Extra bio-security measures are being brought in for cattle on Epsom Common after the latest outbreak of foot-and-mouth disease in Surrey.
Straw and disinfectant has been placed at some access points to grazing areas, and other access points are closed.
Epsom council said the low-key measures were consistent with Defra advice to farmers outside the surveillance zone.
The cattle are already checked twice a day but a vet is now also being brought in to carry out extra inspections.
Cattle were put on the common in 1997 by the council so their grazing would keep areas of scrub down and encourage rarer plants to flourish, such as common spotted and southern marsh orchids.
'Plea for co-operation'
The spokesman added that the cattle were usually taken to a grazing farm in winter and this would now happen when movement restrictions were lifted.
Notices have been placed around the grazing area to inform residents of the actions being taken.
The spokesman said the council was asking for people's "cooperation in respecting the precautions" and also wanted them to "apply common sense in their own movements around animals".
There are 20 cows in the herd on Epsom Common nature reserve including cross-breeds and two pure Friesians.
A local farmer lends the cows to the council so they can graze on the common during the summer.
The council said grazing was a sensitive way of maintaining the grassland without disturbing other wildlife, and cows' hooves trampled bracken and other undesirable plants.
Epsom council put grazing cattle on the common to control scrub
The herd has now been caught up in the latest outbreak of foot-and-mouth in Egham - about 20 miles away.
A case of the disease was discovered last Wednesday in cattle on grazing land attached to Milton Park Farm, in a herd belonging to Robert Lawrence.
It was later confirmed on a second site nearby - Stroude Farm, owned by Ernest Ward.
A 3km (1.8-mile) protection zone has been set up around the farmland, with a 10km (6.2-mile) surveillance zone encircling it.
Laboratory results have established the virus found at the latest outbreak to be the same strain as the one in Pirbright in August.
On Saturday, four cattle escaped from a field at Ripley as vets and slaughtermen arrived to carry out a cull.
Country fair cancelled
Defra said a small number of animals entered an adjoining field but officials including police responded quickly and the situation was under control at all times.
A spokesman said: "There was no biosecurity breach and no threat to humans or other animals."
A ploughing match and country fair that was to be held on 23 September at Loseley Park has been cancelled because of the outbreak, Surrey County Agricultural Society has said.
"It was a difficult decision but Loseley Park estate now falls within the foot-and-mouth surveillance zone," a spokesman explained.
He said most events for Surrey Farm and Village Week, which started on Saturday, have also been cancelled to protect livestock farms.
A list of events still taking place can be found on the county show website.