An 8-month-old boy was attacked and killed Thursday by his grandmother's pit bull, police said.

Jordan Lee Parker died of massive head injuries at the family's home, said Nacogdoches County (search) Sheriff Thomas Kerss.

The pit bull, which had no history of aggressive behavior, had been tussling with another pet, a smaller terrier, when it attacked the boy, Kerss said.

He said the boy's grandmother was trying to separate the animals when the dog grabbed the child by the head.

Kerss said the dog freed the child within seconds, but he was dead by the time authorities arrived.

Family members told authorities the pit bull had lived with them for 14 years without incident.

Kerss said the grandmother requested that the pit bull be euthanized, and the dog was taken to an animal shelter.