Is My Horse Ok Or Sick ?

I have a 3yr old Cob he`s not been broken-in yet I love him I see him everyday he`s new to the stable`s i boarded him in he`s in a field with 2 other horse`s 2 mare`s (He`s a Gelding) I take him out everyday groom him pet him take him to the arena for some work and sometimes take him to the lake at the stable`s the horse`s in the field don`t like him he has no friend`s lately he has his ears down all the time he`s eating properly and look`s healthy it just worries me that he has his ears are always down is he sick or is it just because he`s new ?