Horses with and without free faecal liquid

A common problem encountered in horse veterinary practice is the one of chronic loose or watery stools in otherwise healthy horses. Besides the worry that the horse may be in ill health, keeping these horses tail and stall clean is quite a chore. Other than getting the diet as fibrous as possible and removing alfalfa from the diet little was of much effect and sometimes that did not help a lot. So, I was glad to see this study though it did not find a specific cause or set of causes. Of interest is how similar the watery stools were to firm stools. Also of interest is the comment that the fecal matter itself seemed less capable of retaining water. Hopefully further research will further define the problems and lead us to more effective treatments.
DrO

Chemical composition and physical characteristics of faeces in horses with and without free faecal liquid – two case-control studies
BMC Vet Res. 2022 Jan 3;18(1):2. doi: 10.1186/s12917-021-03096-1.
Authors
K M Lindroth 1 , J Dicksved 2 , I Vervuert 3 , C E Müller 2
Affiliations

1 Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden. katrin.lindroth@slu.se.
2 Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden.
3 Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Faculty of Veterinary Medicine, University of Leipzig, D-04159, Leipzig, Germany.

PMID: 34980103
DOI: 10.1186/s12917-021-03096-1

Abstract

Background: Free faecal liquid (FFL) is a condition in horses characterised by two-phase (one solid and one liquid) separation of faeces. Causes of the condition are unknown, but disturbed hindgut fermentation has been suggested as it may alter biochemical composition and appearance of faeces in equines. However, information on faecal composition in horses with FFL is scarce. Faecal chemical composition (dry matter, osmolality, ash, macro minerals, short-chain fatty acids (SCFA) and pH) and physical characteristics (free liquid, sand, water holding capacity and particle size distribution) were compared in horses with (case) and without (control) FFL in two sub-studies. In sub-study I, faeces from 50 case-control horse pairs in Sweden and Norway were sampled in three sampling periods (SP1-SP3). In sub-study II, faeces from 32 case-control horse pairs in Germany were sampled on one occasion.

Results: In sub-study I, faecal concentration and proportion of lactic acid (of total short-chain fatty acids, SCFA) and water holding capacity was lower in case compared to control horses. Other variables (content of dry matter, ash, sodium, calcium, phosphorous, magnesium, sulphur, and concentrations of i-butyric, n-valeric and total SCFA, ammonia-N as proportion of total N, and pH) were similar in faeces from case and control horses. In sub-study II, all analysed variables were similar in faecal samples from case and control horses. Faecal particle size distribution was similar in case and control horses, but the proportion of larger particles (2 and 1 mm) were lower and proportion of smaller particles (< 1 mm) was higher in sub-study I compared to in sub-study II. Conclusions: To the authors' knowledge, this is the first study to investigate faecal chemical composition and physical characteristics in horses with FFL. Case and control horses had similar total SCFA, pH and osmolality, indicating that hindgut fermentation was similar. However, small differences in concentration and proportion (of total SCFA) of lactic acid and water holding capacity of faeces were shown and are of interest for further studies of horses with FFL. Keywords: Equine; Free faecal water; Lactic acid; Particle size; SCFA; Water absorptive capacity.