Re: Respiratory rate and thumps

[CMKSAGEHIL <CMKSAGEHIL@aol.com>]

In response to the thumps question, I am not an expert on thumps, but would
like to say that I have seen a tremendous difference over the years in horses
and their tendency to thump and have come to the conclusion that some
individual a) are not very efficient with their electrolytes, and b) have a
much lower tolerance for an imbalance before the phrenic nerve becomes
affected and begins to thump.  I also see this problem cropping up in certain
family lines, so think that there is a genetic tendency toward this lack of
efficiency and/or intolerance.  The problem is caused by electrolytes crossing
the nerve sheath and allowing electrical currents from the heart to "fire" the
phrenic nerve, which serves the diaphragm.  Debby, I would try to test this
horse, and see if there is a calcium problem or other electrolyte problem, but
keep in mind that it is not something that you will "cure"--only manage.  Yes,
I think the hyperventilation might be related and significant.  Keep in mind
that each horse has his own electrolyte metabolism and the "right"
supplementation ranges from none at all to megadoses.

Heidi Smith, DVM--Sagehill Arabians (Oregon)