Overbreeding means horses are cheap to buy, but they remain expensive to keep. This has led to a spike in cases of them being discarded, according to the RSPCA

The imaginative gulf is jaw-dropping. It starts with a kitsch tween dream of horse ownership – or ideas of cashing in on the breeders’ market. It ends with a horse dumped on a garbage heap.

The RSPCA has noticed a big uptick in “horse fly-tipping”, so much so that it is talking of a “horse crisis”. Prosecutions involving horses are up 25% since 2015. The society rescued 1,000 horses last year.

Horses are expensive to keep. Besides the feed, there are the vet bills. A case of colic can cost £5,000 to fix. Even in death they are pricey: a horse cremation can cost £500. Increasingly, owners unwilling to shoulder the costs simply abandon their animals.

Individual cases can be horrifying. In Dartford, Kent, the body of a horse was found under a pile of planks, next to a can of petrol. Six dying horses were later found on the same site. In Orsett, Essex, a mare was dumped by the side of a road while she was in labour. Mother and foal later died. In Upminster, east London, a horse with a swollen leg was found tied up at a fly-tipping spot. It had to be put down. The RSPCA notes that the biggest spike always comes during winter, when grazing is scarce and redworm becomes an issue.

Why the crisis? The problem has push and pull factors. Overbreeding issues have been brewing for years. With the market saturated, horses are changing hands for as little as £25, or even for free. They are picked up by naive owners who don’t understand that the upkeep is the true price of ownership. “When you look at insurance, stabling costs and microchipping, it’s probably in the hundreds per month,” says the RSPCA’s national equine co-ordinator, Christine McNeil. When injury or illness take hold, the horses are discarded.

Hay prices are rising, too. The solution of some owners has been equally antisocial: fly-grazing – pasturing your horse on land you don’t own. This became so widespread that the government introduced the Control of Horses Act 2015 to punish offenders.

The RSPCA is trying to get to grips with the overbreeding problem, but it is a long slog. “There’s no typical horse dumper,” McNeil says. “But we think it’s the breeders that are at the root of the problem, where they began with the intention of making a profit and now it’s costing them to keep horses that are worthless on the open market.”