Neighbors Loose Dogs Barking And Approaching Horses Aggressively

I board my horses on a large property with a field in the back to ride in which used to be super fun and enjoyable until the neighbors purchased two large livestock guardian dogs. Now whenever we ride past their house the dogs run down the hill onto our field and bark at the horses. This naturally scares many of the horses on the property as the dogs are very big and loud and charging toward us. Thankfully the dogs haven’t attacked anyone or gone past running out and barking, But it has made riding very scary for me and my horse. They are young dogs with little to no training and i am scared that it will escalate to an attack and be bad news for a horse, dog, or person. I have talked to the horse property owners and they said there is nothing they can do because Colorado is a fence out state so in order to keep the dogs away they would need to fence the entire field with would cost insane amount of money. My happy place is gone and I am at a loss of what to do.