Vegetarians International Voice for Animals, the UK organisation that promotes a vegetable-based diet, has launched an insert campaign to put a stop to the live transportation of horses for food.
The "Journey to Death" leaflet aims to raise funds to stop horses being transported to Italy from Poland for slaughter.
The charity, which has ploughed £25,000 into the campaign, hopes the appeal will break even.
About 410,000 leaflets have been inserted in 13 publications including BBC Wildlife, The Observer, Your Horse, Horse & Rider and Healthy You.
The A3 insert has been folded to A5 size and uses the image of a foal with the strapline "A wonder of nature or Sunday roast?" The leaflet unfolds to reveal a horse injured in transportation.
The campaign asks for cash donations of between £10 and £250. The organisation is also looking to secure standing orders of either £3, £5 or £10 a month from at least 100 regular givers.
The money raised will enable its Polish operation to lobby the country's government and rally support from the public, who cannot be entered onto a database because of strict legislation.