"By that I mean try to imagine creating a cavity inside your mouth without any air bubbles and by letting in no air through your lips or throat -- it's basically impossible at sea level because the air pressure outside your mouth pushes the air pocket closed, " he said.
The total number of foot-and-mouth outbreaks in the Borders has been well below the level in neighbouring Dumfries and Galloway, which experienced the majority the country's cases.