Grigroe Vlad attacked the animal in the Calverton area, on April 6.
Vlad, 41, of Cope Street, Walsall, denied causing unnecessary suffering to the sheep when he appeared at Nottingham Magistrates Court, on August 3.
But he was found guilty after failing to turn up for a trial on December 18.
He also admitted motoring offences in Arnold, on April 6, and failing to surrender to police after his release on bail.