Garland Independent School District spokesman Chris Moore said the teacher, whose name was not released, was teaching a lesson on cowboys at Schrade Middle School in Rowlett when he asked for student volunteers to run around while he attempted to lasso them, WFFA-TV, Dallas/Fort Worth, reported Wednesday.
Moore said a 13-year-old student ended up with bruises on his neck when the lasso landed on him incorrectly.
"This is not something that we feel was malicious, it was not intent," Moore said. "Extremely unfortunate, and extremely poor judgment."
Moore said the Garland Independent School District placed the teacher on leave as a precaution.
The Rowlett Police Department is investigating the incident for possible criminal charges.