Farmer Denise Plummer advised dog owners to let their pets off the lead if they are approached by cows while walking in fields.

She was commenting following the death on Thursday of 68-year-old Sandra Wiltshire who was trampled by cows as she walked her elderly dog Bruce in fields near Riverside Drive, Chippenham. Bruce, also injured in the incident, was put down later that day.

Mrs Plummer, who has a dairy farm in Stanton St Quinton and is a former chairman of Wiltshire National Farmers’ Union, said: “I’m very saddened by it, it’s a tragic accident. I send out my sympathies to the lady’s family and friends.”

Mrs Plummer said walkers have to be particularly careful when they come across cows with calves.

She said: “As a mother they are protective. Some are worse than others. We do have the odd cow who when they have calved we know they will not be nice when we go and see to them.

“If you are walking with a dog and cows come over to you the best thing to do is to let go of the dog, it can usually run off to safety. Once you are knocked over it’s a problem.”

Mrs Plummer, a farmer for more than 50 years, said all animals can be unpredictable.

She said: “Thankfully this kind of incident isn’t common but it can happen. Having dealt with animals all my life - pets and farm animals - they are unpredictable. They can do things that are out of character. Things can happen, not necessarily animals charging at you. They can suddenly swing round and knock you over or be playful.

“Cows tend to follow each other, it’s the herd instinct. If someone is walking a dog and one or two cows start going towards them then it’s very likely the rest will follow. When you get a mass of them it gets quite dangerous.”

Mrs Plummer has a footpath and bridleway on her farm and said walkers sometimes stray off them.

She recalled an incident when a horse was spooked when she opened a gate causing the rider to fall off.