spit feathers vs vent one's spleen

spit feathers

verb
  • To feel very angry; to sputter angrily. 

  • To feel very thirsty. 

vent one's spleen

verb
  • To openly express pent-up anger, often on an unrelated matter or person. 

How often have the words spit feathers and vent one's spleen occurred in a corpus of books? (source: Google Ngram Viewer )