Case 5: Sand Colic


Living with horses in Florida has its perks, beaches, palm trees, and beautiful 70 degree days while the rest of the country is still locked in winter, to name just a few.  But calling this beautiful peninsula home comes with its own unique set of concerns.  One in particular, sand – that’s in your horse’s colon, not on the beach – is the focus of this month’s case.

Why would a horse eat sand?!  Small amounts of dirt and sand are naturally ingested as a horse eats.  Problems occur when more sand is eaten than passes through the GI tract and the sand accumulates.  This can occur for several reasons:

  • when management practices include feeding on or above sandy ground
  • when horses graze close to the ground in early spring and late fall when the first (or last) of the green grass is growing
  • when a horse is kept on a dry lot because access to green grass must be limited for health reasons
  • when not enough forage is provided, forcing horses to scavenge close to the ground for food

Once enough sand has accumulated in the colon, a horse will display typical signs of colic including pawing, flank watching, loss of appetite, and rolling (to learn more about colic in horses, see our colic page).  In addition, horses suffering from sand colic may also have an unthrifty or thin appearance, diarrhea, a mild fever, and a history of chronic colic episodes.

Meet Sissy:

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Like many horses in northern Florida, Sissy has pasture access and she is fed flakes of grass hay morning and night.   Knowing the risks of sand colic, Sissy’s owners have taken proper precautions by placing large rubber mats in the feeding area of each stall.  Grain is fed in buckets hung over the mats and flakes of hay are tossed into the center of the mats after daily sweeping away of accumulated sand.  Sissy and her herd mates also receive psyllium fiber as a feed supplement for several days every month in an effort to clear sand that has accumulated over time.

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In the picture above Sissy is with her herd mates outside of their barn.  Does this ground cover look familiar to some of you?

Last month Sissy has an episode of colic – her first one in the year her owners have been caring for her.  She was lying down more than usual, not interested in breakfast, and she had diarrhea.  When she started to roll, North Florida Equine was called.

Diagnosing sand colic starts with a thorough physical exam – and North Florida Equine did just that.   Suspicious of sand colic, she examined a fecal sample.  The feces were mixed with water and allowed to settle.  Sand is heavier than the rest of the fecal material and will quickly fall to the bottom of the mixing vessel (in this case a rectal sleeve).  The fingers of the glove with Sissy’s sample were almost completely filled with sand!

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Unfortunately, the “glove” or “mason jar” test is not 100% accurate.  It is not uncommon for a horse to be suffering from accumulated sand with no sand being passed in the feces – so the test will be negative even though sand is a major problem.  An x-ray of the colon is a very reliable method of diagnosing sand accumulation.  The sand that has settled to the bottom of the colon shows up bright white on film.  Unfortunately, this cannot usually be performed on the farm because portable x-ray machines are not powerful enough to penetrate the large size of a horse abdomen.  In the field, an abdominal ultrasound can aid in diagnosis by revealing the thickened colon that occurs in response to the mechanical irritation of the sand.  Often a thorough history, examination of the environment, and physical examination can gather enough information for a presumptive diagnosis.Once a diagnosis was reached, Sissy was treated with anti-inflammatories for pain and a nasogastric tube was passed.

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Water, electrolytes, oil, and psyllium were administered.  Psyllium is a soluble fiber that forms a gel mat in the intestine and assists in clearance of accumulated sand.  It also helps to re-establish the health of the colon after the mechanical irritation caused by sand.

Sissy’s treatment by nasogastric tube was repeated the following day.  Her owners continued to monitor her comfort level and her fecal output closely.  Sometimes sand accumulation can become so severe that the entire colon becomes obstructed or gas can build up and the colon can become displaced.  Luckily, Sissy did very well with her treatment and recovered on the farm.  If medical treatment had not resolved the colic, surgery would have been required to remove the accumulated sand.

Sissy’s owners thought they were taking proper precautions to prevent sand colic.  So what happened?  A closer look at their feeding method showed that the hay flakes were being moved around by the horses and much of the hay was being eaten off of the sandy ground.  Feeding psyllium fiber (often called “Sand Clear” or fed as “Metamucil”) may help – but it is definitely not a cure all.  Studies have shown that psyllium fiber does little to aid in sand removal – emphasizing the importance of preventing sand ingestion.

You now may be worried about your own horses’ ingestion of sand.  How do you prevent sand colic when the stuff is everywhere?  Here are a few suggestions:

  • feed hay and grain up off of the ground
  • if feeding on the ground, use large tubs that are cleaned out daily
  • place rubber mats below all feeding areas and sweep them daily
  • use a grazing muzzle for those horses that tend to “vacuum” the ground whether food is present there or not

Eliminating sand from the diet is easier said than done, but taking proper precautions can go a long way in preventing sand ingestion from becoming a problem.