The average horse will go through seven different owners in it's 25-30 year lifespan. I felt a tug to see exactly where this slave trade happens and to document these horses in holding, before they were passed along to their next owner. 

Recently the barn I board my two girls at had owners who were sending their pony to auction. They had bought him to be a riding horse for their eight year old boy, but once they brought him home they realized the previous owner likely sedated him for the videos they saw of him riding around calmly. I've learned that this is not an uncommon practice in the horse world. Sedating, or giving a horse a high dose of pain medication before pushing them through the auction ring for the hope of a sale rather than providing care, a forever home, or humane euthanizatia. 
Some people who buy in bulk to flip and resell take their chances knowing a few will have been under a facade of health, only to have them examined then euthanized after buying them when they deem their conditions not worth the flip value. 

I passed the eight year old boy at the barn and he shared with me that they were selling his pony that night at the auction. I asked if he was feeling sad about it. He shook his head and said "No. He bucked me off this morning, so he's gotta go." 

Another casual day at the auction for observers, buyers, and sellers. But to these horses, their fate was in the hands of humanity.