People that have experience with horses only, please!!?

my stepmom and her friends were boarding horses at a stable for a few months. everything started out great ... then all of a sudden a couple of months ago everything got screwed. the owners of the barn refused to clean the horses stalls or let them outside. the only time the stalls were (and still are) being cleaned are thursday nights when a few ladies come and they want it to look good. my stepmom and her friend began sneaking around taking pictures of the disgusting stalls and the empty feed and water buckets every day. they are now suing them for a lot of money (for other reasons as well). my stepmoms friend has just discovered that her horse has developed lupus, which is incurable and most of the time, fatal. it is the owner's fault for neglecting these horses and triggering an infection. the owner is getting mad at people for coming to the barn to care for their horses cuz she wont. this is serious, does ANYBODY know any of the "acts" that can help us prove our case??? thank you