Stamp letters here and organise handouts for domesticated animals, maybe (12)
I believe the answer is:
housetrained
If this is the answer, I'm afraid I cannot explain it.
Can you help me to learn more?
(Other definitions for housetrained that I've seen before include "(Of pets) not making a mess indoors" , "Unlikely to foul the carpet" , "(Of pet) taught not to foul indoors" .)