation are the most important preventive welfare investments available to sheep farmers.