Vitamin C

[Sarah Ralston <ralston@AESOP.RUTGERS.EDU>]

I was one of the first to suggest Vitamin C for stressed horses and
have done a fair amount of research on it over the past few years.
I am glad others have picked up on it. I do differ from the previous
recommendations, however, in that, based on my research and other studies,
preloading before the animal is actually stressed does absolutely no
good and may even be a detriment. Vitamin C has limited "storage space"
in the body (adrenal glands and, in mares, the ovary) and any excesses
are rapidly excreted in the body. Since most horses make more than
enough vitamin C in their liver to meet their needs, giving them high
levels (5-10 gms twice a day) they don't need merely gears them up to
excrete it.

Based a recent study, for a horse being transported long distances or
chronically stressed, 10 grams vitamin C twice a day and 1600-2000 iu
Vitamin E
(for the average 1000 lb horse-we used half those amounts in our research
foals),
starting even after the transport is over but maintained for at least 5
days AFTER,
improves their immune system, based on incidence of "shipping fever" type
respiratory disease 
and immune response to a vaccine three weeks later. However, this was based
on only
ten weanlings transported from North Dakota to NJ in a 38 hr trip,
half received vitamins for 5 days AFTER arrival, the other half only
received the 
"carrier" (applesauce-which they all loved!).  We are repeating this study
this
year, using 12 foals, again half supplemented, half not,
all from the same place, hanmdled the same and on the same trailer,
 just to make sure what we saw was real. This year we will give them a 
dose immediately before transport, but again, these are recently weaned,
half wild horses and I think they are already under a fair amount of stress.
Will let you know how it turns out. 
I also personnally add Brewers Yeast during periods of stress, without any
good equine
science to back me up, but stress does also deplete the B-vitamins in other
species.
Plus it's cheap and won't hurt... :-)

Sarah and Fling (Brewers yeast again? Yuck!)