[RC] [RC] selenium toxicity - Alice Yovich - Sherman
I found some info from the archives
which might help you to determine if you were even giving enough selenium
to be toxic. Of course, it also depends on what the levels were to begin
with and what is being ingested from the hay/feed. Also, found a
website with good info here http://www.ruralheritage.com/vet_clinic/selenium.htm . I seem to recall, but can't find it now, that damage from
selenium toxicity is irreversible. Anyone else know about this?
Kathy
From the
archives:
Regarding selenium: The daily requirement for
selenium is 8-10 mg. The level necessary for chronic toxicity is 60-90
mg/day over a several week period. It is a lot harder to achieve this
than a lot of people think, especially for those of us in deficient
areas. A kg (kilogram) is only 2.2 pounds. One has to do the math
when one is serving an amount different than the "per kg" or "per
pound" listed on most labels to figure out how much of any one nutrient there
is.
Most feeds labeled as "high selenium" still only contain 2 to 2.5 mg
per recommended serving, because that is all that FDA will allow
feed manufacturers to add. In other words, if you live in a deficient
area, one of these feeds will only provide one-quarter of your horse's daily
requirement. In other words, you have to add considerably more than what
these "enhanced" feeds contain.
Too much selenium can cause problems
with losing mane and tail hair, and in extreme cases, also sloughing of the
hoof wall. Acute high doses at critical times of pregnancy can cause
malformations in the fetus. However, deficiency is a far more common
scenario. Deficient horses are less thrifty, more prone to immune
problems, more prone to rhabdomyelitis (tying-up syndrome), and a whole host
of other problems.
