NO child should ever be left alone with ANY dog, and I don't care if the dog is Lassie. Actually, no child should be left alone with any animal. Period.
Dogs do not see kids the same way as they see adults and often don't accept authority from them. They will often discipline them as they would other dogs.
Most dogs don't like being hugged around the neck. Many may tolerate it , but they don't like it.
Society now seems to think dogs should be like Disney characters instead of what they are - predators and carnivores who are well equipped to defend themselves.
A case in point is Labrador retrievers, who are near the top of the list for bite cases, particularly towards children. This is not because they are bad dogs, but because people think of them as totally harmless and leave children alone with them. "Oh, it's a Lab so it's o.k."....NOT
Children and dogs are the victims of careless and ignorant adults.