It's par for the course.
Do you know how they collect the urine? Do they catherize them or bag them or what?
Never mind. I read on a site where they are strapped with rubber bags. A horse could get used to that. What did concern me was "small stall" but small is in the eye of the activist so I went on. The thing that troubled me the most was that the poster stated that the horses are denied free access to water to concentrate the hormone. That is unacceptable to me and setting the horses up for infections and health problems.