Scotland officially achieved tuberculosis-free (OTF) status in September 2009, thanks to a relatively low and stable incidence of the disease in cattle herds.

But this doesn’t mean there are no cases of bovine TB in the country.

In fact, between 10 and 17 herds per year have experienced a TB breakdown since 2010.

However, where less than 0.1% of herds experience the infection annually, a country or region is able to remain OTF.

Most Scottish TB cases can be traced back to a single consignment of cattle from across the border in England.

Reasons for low status

Scotland has managed to maintain its TB-free status thanks partly to having a lower density of cattle in the country.

The island of Ireland and Scotland may be of similar size, but Scotland has far fewer cows than Ireland, with only 420,000 suckler cows and 160,000 dairy cows.

There have also been only five known TB cases in the wildlife in Scotland – four deer and one badger

Furthermore, Scottish farms are typically bigger, self-contained and more spaced out than in other parts of Britain or Ireland.

There have also been only five known TB cases in the wildlife in Scotland – four deer and one badger. The most recent case was a red deer shot in 2003. However, there is no routine testing of wildlife and little political appetite to investigate further. Experts from the University of Exeter put the badger density in Scotland at half of that of England.

Breakdown rules

If a farm has a confirmed case of TB, then the farm tests at least every 60 days until no more reactors or inconclusive results are detected. Any animals which fail the test must be isolated and then destroyed.

Neighbouring herds with nose-to-nose contact are also tested

One or two clear tests will need to be conducted, followed by another test six to 12 months later, before full TB-free status is awarded again to the herd.

Neighbouring herds with nose-to-nose contact are also tested.

Movement testing

Any animals which are brought on to a Scottish farm from other parts of the UK must complete pre- and post-movement testing.

Cattle coming directly for slaughter, to a show or exhibition, or under six weeks of age are exempt from these requirements.

Cattle moving from four-yearly testing areas of England and Wales are exempt from the pre-movement test but not the post-movement test.

Luck has a lot to do with obtaining our TB status

Cattle from the Republic of Ireland also need pre- and post-movement testing, but if a reactor is found then no compensation is paid, unlike cattle moving within the UK.

Compensation is capped at £7,500 for all purebred pedigree cattle and £5,000 for non-pedigree cattle.

NFU Scotland’s Penny Middleton, who handles the organisation’s TB policy, said: “Luck has a lot to do with obtaining our TB status as we have avoided importing large amounts of the disease over the years. But the main difference is we don’t have a TB reservoir in our wildlife population.

Our status helps regarding trade terms and also gives us freedom on how to do our own testing and management

“We know this because we do not have farms getting re-infected with TB after an outbreak has been dealt with. Our biggest risk to TB breakdowns is through imported animals from high-risk areas.

“Our status helps regarding trade terms and also gives us freedom on how to do our own testing and management. If we lost our status, we would have a lot more testing on the farm as many are currently exempt.”

Scotland’s TB regime

To maintain OTF status, farmers need to take part in a testing regime through on-farm testing and through abattoirs.

Farms have to test their herd every 48 months unless they have an exemption. Many farmers can take advantage of the exemption as they are identified as “low risk”. Low-risk herds must comply with one of the following criteria:

  • Fewer than 50 cattle on the farm with no more than one consignment of cattle from a high-incidence TB area in the last four years.
  • The herd slaughters more than 25% of their stock annually in each of the previous four years and not more than one consignment of cattle moved from a high-incidence TB area in the last four years.
  • Herds that slaughter more than 40% of their stock annually for each of the last four years.
  • All carcases are inspected by Food Standards Scotland for evidence of TB lesions. If any are found, the farm is locked down and further investigations are conducted.