A newborn baby boy has been killed by the family dog in his parents’ bed.

The youngster was attacked after the American Staffordshire terrier-Great Dane cross breed was startled by the boy’s mother coughing.

The three-day-old baby and the dog were with the boy’s parents, who were sitting in bed watching TV, at the time in their home on the outskirts of San Diego, California.

Sergeant Tu Nguyen, of San Diego police, said the coughing caused the dog to unexpectedly bite the baby.

He said the parents were able to pull the animal off the child and take him to hospital, but he was pronounced dead on arrival.

Sgt Nguyen, a member of the child abuse unit, said: “At this time, we’re looking at this as nothing more than a tragic incident.”

A post mortem examination is under way to determine the cause of death.

The dog, a two-year-old named Polo, is being held in quarantine to determine whether it has rabies.

Deputy director of the county Department of Animal Services Dan DeSousa said it will be up to the owners to decide its fate.