It is the opinion of some vets that all horses will take in some sand; most
will pass it quite happily (so finding lots of sand in the manure may be a
good thing rather than a bad thing because it means the sand is coming
through). The problem arises when the sand stays in the gut. I have heard
some opinions that consider parasite control to be as important as sand
control, as the worms can damage the gut and disturb normal motility,
leading to sand accumulation. Bacause the sand is heavy and falls to the
most ventral part of the gut, you can actually hear it if you put your
stethoscope right underneath the belly, at the midline, around the part
where the ribs join onto the sternum. The sand swishing around on itself
sounds a bit like listening to waves on the beach. (The first time I head it
I had to look up in the sky because it sounded like a plane going over!).
As far as shifing sand, psyllium does seem superior to paraffin oil and some
of the other remedies, but should be used with caution as it can make the
horse colicky (as the sand shifts), or could, as some respondents have said,
form a glob inside the gut.
Anne
Murdoch University
Western Australia