Zeolite use for diarrhea: effectiveness and study results

At some point, we wanted to know exactly what was going on with the diarrhea.

Many horse owners report how well their horses recover from diarrhea with zeolite – we at Steinkraft have also gained much of this experience over the years. But at some point, that was no longer enough for us. We wanted to understand more deeply: What exactly happens in the horse's intestine? And what does science actually say about it?

That's why we conducted our research – thoroughly, mindfully, with an open heart and a sharp mind. We scoured specialist articles, studies, dissertations, and practical experience, not only on horses, but also from cattle, pig, and poultry farming. Zeolite has been used successfully for years wherever the intestinal imbalance is present.

Here you will find the results of this search: a collection of scientifically proven findings on how zeolite works in the digestive tract – binding toxins, protecting mucous membranes, stabilizing stool consistency, and promoting healthy intestinal flora.

Because when it comes to our horses, it’s not just feeling that counts – but also sound knowledge.

What is diarrhea – and what makes it so special?

Not all diarrhea is the same. While diarrhea causes the entire stool to liquefy, horses with diarrhea usually display apple-shaped stools – but a brownish fluid also drains from the anus. Sometimes in astonishing quantities. It's not an emergency, but it's a silent signal: Something's wrong.

Diarrhea is often the result of a chronic imbalance – whether due to stress, feeding errors, poor hay quality, dental problems, lack of exercise or microbial shifts in the intestine.

How does zeolite work in the horse’s intestine?

Zeolite is a natural volcanic rock with a special property: its crystalline structure acts like a sponge. It can bind excess acids, toxins, fermentation gases, mycotoxins, and even heavy metals. At the same time, it soothes mucous membranes, has an antioxidant effect, and supports the restoration of inner balance. We learned all this from Prof. Dr. Karl Hecht.

What do studies and scientific articles say about zeolite?

The study situation on zeolite in horses is still young – but there is a wealth of data from livestock farming (calves, piglets, poultry) that allows conclusions to be drawn.
Here is a scientifically sound overview – I have organized the studies into four thematic areas: pollutant binding, intestinal mucosa, stool consistency, intestinal flora.

1. Toxin binding in the intestine

Sources:

• Cerbu et al. (2020) examined 80 calves with diarrhea. One group received an additional 2% clinoptilolite supplement in their feed. After just 8 days, stool consistency improved significantly, and diarrhea incidence decreased significantly. Furthermore, body weight remained more stable than in the control group.
  Source: DOI: 10.3390/ani10122284

• Katsoulos et al. (2016) analyzed dairy cows fed aflatoxin-contaminated feed. Adding 1% clinoptilolite significantly reduced the level of aflatoxin M1 in the milk, demonstrating effective toxin binding in the digestive tract.
  Source: DOI: 10.1016/j.anifeedsci.2016.03.001

• Ortatatli et al. (2005) conducted a histological study of chickens exposed to aflatoxins. The zeolite group showed less liver damage and better overall health.
  Source: Research in Veterinary Science, 78(1):61–68

2. Soothing the intestinal mucosa

Sources:

• Wu et al. (2013) used zeolite in broiler chickens. Results: significantly reduced inflammatory markers (e.g., TNF-α), increased villus height in the small intestine, and increased levels of antioxidant enzymes such as glutathione peroxidase. This indicates a regenerative effect on the intestinal mucosa.
  Source: Poultry Science 92:684–692

• Valpotić et al. (2016) examined piglets fed 1% clinoptilolite. The animals exhibited increased intraepithelial lymphocytes and a more stable mucosal structure. Furthermore, the proportion of pathogenic bacteria in the feces decreased.
  Source: Veterinarni Medicina 61(6):317–327

• Bartko et al. (1995) : In a large-scale study with 2,223 calves, the addition of 5% zeolite to the diet reduced the diarrhea rate from 68.7% in the control group to 18.0% in the zeolite group. Furthermore, the mortality rate decreased from 4.7% to 1.3%.
  

3. Stabilization of stool consistency

Sources:

• Cerbu et al. (2020) (see above): In addition to toxin binding, the study also confirmed a measurable improvement in stool texture – without any medicinal additives. The researchers conducted an in vivo study on 80 milk-fed calves with diarrhea. One group received a micronized clinoptilolite powder (5 µm particle size) in their feed for 8 days, while other groups served as controls (antibiotic, tannin extract, untreated).
  Result: After just one week, the prevalence of diarrhea decreased significantly in all treated groups , including the zeolite group. While 100% of the calves had diarrhea at the beginning, at the end of the observation period the rate of persistent diarrhea in the zeolite group was significantly reduced (similar to the antibiotic-treated calves) The authors evaluate clinoptilolite as a safe and effective treatment for symptomatic diarrhea in calves and as a possible alternative to reduce antibiotic use.
  

• Sadeghi & Shawrang (2008) conducted a double-blind study on newborn Holstein calves. Calves fed colostrum with zeolite suffered less from diarrhea, had a lower bowel movement frequency, and improved daily weight gain.
  Source: Livestock Science 113:307–310

• Norouzian et al. (2010) gave lambs 3% zeolite for 30 days. Results: significantly firmer feces, fewer coliform bacteria in the feces, and improved weight gain.
  The researchers examined newborn lambs that received different levels of zeolite in their milk replacer for 6 weeks. With a 3% clinoptilolite supplement, the lambs showed firmer stool consistency and a lower severity of diarrhea than the control group. At the same time, these lambs gained weight better (+ weight gain) and there were no negative effects on blood count or health parameters. The authors concluded that zeolite can reduce diarrhea-related losses and improve performance in lamb rearing
  Source: Small Ruminant Research 91:170–173

• Valpotić et al. (2016) (see above): In the same piglet study, the average diarrhea score decreased significantly compared to the control group. In the aforementioned study on 40 weaned piglets, a feed supplement of 0.5% clinoptilolite resulted in significantly fewer diarrhea symptoms . The total diarrhea score (over 14 days after weaning) was significantly lower in the zeolite group than in untreated piglets. In addition, the bacterial load in the small intestine was reduced (decreased total bacterial count in the jejunum) , indicating improved intestinal hygiene. Interestingly, in another study (Song et al., 2014, J. Anim. Sci. 92:173–182), experimentally induced diarrhea in piglets was also alleviated by clinoptilolite – the animals had higher serum IgG levels and lower E. coli excretion, although weight gain remained unchanged. .
  
  These consistent results support the idea that zeolite binds excess fluid in feces and stabilizes intestinal function. Applied to horses, this means that a suitable zeolite supplement could help thicken thin fecal fluid and normalize the overall consistency of the feces.
  

4. Promote a healthy intestinal flora

Sources:

• Wu et al. (2013) (see above): In addition to mucosal benefits, a favorable microbiota shift was also observed: fewer E. coli, more Lactobacilli in the intestine.

• Song et al. (2014) conducted a randomized study with 96 piglets. The zeolite group showed not only an increase in IgG in the blood (improved immune status) but also a significant reduction in pathogenic bacteria.
  Source: J. Anim. Sci. 92:173–182

• Lojkić et al. (2017) analyzed over 70 sources in their review. They describe zeolite as naturally antidiarrheal, growth-promoting, pH-stabilizing, and immunomodulating. (Periodicum Biologorum 119:159–172)

And yet every horse remains an individual.

As convincing as many of the scientific findings are, they are no substitute for looking at the individual animal. Diarrhea isn't a symptom that can be "cured" with a single remedy. It's often an interplay of husbandry, feeding, stress, intestinal flora, and sometimes even internal history.

Zeolite isn't a miracle cure, but it is a powerful, natural ally.
It can relieve the intestinal environment, stabilize digestion, and gently support the organism. And that's exactly what many horses need: inner grounding, calmness within the system—and a human who listens.

The studies confirm what many have already felt: nature works.
Quiet, deep and sometimes more complex than you think.