Cattle and sheep will be in the 550 hectare grazing area of the Ashdown Forest between the A22 and the B2026 from April 1 until further notice, Conservators say.
People can walk where they like during the grazing season but if they go through a gate they are asked to make sure it is closed behind them. And they are also advised to make sure dogs are kept under close control at all times, preferably on a lead.
Experts say even the most friendly and placid of dogs can become killers once instinct takes over and the chase is on.
Dogs can kill sheep or inflict appalling injuries on them. Even if it does not catch or bite, the stress of being chased can make pregnant ewes abort their lambs.
And farmers can legally shoot dogs worrying livestock. Where cattle are concerned, the NFU explains cows may see a dog as a threat and act defensively, especially if they have calves to protect.
Try not to get between cows and their calves, be prepared for cattle to react to you if you have a dog with you, move quickly and quietly and walk round the herd. If threatened, let go of your dog’s lead as the cattle will chase the dog.