medicine and canon law
The practise of medicine and surgery is forbidden to the clergy, except by Apostolic indult.
This prohibition embraces all grades of the clergy, as well as all religious and their novices.
A cleric would not infringe on the law, however, were he, in case of necessity, to use knowledge that he has, nor would he be considered to be practising if he were to suggest some simple remedies.
Even though one receives an indult to practise medicine, a special permission is needed to practise surgery.
Religious charged with the care of hospitals have permission to practise medicine through the approval of their rule.
New Catholic Dictionary