I have a 3 year old Thoroghbred gelding who has been drooling for the past couple of months.It is quite severe and it looks like it is partially digested hay that he is drooling out and I know that horses cannot bring things back up. He has had his teeth done and has been eating hay all year. He does not have choke but I was reading some stuff about eating clover and black patch fungus that could cause that. I'm in northern alberta and I don't know if that is something common up here. He has also been on two different types of hay and it hasnt seemed to make a differnce. He has no other symtoms of anyhting, he has good weight and is nice and shiny and always comes for his oats at night. He is the only horse out of 33 that is doing this and they all eat hay that was baled from the same two feilds. I would love some input if anyone has heard of this.