Text: Hannah Botha, MSc
In the realm of equine nutrition and health, every horse owner aims to provide the best care possible for their beloved steeds, and that extends to supplementing their diet according to their needs. Among the various supplements available on the market, psyllium is getting increasing attention as a noteworthy inclusion in equine diets, but what is it, and why is it used?
Understanding psyllium
Psyllium husk is derived from the seeds of the Plantago ovata plant. It provides soluble fibre, which is commonly used in both human and veterinary medicine. As it contains high levels of mucilage, a gel-forming fibre that absorbs water, it swells to form a gel-like substance in the digestive tract.
Benefits for equine digestive health
One of the primary reasons for incorporating psyllium into a horse’s diet is the theory that this gel-like substance effectively removes sand particles in the gut, thereby mitigating the risk of sand colic, particularly common in horses kept in sandy areas.
It is also thought that horses suffering from recurrent episodes of diarrhoea or loose stools could benefit from psyllium’s bulk-forming effects, which help absorb excess water and normalize stool consistency.
Psyllium husk is also rich in fermentable fibre that promotes butyrate (which is a short-chain fatty acid) production in the hindgut. Intestinal cells utilise butyrate as an energy source. When these cells are ‘happy’ and well-supplied with butyrate, they can be repaired and regenerated, improving overall gut health.
Recent studies have proposed the theory that psyllium could also help control glucose and insulin, which would benefit horses struggling with certain metabolic conditions.
But does the science back this up?
Psyllium and sand
In terms of sand clearance, the science is very variable. One specific study by the University of Colorado State found that adding a psyllium product did not improve sand clearance compared to a control group. A study in Finland found that psyllium and magnesium sulfate did improve sand clearance. However, in this study, psyllium was fed at a rate of 1g/kg of body weight per day for four days; this would be 500g per 500kg horse – a lot more than customarily suggested). Following on from this, when 500g of psyllium was fed alongside mineral oils, a huge variation was seen in clearance between individual horses.
Sand accumulation
Several studies have interestingly demonstrated that psyllium supplementation is not a 100% effective strategy for sand clearance. However, the most effective sand clearance strategy for horse owners turns out to be feeding free-choice hay, or at least 2.5% of the horse’s body weight per day
Besides feeding free-choice hay, the most effective strategy to mitigate sand accumulation is to prevent sand ingestion from occurring in the first place. Feeding in buckets and off the ground, while preventing overgrazing of sandy paddocks are all effective ways of reducing sand colic risk.
Psyllium and insulin control
Horses who received psyllium for 60 days had lower average blood glucose levels after feeding and lower average peak glucose levels. The psyllium-fed horses also had lower average post-feeding insulin levels and lower average insulin concentrations. Interestingly, of the horses that received psyllium, the dosage (90, 120, or 250g per day) only made a minimal difference in the levels of glucose and insulin present in their bodies.
This suggests that psyllium could be beneficial to obese, insulin-resistant horses or those predisposed to metabolic concerns, but larger populations of horses, obese horses, and horses exposed to pasture forages need to be studied to understand its benefits further.
Administration and dosage guidelines
Dosage and administration should always be discussed with your vet in cases of digestive disturbance. Psyllium is typically administered orally in the form of a powder or granules, which can be mixed with the horse’s feed. The dosage varies depending on the horse’s size, weight, and specific needs.
As a general guideline, based on some of the scientific studies, up to 500g per day, split into separate servings for five consecutive days per month for an average 500kg horse for sand clearing, can be beneficial.
On the other hand, for horses with a history of digestive issues, a daily administration of one heaped dessert spoonful twice a day is advised.
Ideally, the product should be mixed with dry feed (or slightly dampened immediately before feeding), as adding larger amounts of water or fully soaking feed can lead to swelling before eating, which can be an issue for some horses.
While psyllium is generally safe for horses and well-tolerated, certain precautions should be observed. It’s crucial to ensure that the horse has access to ample fresh water when consuming psyllium, as adequate hydration is necessary to facilitate its passage through the digestive tract. Additionally, psyllium should not be administered concurrently with medications or supplements, as it may interfere with their absorption.
Note
Horse owners should always consult with a veterinarian before initiating psyllium supplementation, especially if the horse has preexisting medical conditions.
Final thoughts
It seems there is a role for psyllium in some horses. However, caution must be exercised and a vet consulted before the product is administered.