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Articles on Psyllium Use and Benefits

8 Horse Colic Take-Homes from the ESS Symposium

Surgeon Dr. Anthony Blikslager shares his perspective on preventing horse colic.

Posted by Alexandra Beckstett, The Horse, Managing Editor

The Horse (

Every two years, the Equine Science Society (ESS) holds a symposium covering the latest equine nutrition and physiology research. Anthony Blikslager, DVM, PhD, Dipl. ACVS, professor of equine surgery and gastroenterology at North Carolina State University, in Raleigh, kicked off the 2019 edition, taking place June 3-6 in Asheville, North Carolina, with his perspective as a surgeon on horse colic prevention.


Here are eight interesting facts from his lecture:

1. Equine veterinarians can’t tell what type of colic (e.g., ileal impaction, large colon volvulus, etc.) a horse is experiencing based on clinical signs alone. What they can determine is when medical treatment isn’t working and when signs are getting more severe—both of which suggest a horse might need to go to surgery.

2. Colic treatment has been made more complicated by barn managers and caretakers having access to pain-relieving non-steroidal anti-inflammatory drugs (NSAIDs), such as phenylbutazone (Bute) and flunixin meglumine (Banamine), on the farm, Blikslager said. These drugs can give them the impression that clinical signs have resolved when, in fact, they haven’t. Ideally, owners should be notifying their veterinarians when administering an NSAID, said Blikslager. And as a rule of thumb, he said, horses should respond to the first round of NSAID treatment. If they need a second round, the veterinarian should discuss with the owner referral to a hospital.

3. The major themes in colic prevention revolve around feeding (forage type and quality) and management (meal frequency, parasite control, housing/stalling, etc.). “Managing these can help prevent colic in the future,” said Blikslager.

4. Colic prevalence is sometimes associated with horses consuming coastal Bermuda hay, which is commonly grown in the Southeastern United States. In fact, a 2002 study found horses fed coastal Bermuda hay were six times more likely to develop ileal impaction than horses fed other grass hays. Colic treatment has been made more complicated by barn managers and caretakers having access to pain-relieving non-steroidal anti-inflammatory drugs on the farm. Dr. Anthony Blikslager presented one theory as to why, emphasizing it hasn’t yet been proven: “Coastal hay is much finer, stemmier hay. If horses aren’t used to it, they don’t chew it properly and unintentionally swallow longer fibers than they should. This can clog the ileocecal junction like hair in a drain.”

5. Horses pass approximately 150 liters, or 40 gallons, of fluid through their gastrointestinal tract each day. Meal feeding, in particular, causes massive fluid fluxes through the digestive tract, essentially dehydrating and rehydrating the large intestine repeatedly, which can put horses at risk of colon impaction.

6. On average, food travels 20 meters (about 65 feet) through the horse’s stomach and small intestine and into the cecum and large colon fairly rapidly—within two to three hours. This means concentrate feeds enter the colon relatively undigested, said Blikslager, triggering microbiome changes and the large fluid fluxes mentioned above.

7. Psyllium is a popular daily supplement for preventing sand colic in horses that graze on sandy soils. In theory it reduces sand levels in the gut, but Blikslager said it might act more like a prebiotic, which gets digested by the microbiome within the colon. This could, in turn, result in increased short chain fatty acids, which might have positive effects on the microbiome and gut motility, thereby speeding sand passage.

8. Broodmares are at risk of large intestinal strangulating obstructions post-foaling. Blikslager hypothesized reasons for this: the big physiological changes that take place right after foaling (i.e., more space in the abdomen); significant changes in exercise levels as mares are stalled to foal, then turned back out; nutritional changes during lactation; and microbiome changes. He said this latter cause is a promising future research focus.

Take-Home Message

In sum, Blikslager said owners and veterinarians must learn to better recognize horse colic risk factors (e.g., foaling, hay type, etc.) and focus on management changes such as feed quality to prevent the condition from developing. Researchers should continue to study the significance of the microbiome and refine optimal management practices revolving around feeding and turnout.

Source-The Horse (

Psyllium Mucilloid Effective In Removing Intestinal Sand

Posted by Stephanie L. Church, Editor-in-Chief,

The Horse (


Horses living near a coast or in the warm desert sun might seem to have a luxurious life, but many equines in these areas are threatened by abdominal sand on a daily basis. These occurrences were a problem for a group of veterinarians.


Horses living near a coast or in the warm desert sun might seem to have a luxurious life, but many equines in these areas are threatened by abdominal sand on a daily basis. These occurrences were a problem for a group of veterinarians from Arizona Equine Medical and Surgical Center (AEMSC). Those practitioners studied 24 horses suffering from intestinal sand between 1991 and 1993. This previously unpublished study reported that psyllium (horse-strength Metamucil) could be an effective means of eliminating sand from the gut of a horse. This contradicts a study that said psyllium is ineffective for helping a research pony rid sand placed in his cecum.


Mark Revenaugh, DVM, was a collaborator in the Arizona study. He now works with B.W. Furlong & Associates veterinary firm in New Jersey. Revenaugh explained that many horses ingest sand on a daily basis in the Phoenix Valley, and he recalled cases where up to 50-60 pounds of sand were found in the right dorsal colon. “(In surgery) you had to be careful that you didn’t tear the colon–it was like picking up a bag of concrete,” he said.


Veterinarians are not sure why the horses ingested the sand, but Revenaugh said there were no indications that horses had a mineral imbalance that might have caused the consumption. In fact, questionnaires returned by the horse owners did not verify any significant management issues that would contribute to such behavior except that they were fed at ground level.

After seeing so many horses suffering with a virtual beach in their GI tract, Revenaugh, Gayle Leith, DVM, MS, ABVP, and Kent Allen, DVM, (now of Virginia Equine in Middleburg, Va.), all of whom were practicing at AEMSC at the time, began a study that involved 24 horses suspected of suffering from intestinal sand build-up. Symptoms were abdominal discomfort (38% of the admitted horses), weight loss (38%), or diarrhea (24%), all with sand in the manure and characteristic abdominal sounds. All diagnoses were confirmed by observing sand on abdominal radiographs, and each horse underwent a full physical examination. Horses were started on a daily dosage of psyllium, then evaluated monthly.

Although the mechanism of action is uncertain, it is suspected that psyllium acts as a bulk laxative. “If you take (psyllium) and wet it, it almost forms a gelatin-like substance, which seems to blot up the sand,” explained Leith.

It’s believed by these veterinarians that these “globs” of gelatin-like substance, which form readily, move accumulated sand out of the system. Revenaugh explained that psyllium works differently than bran, another laxative. In fact, more of the horses in the study had been fed bran prior to the study than not.

According to Revenaugh, 63% of the horses showed a “marked decrease” in intestinal sand seen radiographically after one month, and 91% improved after two months of psyllium treatment. The statistics didn’t change significantly during the third month, other than virtually cleaning out the sand. Findings suggested that most horses in the study cleared virtually all abdominal sand after three months of psyllium therapy. Most horses’ initial symptoms were resolved long before sand was completely eliminated, suggesting there’s a threshold of sand accumulation before clinical signs appear.

It was recommended that the 9% of study horses which did not respond to therapy be kept away from sand completely. Revenaugh said he thought those animals were ingesting sand at the same rate it was eliminated. In fact, one horse ate sand so ravenously that sand volume actually increased during the study. After hospitalization and aggressive psyllium treatment with a nasogastric tube, virtually no sand was detectable clinically or radiographically in four days.

However, a study presented at the 1998 American Association of Equine Practitioners Annual Convention found that psyllium was ineffective for normal ponies which had sand surgically placed in their cecum. They reported that 70% of the sand was passed whether the ponies were treated or not.

While the studies had different outcomes, both recommended limiting access to sand to prevent ingestion.

Source-The Horse (


Psyllium for Glucose and Insulin Control

Posted by Erica Larson

The Horse (

Veterinarians often recommend psyllium for use as a laxative, specifically for clearing sand out of horses’ intestines to minimize the chances of sand colic. But research indicates, there might be another use for the phytogenic (plant-based) supplement: the control of blood glucose and insulin concentrations.


Research performed in humans indicated that oral psyllium supplementation reduced blood sugar and insulin response after eating, but psyllium’s effects on horses’ blood glucose and insulin levels had not previously been examined. Shannon John J. Moreaux, DVM, assistant professor of equine science at Montana State University, and a team of researchers set out to determine whether psyllium would have the same effect on horses.

Both insulin and glucose play a role in equine insulin resistance (IR), a hormonal disorder that most commonly occurs in horses with equine metabolic syndrome and in those with equine Cushing’s disease (pituitary pars intermedia dysfunction, PPID). Insulin’s main function is to control blood sugar (glucose) levels by signaling fat, muscle, and liver cells to take up glucose (a simple sugar resulting from the digestion of food) from the blood and store it as glycogen (stored complex carbohydrates–essentially, a main source of fuel for the horse). Insulin resistance is a reduction in a horse’s sensitivity to insulin that makes it harder for the fat, muscle, and liver cells to transport the glucose out of the bloodstream and store it as glycogen.

The team employed 16 stock horses (eight mares and eight geldings) that were 7 to 16 years old. The horses were healthy with no known medical or soundness conditions. All of the horses were fed a diet of mixed grass hay and a commercial whole grain feed twice daily. Moreaux and colleagues separated the horses into four groups, each containing two mares and two geldings. Each group received one of the following supplement courses:

  • 90 g of psyllium per day;

  • 180 g of psyllium per day;

  • 270 g of psyllium per day; or

  • An isocaloric control (an untreated control group).


The psyllium pellets were added to the horses’ daily grain rations for 60 days. On Day 60 the researchers fasted the horses overnight and drew a blood sample before feeding the next morning’s rations. After they fed the animals their normal morning feed, team drew blood samples every 30 minutes for six hours to monitor the horses’ glucose and insulin levels.

Upon reviewing their results, the team found that the horses that received psyllium for 60 days had lower average blood glucose levels after feeding and lower average peak glucose levels. Additionally, the psyllium-fed horses had lower average post-feeding insulin levels and lower average insulin concentrations than the nontreated control horses. Of the horses that received psyllium, the dosage made only a minimal difference on the levels of glucose and insulin present in their bodies.

"Psyllium could be especially beneficial to obese, insulin-resistant horses, or horses that are predisposed to developing laminitis because of metabolic syndrome," Moreaux said in the study. "It is commercially marketed and readily available to horse owners, and when fed daily, may help to maintain lower postprandial (post-feeding) blood glucose and insulin levels."

The researchers noted that additional trials that encompass "larger populations of horses, obese horses, and horses exposed to pasture forages" would be beneficial to further the understanding of the supplement’s effects.

The study, "Psyllium Lowers Blood Glucose and Insulin Concentrations in Horses," was published in the Journal of Equine Veterinary Science.

Source-The Horse (

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