An action against a physician, surgeon, dentist, hospital, sanitarium, registered nurse, licensed practical nurse, chiropractor, or other practitioner of the healing arts for malpractice, error, mistake, or failure to cure, whether based upon contract or tort, can be commenced only within two years after the alleged malpractice, error, mistake, or failure to cure shall have occurred, provided, a counterclaim may be pleaded as a defense to any action for services brought by a physician, surgeon, dentist, hospital, sanitarium, registered nurse, licensed practical nurse, chiropractor, or other practitioner of the healing arts after the limitation herein prescribed, notwithstanding it is barred by the provisions of this chapter, if it was the property of the party pleading it at the time it became barred and was not barred at the time the claim was sued or originated, but no judgment thereon except for costs can be rendered in favor of the party so pleading it.
This section shall be prospective in application only.