The Safety, Tolerability and Efficacy of Probiotic Bacteria for Equine Use.
Authors: Cooke C Giselle, Gibb Zamira, Harnett Joanna E
Journal: Journal of equine veterinary science
Summary
# Probiotic Bacteria in Equine Practice: What the Evidence Actually Shows Probiotics are routinely recommended to horse owners for digestive health and performance, yet Cooke and colleagues' systematic review of 18 peer-reviewed studies reveals a sobering mismatch between popularity and scientific support. The researchers searched five major databases for evidence on probiotic safety, tolerability and efficacy in both healthy horses and those with gastrointestinal or systemic disease, critically appraising each study's methodology and outcomes. Most disappointingly, no credible evidence emerged to support probiotic supplementation for improving starch and fibre digestion, treating colic, or preventing salmonellosis—three of the most common reasons practitioners recommend them. Intriguingly, multistrain formulations did demonstrate improvements in aerobic fitness and stamina in exercising horses, suggesting a performance application worth investigating further, though results remain preliminary. A significant concern is that high doses of novel bacterial species occasionally exacerbated diarrhoea and caused adverse effects, whilst results for treating scouring in neonatal foals were conflicting. For practitioners, this review suggests considerable caution: most equine probiotics use human-derived bacterial species of uncertain benefit in horses, and evidence-based recommendations are limited primarily to potential performance enhancement in athletic animals at standard doses, with careful monitoring for adverse reactions.
Read the full abstract on PubMed
Practical Takeaways
- •Do not routinely recommend probiotic supplements to improve digestive efficiency or prevent common gastrointestinal conditions like colic or salmonellosis in horses
- •Exercise caution with high-dose novel probiotic products, as they may worsen diarrhea rather than improve it
- •Consider multistrain probiotic formulations for performance horses where improved stamina and aerobic fitness are goals, though evidence remains limited
Key Findings
- •No clear benefits for probiotic supplementation to improve starch and fiber digestion in horses
- •No evidence supporting probiotics for colic treatment or salmonellosis prevention
- •Conflicting results observed for management of scouring in neonatal foals
- •High doses of novel probiotic species may exacerbate diarrhea and cause adverse events
- •Multistrain probiotic formulations showed promise for improving aerobic fitness and stamina in exercising horses