The best replacement for cat is dog.

The best alternatives to cat are rated as following:
★★★★★  dog
★★★  human
★★  printer
★★  alligator
★★  snake
★★  dog game
★★  bear
★★  cat
★  dog diary
★  mailman
★  internet
★  dog person
★  dog quiz
★  kitten
★  fan
★  ceiling fan
★  baby
★  dog smarter
★  rat
  ferret
  rabbit
  dog games
  two
  paper army
  cummins
  dogs
  lizard
  dog first
  toddler
  bunny
  ravager
  gmat
  octopus
  mail carrier
  ct scan
  raccoon
  eagle
  dog yahoo answers
  polaris
  raptor
  goat
  dog video
  croc
  gate
  dog fight
  boar
  bald eagle
  metronome
  crow
  bieber
  girl cat
  bear video
  dog intelligence
  dinosaur
  dog the game
  fox
  gator
  feline
  cop
  iguana
  turkey
  sunroof
  mouse

Your alternative for cat is not listed? Suggest!
Speaking about cat, one probably shouldn't forget about hair.

Other search terms related to cat and their ratings are:
★★★★★ hair
★★★ grin
You have in mind a companion for cat and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of cat in all years. Click on graph for more.
cat
dog
human