Since lockdown restrictions eased and travel for exercise became permitted, large numbers of people are heading to countryside sites across East Sussex.
With animals grazing on land on many countryside sites, the county council is calling on walkers to keep their dogs on leads and under control around livestock.
Cllr Claire Dowling, the authority’s lead member for transport and environment, said: “We appreciate people are keen to get out and about and enjoy the countryside but there is absolutely no excuse for attacks on livestock.
“There are working farms across East Sussex’s countryside sites and these attacks have a devastating effect on farmers and their livelihood.”
Under the Dogs Act 1953, it is a criminal offence to let a dog worry sheep and the owner of the dog could be liable for a fine of up to £1,000.
Cllr Dowling added: “In current circumstances, any visitor to the countryside has a duty of care to ensure they can socially distance to help prevent a second wave of Covid-19.
“But dog owners also have a responsibility to keep their pets under control at all times to prevent them from attacking livestock. One way to do this is to ensure they are always kept on a lead when crossing fields where livestock is grazing.”
Anyone who witnesses a dog on the loose worrying sheep, should report it to Sussex Police by calling 101.