A court has been told a man tried to chop off a cat's head but had only wanted to end its suffering.

Video of the gruesome incident was posted on the internet, Adelaide Magistrates Court heard.

The court had been told Adrian Pomorski, 26, repeatedly hit the cat with a shovel but had wanted to spare it from any further cruelty.

His arrest came after South Australian police were shown a video of the incident.

It was alleged Pomorski was laughing during the attack.

The cat has not been located and it is unclear whether it died as a result of the attack.

Pomorski's lawyer John Dillon told the court the cat had been mistreated by its owner.

He said his client wanted to end its suffering with a single blow and not cause it any pain.

The prosecution urged that Pomorski be jailed.

He will be sentenced in February.