Free Faecal Water in Horses: Analysis of faecal microbiota and the impact of faecal microbial transplantation on symptom severity

  • Louise Laustsen (Creator)
  • Joan Edwards (Creator)
  • Gerben Hermes (Creator)
  • Nanna Lúthersson (Creator)
  • David A. van Doorn (Creator)
  • Supattra Okrathok (Creator)
  • Theresa J. Kujawa (Creator)
  • Hauke Smidt (Creator)



Faecal Microbiota Transplantation (FMT) has been used in veterinary practice for decades, but no peer-reviewed study of its efficacy for equines is available. This is despite reports of its beneficial impact on several different gut-related conditions in horses. Therefore, a clinical field study was conducted where a standardized FMT protocol was administered to a cohort of horses all suffering from the same clinical symptoms, namely Free Faecal Water (FFW). FFW (also known as Faecal Water Syndrome) results in pollution of the hindquarters and tail and, in most cases, only subtle changes in the general health of the affected animal. It was hypothesised that horses suffering from FFW have an apter in their hindgut microbiota, which can be treated by FMT.In this study, no significant differences were found in terms of the alpha or beta diversity of the faecal microbiota of FFW horses (n=10) when compared to healthy controls (n=10) at the start of the study (i.e. prior to the FFW horses undergoing FMT). However, FMT significantly decreased FFW symptom severity 14 days after transplantation, and this decrease remained significant for the remainder of the 168 day monitoring period. As such, FMT should be considered as a supplementary treatment to alleviate symptom severity in horses suffering from FFW. However, due to the observed variation in individual responses to the FMT, additional studies are needed to develop an optimal FMT protocol and/or a means to identify which FFW patients are likely to benefit most from this treatment.
Date made available26 Jun 2020
PublisherWageningen University


  • metagenome
  • Free Faecal Water
  • horses
  • faecal microbial transplantation

Accession numbers

  • PRJEB35172
  • ERP118187

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