Police were alerted to the incident when neighbors called 911 at about 9:10 am.
Neighbors said they heard a woman crying and screaming.
"We are on Woodale Drive ... the dog got the baby ... some lady came to us and said the dog got her baby," the caller told 911 operators.
When officers arrived at the home in the 1200 block of Valley View St., they saw two large pit bulls laying beside the child.
For the boy's safety, a Greensboro police officer fatally shot one of the dogs after it moved away from the child.
The other dog fled, but was captured about four houses away and later euthanized.
Guilford County Animal Control is leading the investigation. Officials said the dogs belonged to someone in the neighborhood, but aren't releasing their names.
Animal Control said it is working with police and the district attorney to determine if any charges will be filed.
Witnesses said the boy was bleeding from his face and head. The boy was taken to Baptist Hospital for care.
His condition was recently upgraded from critical to serious.