Comparisons

Probiotic vs Yeast Supplement for Horses

Live bacteria or live yeast for the hindgut. What the research supports, what survives the journey, and when neither is the right purchase.

Please read: This content is researched for general information only and is not professional, medical, or veterinary advice. Every situation is different, so use your own judgment and double-check before acting, especially when adding chemicals or feeding and treating animals. Consult a qualified professional when in doubt. This page also contains affiliate links; we may earn a small commission at no extra cost to you.

The short version

Live yeast, particularly saccharomyces strains, has the better body of equine research behind it, mainly around fibre digestion and stability in horses under stress or on high concentrate diets. Bacterial probiotics are widely sold, but the evidence in horses is thinner and there is a real question about how many organisms survive the stomach in a useful state. Both are best thought of as small adjustments. The hindgut is a forage fermenter, so the change that reliably improves it is more long stem forage, fewer large grain meals, and gradual feed transitions rather than any tub of powder.

Widely sold

Farnam Probiotic Powder for Horses

About $34

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Better equine evidence

FullBucket Equine Probiotic Pellets with Saccharomyces boulardii

About $44

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At a glance

Farnam Probiotic Powder for HorsesFullBucket Equine Probiotic Pellets with Saccharomyces boulardii
Organism type Bacterial cultures Live yeast
Equine research base Limited Better, especially on fibre digestion
Survives the stomach Variable by product Generally better
Common use case After antibiotics, feed changes Stress, travel, high concentrate diets
Cost per month Moderate Moderate to higher
Replaces good forage management No No

Choose the Farnam Probiotic Powder for Horses if…

A bacterial probiotic is a reasonable short course after a course of antibiotics, around a feed change, or through a stressful period, if your vet thinks it is worthwhile. Check the label for the organisms named and the guaranteed count at the end of shelf life rather than at manufacture. Store it as directed, since heat kills live cultures and a tub left in a hot tack room is not delivering what the label promises.

Check Farnam Probiotic Powder for Horses on Amazon

Choose the FullBucket Equine Probiotic Pellets with Saccharomyces boulardii if…

A live yeast supplement is the better supported option for supporting fibre digestion, and it is commonly used for horses travelling, competing, or on diets heavier in concentrates than an ideal forage based ration would be. Introduce it with a feed change rather than in isolation, so you can see the effect. As with any supplement, add up what the horse already receives, because senior feeds and balancers frequently include yeast and you can end up paying twice.

Check FullBucket Equine Probiotic Pellets with Saccharomyces boulardii on Amazon

Related

Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these products side by side. Confirm current specifications and prices before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.

Editor's Pick · Affiliate link

Cosequin ASU for the Older Horse

The joint supplement with the most research behind it in horses, combining glucosamine and chondroitin with avocado and soybean unsaponifiables. Worth starting before an older horse is visibly stiff rather than after.

Frequently Asked Questions

Will a probiotic fix loose manure?

Sometimes it helps, and sometimes it delays finding the actual cause. Persistent loose manure in an older horse can indicate sand accumulation, parasites, a diet too high in starch, dental disease preventing proper chewing, inflammatory bowel disease or PPID. Free faecal liquid is common in older horses and can be frustrating to resolve. Get a veterinary opinion, including a faecal egg count, before spending months on supplements.

Does my horse need a probiotic after antibiotics?

It is a reasonable precaution and commonly recommended, particularly with antibiotics known to disturb the hindgut, but ask the vet who prescribed the antibiotic. Some antibiotic reactions in horses are severe, and any horse that develops diarrhoea while on or shortly after antibiotics needs urgent veterinary attention rather than a supplement.

What actually keeps the equine hindgut healthy?

Forage available for most of the day rather than in two large meals, minimal starch, gradual changes over ten to fourteen days whenever anything alters, clean water, and a parasite control programme based on faecal egg counts rather than a routine calendar. Those cost less than supplements and have far more behind them. For an older horse who cannot chew long forage, a properly formulated hay replacer fed in several small meals does the same job.

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