Originally Posted by middleofnowhere
How about training your dog and not having him anywhere near livestock unless you are out there with him?
The OP was very frustrated today. They chose NOT to use a tool they had, instead coming here to ask for (and I quote directly) "Ideas", obviously to train and manage the situation. They asked for others with personal experience in this situation to offer suggestions also.
Posts like yours, which are condescending at best, offer the OP nothing in the way of help, but serve to immediately set a defensive and/or negative tone for the thread.
In the limited information the OP gave, you really have no idea whether the dog is trained or not. A dog can be training successfully, even proofing successfully and suddenly meet a "new" challenge that has not been considered or the dog has never seen before. I don't see anything in the OP's post that said the dog was unattended (as you insinuated) or necessarily untrained.
My dog's recall is very very good--we're continually proofing and proofing. However, I can tell you that considering what I do with him, it's high odds that someday he will meet a bear or possibly even a cougar, and very high odds that he will meet a moose. While I can practice and practice and practice, I actually can't tell you what he will really do if he meets one of those animals, because they're a little hard to "proof" with. If he ran after the cougar and ignored my recall, even after months, years of perfect recall off deer, and I were to post about it, would you then suggest to me "training" my dog?
Things aren't a problem for people until they are.
OP, MRL's post has some very good information. You can also keep your dog on a long line and practice training around your horses, starting far enough away that the dog is not distracted, and then moving closer and closer, as the dog's success allows. If he's focusing on them instead of you, you're too close. If you can practice in the cow pasture, too, at some point, that may help as well. Otherwise, with the cows, recall training will be your best bet, as well as just acclimating him to them, so they become not as interesting and rather boring to him.