I've been watching The Original Series and on any occasion when Mr Spock has some health issues McCoy seems either baffled or unable to help him without taking risks or being completely unable to predict Spock's reactions to whatever treatment he can provide.
I wonder why the Enterprise would have a chief medical officer who doesn't understand the biology of a member of the crew. Shouldn't all doctors aboard be perfectly capable of treating all of their patients regardless of their biology?
Is that mentioned at any point in the series later? Is this common with other medical officers in other series?
