The district court on the Baltic island of Gotland ruled that the man did indeed kill the mouse, something he was unwilling to admit himself.
However, the court found that the death of the mouse was quick and that the 23-year-old had no intent to cause the creature undue suffering, local media reported on Wednesday.
The charges stemmed from an incident recorded on a mobile phone camera back in April in which the 23-year-old is seen holding the mouse by its tail.
Encouraged by his friends, the man then bit the head off the mouse before spitting the head out in his hand, while blood drips from the rodent’s lifeless body.
The man then stuffed the headless body of the mouse back in his mouth.
“Look, look, the mouse is lying and shaking!” one of the man’s friends can be heard saying in the background.
Prosecutor Anna Beckman said she plans to appeal the verdict to the Svea Court of Appeal.
Her main witness, veterinarian Torsten Jacobsson, maintains that the man had to struggle and tug with his mouth in order to get the mouse’s head off and that the creature died a terrifying death.