That must have been where I read it.
Probably. In The IDIC Epidemic, the Federation is trying to conceal information about a plague which doesn’t affect Klingons, only to find out at the end that the Klingons wouldn’t have used it as a weapon because the plague is deadly to their ruling class.
It was really good, and it was part of a set of two by Jean Lorrah. The first one was The Vulcan Academy Murders.