Two horses were left injured after they were attacked in their field.
Police said the animals were left with facial injuries and that a garden fork was "found discarded within the field".
The incident earlier this month happened on land in Hemington Hill, Hemington, near Castle Donington, reports Leicestershire Live.
Officers from Leicestershire Police have appealed for anyone with information to come forward.
They also posted some photos of the animals' injuries - some of which were too graphic to publish.
The incident happened between 7pm on Friday, January 15, and 11am the following day.
A police spokesman said: "Were you within the area during these times? Have you seen anything that maybe connected to that above?"
Anyone with information is asked to contact the force on 101 and quote incident number 21000038802 and leave details for PC 237 Holme.
The incident provoked a reaction from members of the public on social media.
One user said: "What is wrong with people? Poor things."
