I've been working in stable management for over 20 years, and have my stall
cleaning down to a fine art. I've noticed at many big barns that have mats
in the stalls, they often don't used a shovel to scrape the wet spot up; they
just pull the dry shavings over it, and kind of mix them in. The places
that clean like this, combined with a tightly closed up barn, will end up
smelling like urine even if the stalls look clean. It sounds like the barn
mentioned doesn't have much turnout for the horses, meaning they are peeing in
their stalls more. I'm fanatical about clean stalls....left one barn
because he only picked manure during the week, and then stripped everything on
the weekend. By Wed or Thurs the smell would knock you down. Think
of those poor horses with their delicate lungs having to inhale that all
night!!