Re: Se levels

[CMKSAGEHIL@aol.com]

In a message dated 98-09-30 09:58:44 EDT, mathew@redhorsetech.com writes:

<< For selenium, the normal range is 0.09 to 0.30 mg/L concentration
 (plasma) in adult horses.  Deficiencies are considered at less than
 0.065 mg/L, while an excess may occur at greater than 0.3 mg/L
 concentration in plasma. >>

Actually, most recent work (am quoting from Schering's lab, and I see many
others are adopting this, too) indicates that normal is .20 to .25 mg/L (or
200 to 250 ppb, depending on what units the lab uses to report), and that .15
to .20 is considered marginal.  I have never seen .065 considered anything but
deficient, even in earlier days--old figures from Oregon State considered
normal to be something like .15 or .17 up to .25, and marginal to be something
like .12 to either .15 or .17....  Clinically, I get pretty concerned if I see
levels anywhere below .17 or .18 or so.  Horses below that are prone to tying-
up episodes (if they work), immune dysfunction (especially if they are
babies), and retained placentas and rebreeding problems (if they are
broodmares).

Heidi Smith, DVM--Sagehill Arabians (Oregon)