Muscle Twitching in QH

[Maurisa Payne <maurisap@erols.com>]

Hi group -

Before I begin the above subject, let me clarify a thread that is being
sent around this group.  A fellow poster has been lumping my name in
with hers (i.e., "Maurisa and I....") without my permission regarding
the animal byproducts issue.   For the record - I do not agree with her
extreme views and I'd appreciate my original post - which simply passed
along interesting reads from Newsweek and a book - be judged solely on
its own.  Thanks!

Now my question - I have an almost 4 year old foundation QH gelding that
I've had since he was six months old.  He has this strange twitching
syndrome that affects various areas of his body - shoulders, flank,
neck, etc.  It worsens in hot weather and when put under exertion (it is
not from twitching flys).  He does not appear to be in any discomfort
when twitching.  My equine vet, a well known endurance rider, examined
him last fall during an episode and wanted to proceed with blood and
urine studies.  She had been called to my barn for several things
happening to several horses - so this was not the primary focus of her
visit.  My QH would not cooperate regarding a urine sample, so we
decided to first test him for HYPP since he is a registered QH (though
he does not go back to Impressive).  He tested N/N for HYPP.

We were going to pursue the other studies but I ended up laying him off
the light work he was doing because he had a mild ligament injury.  I
note with interest that his twitching was not apparent over the cold
winter.  I change the diets of my horses during the winter months by
switching from orchard grass to Timothy hay, adding one flake of alfalfa
(east coast hay), and adding a small amount of cracked corn to their
sweet feed.  I don't know if it is coincidence that the twitching
stopped.

It's now getting warmer here so about a month ago I discontinued the
alfalfa and the cracked corn.  They are still on Timothy and sweet feed
and have always had free access to a salt and mineral block.  Yesterday
when I went to the pasture to visit my equine friends while they were
sunning themselves I noticed that his twitching has come back - while he
was simply resting in the sun.  He did seem a bit more lethargic
yesterday.  Before I begin expensive testing - does anyone have any
ideas or experience with this type of thing?  I'd appreciate suggestions
because I'd really like to get this boy started on trail riding, but I
don't want to cause him harm in any way.  Thanks for your input.

Maurisa