I got a new baby horse with out it's mom it has this modlit that says when..

I wouldn't know, I don't have that kind. I have the original sims 3, but I have an answer for you. While you're in-game, press left ctrl+shift+c and there should be a blue (or a white) bar on top of your screen. You enter testingcheatsenabled true or boolprop (which ever works for you) and then you right click on the moodlet you don't want and it poofs away. (you can also, with the cheat, select which career you want and what level you want it at. You can also force friends or visitors or you can type in motherlode to get money. But if you use motherlode you gotta do the testingcheatsenabled true or boolprop again.) sorry if this was too long... I hope I helped you

When a new foal has this emoticon, all you need to do is make friends with it! It doesn't work with pets and foals, only Sims and the foals.
It goes away as soon as you are friends.

Its really quite easy
You have to pet,rub neck,hug and all that stuff until it's says that it no longer feels unsafe

Ur sim needs to be the mother and if you hve a dog get it to be good friends with you're foal and tadaa you're horse is fine