Thoracic duct is a duct that drains the lymph from the cisterna chily into the venous angle of the cranial vena vava. Thoracic duct in the horse is situated on the right side, but in rare cases the left thoracic duct has been reported. In this report the course and left position of the thoracic duct in an embalmed donkey is described. Regarding many anatomical similarities between horse and donkey it seems that the existence of left thoracic duct in donkey should be considered as a rare condition.
Key words: anatomy, horse, donkey, thorax, thoracic duct.