Endophytes/Fescue Toxicity...

Gwen Dluehosh (dluehosh@vt.edu)
Fri, 10 Jan 1997 22:15:06 +0500

HI Jorene...
Fescue hosts a "bug" called an endophyte that causes problems in pregnant
mares. I don't know the exact mechanism (will be reviewin git again
shortly...) but it causes problems with placentas and foals primarily... Its
main effects are lengthening the gestational period of mares to way beyond
the due date- it interferes witht eh normal hormone cycles of mares and
foals near parturition.
It also thickens the placenta and causes retained placentas and problems
with foaling.
THis can lead to failure of passive transfer (ie no antibodies) if the foal
isn't as responsive as it should be(ie not nursing), and also there is
usually a problem with milk let down. I believe we had a very mild case this
summer, all was fine, but I missed one of my mare's foaling (and this from
someone who WAITS by their bedside for the foal!) We found the mare and foal
in the morning, and got them put up and observed. The foal nursed but there
was absolutely NOTHING in the udder, and we could not determine if it was
cause the foal was suckling or if it was becasue there wasn't any. At any
rate, I hadn't expected the mare to foal this early (which is kind of
opposite what I said). We ended up dragging the foal and mare to the Vet
school after giving her Domperidone (no it's not champagne! :) ) to
stimulate milk letdown. We did a CITE test on the foal and found he DID have
IgG of almost 800, (that's good!) so figured she must have produced enoguh
colostrum for the foal in spite of our doubts. We had estimated his birth
time as just about dawn, so less than 12 hours later he had antibodies
showing up... Some say not to do the test till at least 18 hours...

At any rate, unless you know your fescue is free of endophyte (you'd have to
know the bag of seed that actually went on the hay field and it would have
been certified endophyte free) avoid it at all costs for mares... It's
better to have grass hay or timothy or somesuch that doesn't carry the
endophyte...

Domperidone is an experimental drug that is in testing phase right now I
guess, ther e is some paperwork involved in using it under vet's
supervision, but as far as I know the vets are allowed to carry it if they
agree to do the paperwork.
(Basically simple stuff like history of horse, foaling and side effects)
There are no known side effects...at least not at the doses it is used at,
and it works amazingly well. Mare had plenty of milk in just a day or two.
We never had to give the foal any otehr supplemental source of colostrum or
milk.
Sorry this isn't "brief" but I hope it helps, feel freet oask questions if I
said something that isn't clear or is too scientific... Even I can't figure
everything out sometimes and get things too confusing for people
unintentionally.
Gwen
>> The only thing that looked hairy to me in your plans was that you have
>>fescue pasture and broodmares... I hop eyou are aware that fescue has
>>endophyte problems... I am sure you are if you have been keeping up with
>>this stuff here... :)
>>JUst one more opinion... from a vet student...
>>Gwen
>
>Well, since I only signed on a couple of days ago, and your
>reference to fescue & broodmares & "endophyte" problems is drawing a
>complete blank, would you mind giving me a brief summary? Thanks!
>
>Jorene :)
>
Gwen Dluehosh
Desert Storm Arabians
1156 Hightop Rd, #89
Blacksburg, VA 24060
540/953-1792