Free Faecal Water: What do we know and can equine faecal microbiota transplantation be used to manage this issue?

Free Faecal Water (FFW) is a condition recognised in horses. Horses with this condition defaecate normal faeces but before, after, or during defaecation (or sometimes even independently of defaecation) faecal water runs out of the anus (Kienzle et al. 2016). This condition is also often referred to as Faecal Water Syndrome or Free Faecal Liquid. Cases are normally isolated, with only one horse from a group or stable yard being affected. In general, horses often seem to be in good general health and do not appear to be affected negatively by the condition. However, FFW can be a real management issue to the owner who is involved in the daily care of the horse. For example, daily cleaning of the tail and legs of the horse may be required depending on frequency and amount of the faecal water produced. In some cases, the faecal water can cause skin irritation and skin lesions, subsequently affecting the horse’s welfare. FFW is recognized in horses of all breeds, including warm bloods and painted horses. No official information is available on prevalence of FFW, but the condition is seen frequently by equine veterinarians in Western Europe. Unfortunately, very little information on FFW is published (Ertelt and Gehlen 2015; Kienzle et al. 2016; Valle et al. 2013). Many different causes have been implicated in the development of FFW (see below), and several treatment options for FFW have been suggested or applied by equine practitioners. The limited published information on FFW prevents evidence-based conclusions with respect to its aetiology and the objective evaluation of treatment. This paper provides an overview of the current state of knowledge regarding the aetiology and potential management and treatment options associated with FFW. This paper was written as a starting point for a multidisciplinary discussion at the 9th European Equine Health & Nutrition Congress. The paper includes empirical information from the authors in terms of dealing with FFW cases, as well as some preliminary results of their clinical studies.