After writing that it should say something like 'Cheats enabled.' When it has said that, just start typing in the commands! In order to do this you need to open up your cheat bar (CTRL + SHIFT + C) and write 'testingcheats on'. So here it is! The commands to REMOVE or ADD your pets irrational fears and obsessions of random objects! Or even better? Wish your dog was loud? Wish it was quiet? Wish your pregnant cat didn't throw up everywhere? Wish it slept in an adorable little ball instead of on its back? HERE YA GO! Just keep reading! You've all been searching for it! Or at least google says you have, and so have I! And I found the answer!
