16% of deer in Wicklow carry TB

16% of deer tested in Co Wicklow were found to be carrying tuberculosis (TB), a pilot study has revealed.

The study, carried out by the Department of Agriculture, saw 103 deer in Wicklow shot by a licensed deer hunter and the carcases analysed. Of the 103 carcasses analysed, it was found that 87 did not carry TB, while 16 had “evidence of M. bovis”. M. bovis is a slow-growing, aerobic bacterium and the causative agent of tuberculosis in cattle.

It has long been suspected that deer transmit TB to cattle. However, this is the first study to directly link the two.

Wicklow has developed into a hotspot for TB in cattle. In 2014, the herd incidence of TB in east Wicklow was 8.15%, while it was 8.47% in west Wicklow.

A total of 4,111 beef herds were affected by TB in Ireland in 2014 – 3.64% of the total number of herds in the country. Reacting to the report, Wicklow IFA chairman Tom Short said farmers in the county now have concrete evidence that deer are passing TB on to cattle.

He said: “Farmers have had real concerns in relation to the role wild deer encroaching onto their land is having in prolonging TB episodes and contributing to new outbreaks. This study confirms both the incidence of TB in deer and the risk they are posing to the health status of the cattle in the farms they are encroaching upon.

“It is more than coincidental that Wicklow has both the highest levels of TB in cattle in the country and the highest population of deer. This situation must be addressed urgently by all state agencies responsible, through a targeted reduction in deer numbers surrounding TB outbreaks and a national management plan that reduces deer numbers to what is sustainable within their natural habitat in order to protect the health and welfare of our animals and farmers’ livelihoods,” Short added.

IFA president Eddie Downey welcomed the publication of the report and called for action to address the TB problem in Wicklow.

“Farmers have long argued that the control of the deer population is an important element in the eradication of the TB disease. The evidence from this study shows the level of TB in deer is a significantly higher multiple than in cattle and justifies the implementation of a programme similar to the existing wildlife control programme,” Downey said.