The child and dog were struck by a silver 2005 Ford Explorer around 9:30 a.m. on Sheridan Road north of Chaney Avenue , according to the Lake County (IL) Sheriff's Office.
The child was being transferred to Lurie Children's hospital in critical condition.
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The 29-year-old driver did stop at the scene and was not hurt. The Sheriff's office also said the driver is cooperating with the investigation.
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No other details have been released at this time.