IN 1931, a member of the Melrose gentry, Dorothy E. Brooke, now living in Cairo, was horrified to see hundreds of emaciated war-horses stumbling around the city, desperately in need of food and medical attention.

The horses had been brought out to the region by British forces fighting in Egypt, Palestine and Mesopotamia.

"Those sold at the end of the war have sunk to a very low rate of value indeed: they are past 'good work' and the majority of them drag out wretched days of toil in the ownership of masters too poor to feed them – too inured to hardship themselves to appreciate, in the faintest degree, the sufferings of animals in their hands," Brooke wrote in a subsequent letter to an English daily newspaper. Many of the horses were blind, and all were skeletons, she added.

Her letter aroused such sympathy that readers sent her the equivalent of £20,000 in today's money so that she could help the horses. Over the next three years she bought 5,000 of them. Most had to be put down, but at least they ended their lives humanely.

In 1934 Brooke established the Old War Horse Memorial Hospital in Cairo, promising free veterinary care for all the city’s working horses and donkeys. The Brooke Hospital for Animals was born.

The charity lives on today, as Brooke Action for Working Horses and Donkeys, at a time when an estimated 100 million horses, mules and donkeys are working in punishing conditions in some of the poorest countries in the world.

Brooke had arrived in Egypt in 1930 with her second husband, Major General Geoffrey Brooke, who had received the Distinguished Service Order in the war and went to Cairo to lead the British Cavalry Brigade.

During the Great War, across all the fields of conflict, no fewer than eight million horses, donkeys and mules died. Of the one million sent out from the United Kingdom, only 60,000 returned home.

"Some horses, because there was no resolve to bring them home after the war, were sold in markets, some of which were in Cairo," says Jamie Whear, media and content manager at the London-based charity. "Those were the horses that Dorothy Brooke went out to try to find in the early 1930s. She found them, too.

"My understanding was that she was part of the aristocracy [in Melrose] and came from a long line of horse-loving families. There was a circle of ladies who were very determined to take action after the war, to find these animals. And of course they had the money to get out there.

"Dorothy continued working for the charity up until her death in June 1955, in Cairo."

Brooke's letter to the Morning Post in 1931 struck a chord with countless readers.

It ended with these words: "If those who truly love horses – who realise what it can mean to be very old, very hungry and thirsty, and very tired, in a country where hard, ceaseless work has to be done in great heat – will send contributions to help in giving a merciful end to our poor old war heroes, we shall be extremely grateful; and we venture to think that, in many ways, this may be as fitting (though unspectacular) part of a War Memorial as any other that could be devised."

* Brooke's year-long campaign, Every Horse Remembered, seeks to raise £1 million to honour the millions of animals lost, and save millions now and in the future. A commemorative pin-badge is available from thebrookeshop.org, tel. 020 7470 9393