Free Faecal Water: Analysis of Horse Faecal Microbiota and the Impact of Faecal Microbial Transplantation on Symptom Severity

Abstract

Free faecal water (FFW) in equines results in pollution of the hindquarters and tail and can also involve clinical signs. Though the cause of FFW is unknown, it was hypothesized that it may involve the gut microbiota. This hypothesis was addressed as follows. First, the faecal prokaryotic community composition of horses suffering from FFW relative to healthy controls (n = 10) was compared. Second, FFW horses were treated with a standardised faecal microbiota transplantation (FMT) protocol (n = 10), followed by assessment of FFW symptom severity and faecal prokaryotic community composition over a follow-up period of 168 days. No significant differences were found in the faecal microbiota composition of FFW horses compared to healthy controls (p > 0.05). Relative to before FMT, FFW symptom severity decreased in affected horses 14 days after FMT (p = 0.02) and remained decreased for the remainder of the study (p < 0.02). However, individual animal responses to FMT varied. FMT had no effect on FFW horse faecal prokaryotic community composition in terms of alpha or beta diversity. Alpha diversity of the donor inocula used in the FMT was always lower than that of the faecal microbiota of the FFW treated horses (p < 0.001). In conclusion, whilst findings indicate FFW horses do not have an altered hindgut microbiota, some horses that received FMT had a temporary alleviation of FFW symptom severity without causing changes in the faecal microbiota. Future studies using controls are now needed to confirm the effectiveness of FMT to treat FFW.

Carbonate buffer mixture and fecal microbiota transplantation hold promising therapeutic effects on oligofructose-induced diarrhea in horses

“…Furthermore, additional studies have also indicated the ineffectiveness of FMT in horses for the treatment of diarrhea. One particular study found no impact of FMT in addressing free fecal water in horses, suggesting that gut microbiota alterations may not be a contributing factor to this condition ( 20 ). Another study revealed that FMT achieved only a 67% success rate in managing diarrhea in a small cohort of six horses ( 19 ).…”

Current Understanding of Equine Gut Dysbiosis and Microbiota Manipulation Techniques: Comparison with Current Knowledge in Other Species

“…However, no long-term evaluation was performed, and the recipient group was small and heterogenous (age differences, clinical signs and treatment) [ 106 ]. Laustsen et al treated ten horses suffering from Free Fecal Water syndrome (a condition characterized by the presence of water along with well-formed fecal balls) with FMT for five days [ 176 ]. No significant changes were found in the microbiota of the treated animals but, again, only 500 g of feces were used to prepare the FMT solution.…”

Equine Fecal Microbiota Transplantation: Possible Mechanisms and Future Perspectives

“…Also, there is no guarantee that FMT can treat all gastrointestinal disorders. A recent study documented a temporary effect worked when horses with Fecal Water Syndrome were treated with FMT [96]. However, it should be noticed that the main purpose of FMT is to restore a disrupted gut microbiota.…”