Luis Arroyo, 40, bit off the head of his girlfriend's Chihuahua, and then punched her in the face.
Authorities said Tuesday that a judge also ordered Arroyo to pay a $3,000 fine in the case that included domestic abuse and mistreatment of an animal.
The incident occurred in February around 3:30 in the morning on a weekend in the western mountain town of Lares.
The municipality is located about an hour-and-a-half from San Juan.
According to Primera Hora, the two had been living together for about six months, and he had no history of domestic abuse.
Arroyo, who is unemployed, was unable to originally post his bail which was set at $400,000.
He is now being held at Las Cucharas Correctional Complex.