The animal reportedly bit the baby on his head on Monday while the family was at home, police and prosecutors announced Tuesday.
The cause of the animal’s attack, as well as its history of aggression, is unknown.
The dog, reportedly a mixed-breed of dogs known for their fighting ability, was brought to an animal shelter following the attack. While in the shelter, the dog was described by workers as displaying aggressive behaviour, reported a police spokeswoman.
According to the police announcement, the father of the young boy immediately contacted the emergency services after the biting incident, and medics then took the child to an emergency clinic.
At first, the baby's condition remained stable, but the infant died the same evening due to his injuries. Prosecutors in the town report the child’s parents as being in a state of shock.
Local police secured further evidence at the scene on Tuesday morning.
Vet in Hanover mauling case under investigation
The veterinary office of the Hanover District Court may face penal and employment consequences for not acting on earlier reports of increased hostility from Staffordshire mix “Chico”, Hannover councillor Axel von der Ohe told the Hannoversche Allgemeine Zeitung on Monday.
As early as 2011, the veterinary office had received evidence of increased aggression of the dog from the Hanover District Court, reports indicate.
A legal guardian of the family had reported these incidents of aggression to the Hannover court.
Included in evidence is a psychiatric report claiming that the 27 year old son was mentally unable to care for the dog. He also refused to comply with a court ordered appraisal of the animal after the earlier incidents, a problem which the veterinary staff did not followed up on.
“It is hard to explain why the indications we had received were not followed up,” said von der Ohe.
The issue of Chico’s future also remains unclear, as Hannover officials decide if the animal should be euthanized or kept permanently in a special facility.
As of Monday, an online petition calling for the dog’s life to be spared had reached over a quarter of a million signatures, said the animal shelter where Chico is being held.
The decision about Chico’s life rests on whether or not authorities believe she still poses a public danger. Shelter officials said that they have not reached a final decision.