One thing I have found to help in long distance
hauling is an underlay material that goes under the hard rubber floor mats. It
is a foam type of material I special ordered from the Trailer dealer. It makes
it much springier and softer. It seems to absorb the shocks of the road much
better. In addition I use shavings to soak up pee and poop.
We unload every 5-6 hours. My trailer has an
insulation package and that seems to keep the heat down in the summer much
better than my old uninsulated rig. It is important to let them graze and
get their heads lowered at rest stops.
The fairground idea mentioned is great. We hauled
from Missouri to California and back this summer and used fairgrounds almost
every night. It was cheap ( $5-10 for two horses and plugging into
electric), plus we turned the horses into the arena after the 4-H kids left.
Most of the time they spent the night in a roping pen or something larger than a
stall.