Well-meaning members of the public are being warned not to feed horses while out on walks — as it can lead to harm.

The British Horse Society (BHS) said it had been made aware of instances where horses have been seriously injured, made extremely ill or in some cases even dying due to the public feeding horses.

Preliminary research led by the University of Bristol showed that more than three quarters of horse owners surveyed found that their horses were fed without their permission, and 83% of those responsible were families — with instances occurring more frequently during lockdown.

The BHS — which launched a #BeHorseAware campaign in April 2020 highlighting the dangers — said horse owners had encountered other problems too such as members of the public leaving gates open.

The survey of 1,017 people in 2020 also found that nearly a third of horses became unwell as a result of being fed without permission, with half of these needing veterinary treatment.

Almost a third of those that required treatment did not make a full recovery and shockingly 16% died or were euthanised.

The BHS is also advising got owners to keep their pets on a lead as they may startle horses, which can cause injury.

People who see a horse in distress are asked to alert the nearest farm or check for a sign with the owner’s detail on.

The BHS has produced free signs for horse owners to place around their fields warning the public not to feed their horses which are available at bhs.org.uk/behorseaware.

Janet Holmes, BHS regional manager for the East of England, said: “The BHS is urging members of the public in East Anglia to take notice of our #BeHorseAware campaign and not feed horses in fields as this can cause serious, potentially life-threatening illness.

“We believe many people act with no malicious intent and at this time of year members of the public think that they are helping a hungry horse.

“However, they are unaware of the timings at which owners feed their horses and the risks that certain foods or grass cuttings can pose.

“If members of the public feel that a horse is being mistreated or underfed, we would ask them to contact the BHS welfare helpline for advice.

"We also encourage horse owners to download free signs the BHS has produced warning the public not to feed their horse. The greater the awareness of the issue, the more likely people are to change their behaviour in the future.”

Dr Jo Hockenhull, senior research associate at the University of Bristol Vet School, said: “It is important to recognise that in many of the cases reported in our survey, horses and ponies are being fed household vegetables and items that you would think are safe like grass, apples and carrots. Even if you think it is harmless, the horses might have underlying health issues or allergies.

“Our research shows that the consequences of feeding horses anything without permission can be very serious or even fatal.”