Galway had the highest number of herds locked up with TB, while Dublin had the lowest with just 21 in 2017, according to the latest figures from the Central Statistics Office (CSO).
However, the number of cattle tested in both counties differed hugely with 396,072 animals tested in Galway and just 21,356 animals tested in Dublin.
Overall since 2013, the number of herds undergoing testing has dropped, while the number of animals has increased.
This has been particularly evident in counties with a traditional dairy base, such as north Cork which had the highest number of animals tested and saw an increase of 40,917 more animals tested in the last five years.
But this expansion has come at a cost, with the number of herds locked up in north Cork increasing to 270 in 2017, and the rate of TB herd incidence going up to 4.72%.
Counties with highest number of herds locked up:
TB blackspot areas also featured in the latest statistics, with 61 herds locked up with TB in west Wicklow.
While the figure may seem low compared to other counties, the figure accounted for over 10% of their herd, with the area consecutively having the third highest annual herd incidence rate in Ireland.
The average per thousand rate of cattle in Kerry with TB jumped from 1.65 at the end of 2015 to 2.62 in 2017.
The Iveragh Peninsula was particularly hard hit last year, with 366 reactors removed and 75 herds were restricted.
Minister for Agriculture Michael Creed, has announced that there will be a review of the current TB eradication.