The Blue Cross will be fighting equine obesity by selling its Fat Horse Slim weight management packs on its stand at Blenheim Horse Trials this weekend.

The campaign, launched earlier this year, has attracted the support of several leading riders, including Mary King and William Fox-Pitt.

Obesity is an increasing problem among British equines, with 40 per cent of admissions to the Blue Cross’s equine centres last year being overweight.

Rosie Mogford, equine welfare education officer for the Blue Cross, emphasised the importance of managing horses’ weight in the winter, as well as over the summer.

“Wild horses naturally lose weight in the winter but domesticated horses can do the opposite, often through the overuse of rugs, stabling and hard feed,” she said.

The campaign also highlights the need for special care of older or less hardy horses, such as thoroughbreds, over the winter.

Although they may require extra rugging, stabling and feed, they must not be allowed to become too fat.

Katie Williams from feed manufacturer Dengie, which is sponsoring the Blue Cross campaign, added: “Feeding plenty of fibre in the winter is important not only for maintaining normal gut functions but also for keeping the horse warm.

“In addition to fibre, vitamins and minerals are required to keep your horse or pony healthy.”

The packs include weight management tools, such as a weight tape and weight change wall chart and will be available from the Blue Cross stand 54 at Blenheim Horse Trials.

They will be priced at a discounted £5 (usually £8).