A four-year-old racehorse has been found slaughtered at a ranch in the United States.

The owner of another horse at the Miami ranch discovered the black thoroughbred dead in his stall at about 7am on Wednesday, 9 September.

The horse had been brutally butchered, with its throat slit and front legs removed.

Police found no sign of forced entry to the ranch and are trying to contact a security guard who usually stays at the property until 5am.

Animal rights groups and the police fear the horses are being butchered in order to sell the meat on the black market.

The remains of at least 17 slaughtered horses have been found in Miami-Dade County since January.

In May, two horses were found in a field in Miramar with their throats cut and flesh stripped from their legs.

According to the South Florida Society for the Prevention of Cruelty to Animals, the last known horse slaughter occurred at the end of July.

Sergeant Bill Bamford, of Miami Gardens’ police, told a local paper that they were in contact with forces in other counties to look into the similarities between the cases.

The Humane Society of the United States is offering a $10,000 reward for information leading to the culprits.