Hawker Koh Seng Hong, 50, was sentenced to eight months' jail on Monday for punching a taxi driver in the face twice after the driver had run over his friend's chihuahua.

Mr Ling Ah Yen, 67, sustained multiple fractures in the head after the altercation, which occurred after he had run over the small dog at Ang Mo Kio Street 12 on Feb 8 this year. Koh was drinking beer with his friend, chef Toh Meng Teck, 40, and his friend's girlfriend. Mr Toh had brought along his pet chihuahua, Lucky. The couple and Koh left separately at 1am. Mr Toh raised his hand as the couple crossed the road, and Mr Ling slowed down.

But he did not see the chihuahua, which was not leashed and had run under the taxi, the court heard. The aggrieved Mr Toh started shouting vulgarities, attracting the attention of Koh, who then rushed over. Koh, who is married, heard the taxi driver comment in Hokkien that "it was just a dog".

In mitigation, defence counsel S S Dhillon argued that the animal lover was provoked by the "casual" comment, and the attack was "most unfortunate and totally out of line with his character". In sentencing Koh to eight months' jail, District Judge Lee Poh Choo found that Koh's reaction "far exceeded the circumstances", and that the dog owner was not blameless as he had failed to leash the chihuahua. She also agreed with the prosecution that Mr Ling was "not reckless", because he had slowed down to let Mr Toh cross the road.