The slain dogs are a violent by-product of rural Spain's fascination with hare coursing, a sport in which owners often regard their animals as disposable.

Tens of thousands of greyhounds run hare coursing races in rural Spain each year. At the end of the season many are hanged - slung from trees with a piece of twine - and if their owners think they have run badly they sometimes hang them with their back paws on the ground for a slower death.

Fermin Perez, head of a dog sanctuary at Medina del Campo in central Spain, says he has been told of these methods by racing dog owners. The British-based World Society for the Protection of Animals (WSPA) also describes them in a report.

"I've seen dogs hanged at every angle you can imagine," Perez told Reuters.

Owners have invented grim terms to describe the different execution methods. Hanging dogs with their back feet on the ground is called "the secretary" or "the piano player", referring to the scrabbling of the dog's front legs as it tries to reach the ground, according to WSPA and locals in Medina.

"If they're not running, they hang," said Angel, a 21-year-old former hare courser from Medina del Campo.

"Greyhounds are for racing. What else are you going to do with one? You wouldn't exactly take it for walks around the plaza," he said with a giggle. "For stupid people, it gives them a kick," he said, referring to hanging, adding that some owners also shot or abandoned their dogs.

The WSPA said in a recent report: "Hanging is an age-old tradition and the most popular method of 'disposing' of these dogs." Other methods include stoning and staking dogs in a pond to drown.

STARVED, NOSES DOCKED

The WSPA also says the greyhounds - slightly different from Italian greyhounds and known in Spain as "galgos" - are typically treated badly during their short life - fed on bread and sugar and neither vaccinated nor wormed.

A greyhound arrived at the end of January at Perez's shelter with a deformed nose. Perez said the former owner had explained that in his village owners always chopped off the end of their dogs' noses to make them run faster.

Traditionally, according to the WSPA, greyhounds were used by poor people for hunting meat. Owners could not afford to keep the dogs once they had outlived their usefulness and so they killed them in the cheapest possible way.

Now the greyhounds - docile and trusting - race, and the WSPA estimates that 50 percent of dogs die by the age of two, with owners reluctant to pay for their upkeep after they have run one season. They run their first season at 12 months.

A Medina-based veterinary surgeon said putting down a dog cost around 30 euros ($32) - a price aficionados are unwilling to pay.

"There'll be more than one out there," said a local man when told of the dog hanging in the wood. "It tends to happen, when the season ends, dead greyhounds start turning up."

Remains of hanged dogs which have been later burned have also been spotted by the WSPA.

The season lasts from October 1 to January 31 and races are held from dawn until dusk two days a week in the Medina area. The first dog to grab the hare usually wins and prestige is the reward for the owner rather than prize money or gambling winnings, locals say.

OLD LAW, NEW LAW

A local law was passed in 1997 in Old Castile and Leon setting a 15,000 euro fine for dog-hanging but it has never been enforced, according to a local government official.

"The police receive reports that the animals are there... but they never find those guilty so there can't be a prosecution," the official said, adding that prevention was impossible and no extra measures were being taken to put an end to the tradition.

Spain - famous for bull-fighting - made cruelty to animals a crime earlier this year but the question remains as to whether the new law will be enforced any more than the local one.

The Castile-La Mancha Greyhound Federation says it opposes hanging and that the practice is on the decline.

Medina del Campo, a medieval town on the Castilian plains, is the centre of Spanish galgo racing.

Signs of the craze - which Perez says has become even more popular over the last decade - can be seen in photography shop windows and on car bumpers.

The town boasts a sculpture of two greyhounds about to chase a hare. Locals say nearly everyone in the town races.

But Perez says hanging is not peculiar to Medina and with the shelter, dogs that would probably otherwise be killed are saved, at no charge to the owner.

He reckons that in other parts of rural Spain, for example Andalucia, hangings are much more common.

This year some 200 dogs have been handed over to Perez's shelter. Two men turned up at the end of January with an injured dog and asked to swap it for another one.