Thirty patients and three members of staff are believed to have contracted the norovirus.
Hospital managers are now urging people to take all the usual measures to stop the problem from getting worse.
Infection Control Manager Elaine Ross explains more:
More top news
Our experts take a look at the key issues that would face Scotland and the rest of the UK if Scots vote for independence.
A look ahead at the forecast for the Border region.
Thousands of people cross the border to visit their doctor. Patients on both sides are worried about the possible effects of a “yes” vote.