Understanding the Impact of Bovine TB on Cattle Herds: How historic test data can help prevent future infection

Article written by John Walsh, BVSc MRCVS DBR

Bovine tuberculosis (TB) remains one of the most significant disease challenges facing our clients. Its effects extend far beyond the immediate disruption of a breakdown and can influence herd performance, business resilience, and long‑term productivity. At Friars Moor Livestock Health, we are working not only to support you during breakdowns but also to help prevent infections in the future. We can carry out TB advisory visits for farms after a TB breakdown.

Bovine TB (bTB) was almost eradicated in the 1970s, largely due to the skin test that was first used by vets in the 1940s and still underpins the government control strategy for bTB today.

The fact that we are still battling to eradicate bTB in 2026 has seen the skin test come under quite a lot of criticism. It is easy to forget that when skin testing first took place, livestock keepers and vets were seeing clinical cases of TB in cattle.

Diagnosis was difficult and animals would typically become chronically unwell, unproductive and lose weight. It is important not to forget how far we have come since the introduction of skin testing.

As a result of surveillance we are unlikely to ever see a case of clinical TB. What we do know is that the skin test is highly specific and as a result, false positives are unlikely. However, this comes at the expense of sensitivity which can lead to large numbers of infected cattle slipping through the net. We also know that more needs to be done in order to identify ‘High Risk’ cattle which are likely to be a source of residual infection, as well as targeted improvements in biosecurity to prevent reintroduction of disease.

A TBAS visit entails a free visit where we will:

• Initial Discussion: Paul Doran our trained TBAS advisor discusses your farm setup, current TB concerns, and any history of breakdowns.
• Farm Walk-Around: The advisor and farmer survey the farm to identify risks related to cattle, badgers, slurry, and feed/water sources.
• Risk Assessment: The visit focuses on practical biosecurity, such as securing feed stores, elevating water troughs to prevent badger access, and managing livestock, slurry, and herd movements.
• Action Plan: At the end of the visit, you and the advisor agree on four tailored, cost-effective recommendations to implement.
• Follow-Up Visit: A second, free, follow-up visit occurs 3-6 months later to assess the implementation of the recommendations.

As well as offering TBAS visits we have developed our own ‘TB dashboard’ to Identify At Risk Animals

TB and Johnes disease are caused by very similar bacteria and have similar disease patterns. We have developed a tool to identify at risk animals based on historic skin test results, like the Johnes results you get from your milk recording organisation.

We use the tool to review historic skin test results for every animal in the herd, look for patterns of inconclusive results and those previous readings that were close to threshold. Using this proactive approach we can produce lists of high-risk animals for you.

This may highlight high risk groups or ages that you can then manage to reduce the risk of future breakdowns in your herds.

Our Commitment to Proactive TB Prevention

TB control isn’t just about responding to breakdowns—it’s about staying ahead of them. At Friars Moor Livestock Health, we are committed to using data, technology, and herd‑specific insights to help you protect your livestock and your business.

If you’d like your own TB Dashboard Report or want to discuss what your herd’s historic data shows, please contact the practice. Our team is always ready to help you take the next step in TB prevention.