The man was detained at Cahir Garda Station under the provisions of Section 4 Criminal Justice Act 1984. Following questioning, he was released without charge on Friday morning.
As part of the investigation, gardai are working closely with the Department of Agriculture and Tipperary County Council.
A file is currently being prepared for the DPP and investigations are on-going. Anyone with any information should contact Clonmel Garda Station at 052 6177640 or the Garda Confidential Line 1800 666 111.
The incident occurred at the Heywood Road, Clonmel on Wednesday at around 4pm and was filmed by a passing motorist.
The graphic video shows two young men releasing a young horse from a sulky, who then collapses to the ground and is dragged to the side of the road.
The video, which has been viewed over 50,000 times, has been condemned on social media.