berserk vs mad-dog

berserk

adj
  • Furiously, injuriously, or maniacally violent or out of control. 

  • Bizarre; weird. 

  • Wildly joyous; ecstatic. 

noun
  • Synonym of berserker (“a Norse warrior who fought in a frenzy”) 

mad-dog

adj
  • Fanatically or irrationally ferocious. 

How often have the words berserk and mad-dog occurred in a corpus of books? (source: Google Ngram Viewer )