A giant squirrel got inside my fort and scratched a dwarf's head and finger, tearing apart the chin whiskers and the hair, along with smashing a nail. The head was later sutured (by fairly inexperienced doctors).
In another occasion, while gelding rams (because why not?) the gelder took an unlucky kick on the head, tearing apart the upper lip and chin whiskers. Again, the head was sutured.
Throughout the years, I've noticed that my water reservoir was steadily decreasing, even though I had enough booze. It turns out that these two dwarves are taking seasonal baths due to pus accumulating on their heads, which Dwarf Therapist then showed as being infected.
What exactly are the effects of infections? I've read that they slowly deplete the dwarf's blood, but DFhack's gm-master shows that their blood is always at maximum, even though one of them has a meager 368 recuperation stat.
Do hair wounds ever heal? Looking at the health tab on these two dwarves' status screen shows that the hair and whiskers are still torn apart, after DECADES have passed since the wound. These parts shown as injured never received treatment, only the head, as a general part, got the sutures. Also, the one with an injured finger still hasn't recovered his nail, nor ever got treatment on it.
What are the benefits of more skilled doctors? I'm under the impression that unskilled diagnosticians/suturers/etc perform the exact same as legendary ones. All the wiki says is that higher skill reduces chance of infections, and I'm not even sure if it's during or after the procedure.