A reward for information is being offered after a horse was found dead in a field in East Sussex last month.
The 18-month-old animal, called Rascal, was found in a field at the top of Kings Ride, Alfriston, on 24 October.
Tests on the Blue Roan Blagdon Cob showed it died from deliberately inflicted multiple injuries.
The People for the Ethical Treatment of Animals (Peta) put up a £1,000 reward for information leading to the conviction of those responsible.
"Animal abusers are cowards," said Peta spokesperson Suzanne Barnard.
"They take their issues out on the most defenceless beings available to them."
The injuries to the horse, which were mostly internal, are thought to have been inflicted by a sharp object.
The animal also suffered a large laceration to its face and neck.
Two other horses that were in the field at the time were uninjured.