Pádraig O'Sullivan (Cork North-Central, Fianna Fail)
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165. To ask the Minister for Agriculture, Food and the Marine the number of bovine tuberculosis outbreaks nationally in 2023, 2024 and to date in 2025; the number of false positives recorded during the same period; the steps he is taking to improve the testing regime, in tabular form; and if he will make a statement on the matter. [25341/25]

Martin Heydon (Kildare South, Fine Gael)
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Bovine TB is a challenging disease to control and eradicate. In recent years, bTB levels have continued to deteriorate, herd incidence has increased from 4.94% in 2023 to 6.04% in 2024. As of 11th May 2025, over a 12-month period we had a herd incidence of 6.30% with over 42,200 reactors. This disease is having an impact on our farmers and their families emotionally and financially throughout rural Ireland.

The table below sets out the number of TB breakdowns in 2023, 2024 and to date in 2025.

When cattle are slaughtered as reactors under the TB Eradication Programme, it is because they have tested positive for infection with TB. The tests used for TB in cattle are known to be highly specific. For example, the standard skin test used as the basis of our programme is estimated to have a specificity of 99.98%.

This means that one in five thousand truly negative animals tested will react positively to the test.

It is not routine to perform culture or other laboratory tests on all TB reactors, and such tests are generally less sensitive than the skin test and other ante-mortem tests. So, while it is not feasible to determine precisely the number of false positives removed under the TB programme, we can be confident from the available scientific knowledge that such false positives will represent a small minority of total reactors.

Visual inspection of reactor carcases at post-mortem finds that, on average, in the years from 2014 to 2024 a range of 23-39% of such reactors had visible lesions of tuberculosis, meaning the infection has progressed to a stage where the disease process has caused such significant tissue damage that it can be seen with the naked eye.

The table below shows Lesion % rate 2014 – 2024. Generally lower lesion rates indicate a higher proportion of new infections relative to older infections and earlier detection of positive animals overall.

If a reactor does not have visible disease lesions, it does not mean it is not infected; visual inspection cannot detect the presence of microscopic lesions and bacteria within the tissues of such animals. Most TB reactors have “no visible lesion” (NVL) when the routine postmortem examination is carried out by veterinary staff at slaughterplants.

The majority of such NVL animals are in fact infected with TB- they have just been detected sufficiently early that lesions have not become apparent to the naked eye.

Number of Herds in TB Breakdown

Table of Lesions % rate 2014-2024