Lung Ultrasound Scanning for BRD in Calves
Bovine Respiratory Disease (BRD) continues to be one of the most costly and welfare impacting conditions in youngstock. For years, our diagnostic tools have relied heavily on clinical signs such as coughing, nasal and ocular discharge, fever, or altered breathing patterns. But research and experience on farms shows that these outward signs are poor predictors of true lung pathology. On nearly every farm there will be animals with pneumonia showing no clinical signs at all, carrying potentially significant lung damage that affects growth, feed efficiency, and future performance. It is suggested that for every clinical case of pneumonia, there are 3 subclinical cases showing no clinical signs.
This is where thoracic ultrasound, or lung scanning, has become a game changer.
Why Calves Need Lung Scanning?
- 1. Sub-clinical pneumonia is common – and costly – Recent work shows a high proportion of calves have lung consolidation without showing outward signs of disease. These subclinical cases often go unnoticed, however, on average:
- They grow more slowly
- Convert feed less efficiently
- Have an increased risk of clinical BRD later
- Are more likely to require treatment later in life
- Are at a higher risk of being chronic poor performers
2. Clinical signs alone are unreliable
- Traditional BRD detection tools – temperature, coughing, nasal and ocular discharge, breathing rate – have low sensitivity and specificity. This means we miss real cases and incorrectly treat healthy animals with these methods.
- In contrast, thoracic ultrasound consistently shows a much higher sensitivity and specificity, making it more accurate than any clinical scoring system, stethoscope, or technology currently available.
3. Lung Scanning is fast, practical, and affordable
- Using a simpler linear probe (the same one we use for PD scanning!), a quick thoracic ultrasound takes around 1-2 minutes per calf, requiring no clipping and needs only alcohol as a contact agent.
What Lung Scanning Can Tell Us
Allows us to visualise –
- Normal lung
- Lung consolidation
- Severity of pneumonia (by depth of lesion)
- Other conditions – abscess/pleuritis
And many other things in-between!
The key benefit is that we can detect exactly which calves have pneumonia and treat accordingly – which is crucial for targeted antimicrobial use.
Why this matters for antibiotic stewardship?
One of the biggest challenges in responsible antimicrobial use is knowing which calves genuinely need treatment. With only clinical signs, we tend to over-treat to avoid missing cases.
But ultrasound changes the equation:
- Treat only calves that show evidence of pneumonia
- Avoid unnecessary antimicrobials in calves with upper respiratory signs
- Reduce overall usage whilst improving outcomes
Farms using lung scanning routinely often report:
- Fewer antimicrobial treatments
- Better calf growth curves
- Lower mortality
- More predictable batches at weaning
A More Informed Approach to Calf Health
Routine lung scanning can be implemented on farm:
- At arrival for purchased calves
- At strategic points during milk feeding period
- When clinical respiratory disease is suspected
- For follow-up treatment to assess recovery
The results allow us to adjust:
- Early life and colostrum management
- Ventilation and housing
- Nutrition strategies
- Vaccination programs
- Antimicrobial policies
The Bottom Line: Better Data, Better Decisions
Lung scanning gives us objective, real-time information about what is happening inside the chest of each calf. By revealing the invisible burden of subclinical pneumonia, thoracic ultrasound allows farmers and vets to make smarter, more targeted, and more cost-effective decisions together.
It is not just a diagnostic tool, it is becoming an integral part of modern calf health management.
If you would like to explore lung scanning on your farm, or discuss how this could fit into your system, please get in touch with either myself or one of the other vets!
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