Ovine Respiratory Disease: Welfare, Diagnosis, and Control

Respiratory disease is a leading cause of sheep welfare problems and economic losses globally. Pneumonia in sheep—whether enzootic (chronic) or acute—causes significant suffering and, when untreated, prolonged pain and death. Effective prevention and rapid treatment are essential welfare priorities.

Forms of Ovine Respiratory Disease

Enzootic pneumonia: Caused primarily by Mycoplasma ovipneumoniae and secondary bacterial pathogens, this chronic form causes poor growth, respiratory distress, and mortality, particularly in young lambs. Pasteurellosis: Acute pneumonia caused by Mannheimia haemolytica and related bacteria, often triggered by stress events (weaning, transport, housing). Can kill rapidly and causes severe suffering. Ovine pulmonary adenocarcinoma (OPA): A retrovirus-caused lung tumor with no treatment—welfare management focuses on early culling decisions.

Welfare Indicators

Welfare-conscious stockpeople look for: increased respiratory rate, nasal discharge, coughing, labored breathing, depression, reduced feed intake, and weight loss. Early identification enables prompt treatment and reduces suffering duration.

Prevention Strategies

Prevention is the welfare priority: vaccination against pasteurellosis, colostrum management for passive immunity, good ventilation in housed sheep, biosecurity to prevent pathogen introduction, and minimizing stress events. Closed flocks have lower respiratory disease prevalence.

Treatment and Welfare

Prompt antibiotic treatment when clinically indicated reduces suffering significantly. NSAIDs (anti-inflammatories) provide important pain relief and improve outcomes. Delay in treatment is a welfare failure—affected animals should be treated same-day where possible.

Resources


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