Courtney Capps, 27, of Burleson said she was shocked when an emergency department physician at Huguley Memorial Medical Center wrote out the paddling prescription for her child earlier this year, the Fort Worth Star-Telegram reported Monday.
The doctor also asked her son, being examined for an infection on his finger, about his race, she said.
"You can't make a racial remark to my child and then write a prescription" like this, Capps said.
Capps filed a complaint last week with the Texas Medical Board against the physician, Dr. Carl W. Gossett.
A hospital spokesman said the incident was immediately brought to the attention of the emergency room medical director.
"Appropriate action was taken," Kurt Ademie said, adding the physician no longer practices at Huguley.
During the examination, Capps said the doctor, who is white, asked about the child's race.
Capps, who is white, told the doctor her son was biracial.
Caps said the doctor then said, "What does your family think about that?"
"I just looked at him like, you've got to be kidding me," Capps said.
Gosset could not be reached for comment, but his wife, who asked not the be named, told the Star-Telegram her husband asked about the boy's race because of possible genetic predisposition to certain diseases.
"It wasn't meant to be racially negative," she said.
He wrote the paddling prescription as a lark, she said.