sorry for only now responding to posts from this past weekend.
"Karen Thomas" [EMAIL PROTECTED] wrote:
> ...I seem to remember hearing that...not all "SE" is actually caused so
much by the cullicoides as by a bombardment of many minor allergies...
Won't that make it harder for a single vaccine to work for all cases of SE...?
You are 100% correct that the immune system of an imported horse must be
assaulted by a whole array of things that it never encountered back in Iceland,
when it was distinguishing "self" (what it shouldn't mount an immune reaction
to) from foreign epitopes (all else, that it should mount an immune reaction
to). Nonetheless, culicoides' saliva is is by far the worst offender. Indeed,
it seems a real testimony to the imported Iceys' adaptability that they do not
develop horrible allergies to a lot of different things. So my guess is that
it should eventually be possible to develop a desensitization regime for the
offending culicoides antigen (or antigens). However, as you know,
desensitization (like in humans for bee stings or poison ivy) takes quite a
long while, and during that time the patient shouldn't be exposed to that
antigen. Therefore, to be best effective, such a desensitization protocol
would need to be administered in Iceland before import, or only import in the
late fall and do the desensitize treatments all winter and spring, before the
horses here get exposed to massive amounts of those bugs. Or maybe,
eventually, horses in Iceland that are being raised for export will be
administered culicoides' antigens when they are newborns, so their immune
systems will consider that "self" and not later raise an allergic reaction to
it.
However, in lieu of those routes, I am quite certain that one can mimic such
a desensitization protocol by making sure that culicoides antigens are
introduced only very slowly, following the horse's import. That is the
reasoning behind being totally fanatic about protecting their immune systems
against a full culicoides exposure for the first few years the horses are here,
from the first warm days to the first good frost, e.g., by spraying with
FlyGone EVERY AM and PM for the first few years and then daily spraying
thereafter. Possibly stabling with a chest high fan every dusk and dawn, and
probably also all day if it is humid, cloudy, and breeze-free, could work as
well.
Unfortunately, for Iceys imported into a high-culicoides area (such as
Anneliese's and ours, and probably yours as well), the very BEST in normal
horse care, and using the BEST in normal bug protection, does not limit
exposure to culicoides antigens, favoring the eventual onset of SE. I found it
most interesting when Malin ("Ingvar Ragnarsson") posted that 80% of iceys
imported to Holland eventually develop SE. This meshed very well with
Anneliese's observations and with our more limited observations here in
SE-conducive microclimates.
Whatever, SE is nasty, but an affliction where most if not all horses can be
kept comfortable, generally lesion-free, by rigorous application of now-known
treatments (e.g., FlyGone; dusk/dawn stabling with a chest high fan; Boett
blankets; dex treatments if all else fails; SE lotion or some other effective
salve if there should be an outbreak). it certainly is much brighter for these
horses than it was only 5 years ago!
yours, Barbara
in Maryland
p.s. Finally, I must apologize for not being clearer when talking about horses
born in a SE-free area and then brought as adults to SE-central, which several
vets have told me have a markedly increased chance of developing SE, for the
same reasons as Iceys. However, their chances of developing SE are still not
nearly as high as for imported Iceys. Possibly this difference is because of
all the other assaults on the imported horse's immune system, as you described,
and/or that horses elsewhere in the US grew up with some related bugs.
