latrine vs litter box

latrine

noun
  • An open trench or pit used for urination and defecation. 

  • Any facility or device used for urination or defecation, whether toilet, lavatory, or outhouse. 

litter box

noun
  • A box used to provide a soiling area for (usually) pet cats, generally filled with kitty litter, sand, clay chips, etc. 

How often have the words latrine and litter box occurred in a corpus of books? (source: Google Ngram Viewer )