IRRESPONSIBLE horse riders in the New Forest are ruining an attempt to contain any outbreak of foot-and-mouth disease.

Riders trekking across the countryside are leaving gates open, allowing cattle to wander from one part of the Forest to another.

Earlier this year the area was divided into six separate zones by the Forestry Commission.

The scheme aims to prevent a mass slaughter of cloven-hooved stock across the Forest if any animal shows symptoms of foot-and-mouth.

Any cull would be restricted to the zone in which the infected animal was grazing.

But the New Forest Liaison Group says riders are undermining the scheme by leaving gates open when they move from one zone to the next.

Dave Atwill, the group's spokesman, said: "Much of the Forest is now open to walkers, cyclists and riders, but the situation is being carefully monitored.

"Several gates were left open at the weekend, allowing cattle to wander through. Riders were seen going through the gates and not shutting them.

"If the worst did happen we would never contain the outbreak if cattle could wander freely between the zones.

"I would ask everyone who uses the Forest to do so responsibly."