The incident took place late Friday afternoon at a mobile home park along State Route 168 in Hanover Township.
The boy was flown to Children’s Hospital in unknown condition.
Investigators say the children are not related, and that the dog was taken to be quarantined in Lawrence County.
The news crew went to the home of the little girl but they didn't want to talk. She was not injured.
The incident is under investigation by State Dog Warden Jennifer George.
(CBS Pittsburgh - April 9, 2017)