Thoracic Ultrasound Reveals Hidden Bovine Respiratory Disease in Healthy Calves
Thoracic ultrasound scanning can detect bovine respiratory disease in visibly healthy calves, according to new research from the Agri-Food and Biosciences Institute (AFBI). Published in September 2026, the study by researchers at AFBI Hillsborough and funded by Feed For Growth (Volac Milk Replacers Ltd) used portable ultrasound equipment to investigate subclinical pneumonia, which costs the UK cattle industry between £60 million and £80 million annually.
How Ultrasound Detects Subclinical Pneumonia in Calves
The trial tracked 108 calves receiving different dietary treatments until 13 weeks of age, recording daily feed intake and fortnightly live weights, according to AFBI. Researchers assessed the animals for visual signs of respiratory disease three times a week while performing lung scans at five to six weeks and 12 to 13 weeks. When scanned at five to six weeks, 5.6%—or six calves—showed moderate pneumonia, but only two exhibited visual symptoms. By the 12-to-13-week mark, moderate pneumonia cases rose to 14.8%, affecting 16 calves, none of which showed obvious clinical signs.
Did you know? Thoracic ultrasound scanning uses the exact same portable equipment that a veterinarian typically uses for cattle pregnancy scanning.
Expert Insights on Early Detection and Responsible Medicine
“The results of this study show that BRD can be present in visibly healthy calves, putting them at risk of reduced performance and efficiency throughout their lifetime,” according to AFBI researcher Dr. Gillian Scoley. Dr. Scoley noted that thoracic ultrasound scanning identifies subclinical disease to improve early detection rates, allowing farmers to treat individual animals based on actual severity rather than applying blanket treatments across groups.
Dr. Jessica Cooke from Feed For Growth explained that the trial examined whether different nutritional planes affected lung health, noting that nutrition influences immune function and disease resilience. Iain Smith from Lisburn Veterinary Clinic, who performed the scans for the study, added that lung scanning helps detect hidden lung damage, evaluate vaccination program protection, and guide treatment decisions.
Recognizing Early Signs of Bovine Respiratory Disease
AFBI advises producers to monitor herds closely during high-risk periods—such as weaning, mixing, or disbudding—when stress and environmental factors like low temperatures, high humidity, and poor ventilation worsen bacterial or viral infections. Calves lacking adequate colostrum at birth also face heightened risk. Common clinical signs to watch for include:
- Reduction in milk intake
- Flicking or drooping of the ears
- Discharge from the eye or nose
- Coughing
- High temperature exceeding 39.5°C
- Listless or dull behavior
- Lifting or blowing
Frequently Asked Questions
What causes bovine respiratory disease in calves?
BRD is caused by bacteria or viruses and is exacerbated by environmental factors like poor ventilation, high humidity, low temperatures, and stressful events such as weaning or disbudding, according to AFBI research.
Can a calf have pneumonia without showing symptoms?
Yes. AFBI research found that a significant number of calves with moderate pneumonia showed no obvious visual signs of respiratory illness.
How does thoracic ultrasound help manage BRD?
Thoracic ultrasound allows vets and farmers to detect hidden lung damage and treat individual animals based on actual disease severity rather than using blanket treatments, supporting the responsible use of medicines.
What strategies is your farm using to monitor respiratory health in young livestock? Share your thoughts or questions in the comments below.
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