Rectal tears are relatively common in horses after rectal examinations for diagnosis of gastrointestinal disorders or reproduction. We present the case of a mare that was freely bred and started with colic 8 hrs later. A rectal tear was produced by accidental rectal penetration of the stallion penis with a secondary septic peritonitis. Conservative medical treatment was made. Four days after the accident, the mare presented repetitive colic episodes that were associated with a huge hematoma that almost close the rectum lumen and caused feces retention.

Key words: Hematoma, Mare, Peritonitis, Rectal tear