That is a great question, that , in spite of sending several horses to trainers, has not crossed my mind, really. The last trainer tho, required mortality on any horse he takes. I think that is because he lost a barn full of reiners back in the 80's. Other than that, I have always assumed, my horse-my responsibility-but, I am always actively involved with the trainers I hire, too. I am there as much as humanly possible. THis trainer-about a week a month, but they have a system by which an assistant is in charge and intimately knows each horse, which is why when he coliked a month ago, they really caught it early. Most-I am there at least 3-4 times a week. I can be pretty confident that if something happens it would have happened with me or them, and is part of horse ownership. However-I do not own a really pricey horse. The insurance and answer may then be different.