Sand Colic: A Prevetable Problem
Hinder
sand build-up in the horse’s digestive tract through
proper management.
By
Sandi Lieb, PhD, Associate Professor Emeritus University
of Florida
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In
the sandy soil areas in the Southern U.S. as many as 30% of
all equine colic cases have been traced to sand buildup in
the GI tract. Poor management practices have been suggested
as a major factor in these types of colic; however, few controlled
experiments have been done to determine sand intake causes,
or the effectiveness of the management and veterinary sand
removal methods being used. This article summarizes seven
separate trials which were conducted over a 5 year period
at the University of Florida, including a 12 month field study
and many controlled experiments with 4-8 horses each. Sand
intake and feeding or treatment conditions were strictly controlled
and voluntary sand intake or fecal sand output levels were
measured.
Here is a brief description of the trials and their results:
Farm Field Trial
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Grab
fecal samples were taken from more than 30 horses on five
local farms over a one year period. There was a high horse
to horse variation in the percentage of sand found in the
feces, with some horses having consistently higher amounts.
There were no seasonal or farm differences. Some of the
farms were feeding their horses in buckets or tubs on open
sandy areas. No sand colic cases were reported during the
collection period. |
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Controlled
Sand Removal Trials
Controlled sand removal trials using mature horses (8 horses
in two trials): Six treatments were tested over the two
trials including dosing with mineral oil via stomach tube,
single feeding of wheat bran, feeding of psyllium either
one time or daily for 6 days, and feeding 1.5 or 2.5% of
body weight (BW) hay. In all cases the “control”
or basic feed ration was the 1.5% of BW of coastal bermudagrass
hay (15-20 lbs for 1,000 to 1,300 lb horses) and sweet feed
supplementation which met each animal’s nutrient requirements.
Sand (300 or 500g, approx. .7 or 1 lb) was given with water
to each horse via stomach tube just before the oil, bran
and psyllium treatments were applied. There were no statistical
differences between these treatments or the control in their
ability to remove the sand. Sand outputs peaked mostly on
day 2 post-dosing/treatment and 45-95% of the sand was recovered
in the feces by 5-6 days post-dosing. The horse to horse
variation was large; however, the ‘control’
(hay only) treatments consistently removed the greatest
total quantity of sand and the 2.5% BW hay treatment removed
almost twice the sand (95%) by day 6, as the other treatments.
Feeding of psyllium 2x daily (about .5 lb of psyllium per
day) for 6 days appeared to suppress sand passage through
the tract. Psyllium has been reported in the veterinary
literature since the 1970’s as being useful to remove
sand from horses’ GI tracts; however, a review of
these reports show that each of them were of a few individual
animals already exhibiting sand load symptoms and each was
treated by stalling and dosing with psyllium. No control
animals were ever used to compare with the psyllium in any
of these reports. The trials reported here indicate that
if the animal is removed from further sand intake then normal
feeding (with or without any treatment) would remove the
sand. One recent paper with a control but a different technique
found that psyllium had no effect on sand removal just as
our trials have found.
Controlled
voluntary sand intake trials
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| Controlled
voluntary sand intake trials using mature horses (4-8 horses/4
trials): management factors including eating grain (sweet
feed) on sandy surfaces, eating different kinds of hays on
sandy surfaces, varying the hay to grain ratios from 0.75
to 2.25 and feeding diets deficient in either or both energy
(75% of requirement) and protein (70% of requirement) were
studied. The greatest sand intakes (up to 1-2 lbs per feeding)
occurred when the horses ate their grain ration directly on
sand or retrieved grain dropped onto a sandy surface. But
the amount of sand taken-in varied greatly from horse to horse. |
Studies
have shown that traditional methods of preventing sand colic
are no more effective than simply feeding an adequate amount
of hay. |
Some
horses were observed taking in pounds of sand each feeding
in their attempts to retrieve every kernel of their grain
ration, while other horses stopped eating once they got to
the sandy surface and therefore took in much less sand.
This individual horse difference might account for why on
the same farm under the same feeding conditions one horse
might accumulate heavy sand loads, and thereby, be more likely
to get sand colic while others do not. Unexpectedly, literally
no sand was taken in when grass hay (Coastal bermudagrass)
was fed on dry, sand surfaces, and only small amounts with
legume hays (alfalfa or perennial peanut). Also, some individual
horses had large voluntary sand intakes (sand was offered
free choice in a bucket) on the trials looking at various
hay to grain rations and energy/protein deficiencies but no
treatment differences were found. As reported previously in
the literature, some horses were observed to eat their own
feces when on low protein or low forage diets. Diarrhea has
been reported in the veterinary literature as a common occurrence
in horses carrying heavy sand loads in their GI tract; however,
no diarrhea was observed in any of these trials. Take
Home Message
First, it is very important to reduce or help prevent sand
intake by not feeding grain where it can come in contact
with sand. This is especially important for individual horses
that appear to search-out and consume every dropped kernel,
whether their own and or dropped grain from others in their
feeding group. Placing rubber mats which are kept free of
sand under feeding containers should help keep grain separate
from ground sand. Apply special sand avoidance management
to those individual horses that appear to consume sand of
their own volition by stalling them in matted stalls and
turning them out only in paddocks with good grass cover.
In some cases you may want to evaluate the diet you are
feeding—it might be insufficient in fiber/hay, major
nutrients, or out of nutrient balance for your horse. In
some areas like Florida, it is almost impossible to keep
a horse free from some sand intake. Therefore, the most
effective and economical method for keeping sand moving
through the horse’s GI tract and to prevent sand buildup
is to make sure that their daily feed ration contains a
minimum of 1.5% BW hay intake (15 lbs/1000 lb horse). Feeding
of 20+ lbs (2+% BW) is even more effective and free choice
feeding of the forage (pasture or hay) is the best and most
natural and has many behavior benefits. If you know that
a horse has taken in and is carrying an excess sand load,
then it is best to remove the horse from access to any sand
and keep it on an ample hay diet for a period of a week
to give the accumulated sand time to be evacuated. No advantage
was found for applying the three common sand removal treatments
tested (mineral oil, wheat bran or psyllium) over a diet
of sufficient hay. So save your money trying to use these
methods and put it into buying more hay!
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PERCENTAGE
OF RECOVERED SAND BY TREATMENT METHOD
AT 5-6 DAYS POST DOSING WITH SAND |
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| The
most effective way to prevent sand colic is to provide
horses with 1.5% to 2.5% of their body weight in hay
daily. For example a 1,000 pound horse should be provided
with a minimum of 15 to 25 pounds of hay each day. |
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Publications:
Lieb, S. 1997. Sand Removal From the GI Tract of Equine,
Proceedings of the Fifteenth Equine Nutrition and
Physiology Symposium, p.335.
Lieb, S. and J. Weise. 1999. A Group of Experiments
on the Management of Sand Intake and Removal in Equine.
Proceedings of the Sixteenth Equine Nutrition and
Physiology Symposium, p.257.
Weise, J. and S. Lieb. 2001. The Effects of Protein
and Energy Deficiencies on Voluntary Sand Intake and
Behavior in the Horse. Proceedings of the Seventeenth
Equine Nutrition and Physiology Symposium, p.103.
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