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
Mainly dry until later on Wednesday. A cooler, showery and blustery end to May
Mainly dry. Light rain out of thicker cloud over hills. Breezy at times and cooler than average
A look ahead at the forecast for the Border region.