Image copyright Getty Images Image caption The Chihuahua, like this one pictured in Japan, was only a puppy

A man in the US territory of Puerto Rico has been jailed for biting the head off his girlfriend's dog.

Luis Arroyo was sentenced to seven years in prison after pleading guilty to mistreatment of an animal and domestic abuse.

The 40-year-old attacked the two-month-old Chihuahua puppy and punched his girlfriend in the western mountain town of Lares on 4 February.

Judge Carlos Lopez Jimenez also fined Arroyo $3,000 (£2,400) in the case.

According to El Vocero newspaper, jobless Arroyo had been living with his 38-year-old girlfriend for six months.

The puppy died instantly, the daily reports.

No motive was given for the attack.