Identification and quantification of amines in the equine caecum.

This study explores compounds known as amines present in horses’ digestive system and their potential as contributing factors to acute laminitis. The researchers found that the concentration of certain amines exhibited changes based upon whether the horses were fed grass or hay, which may have implications for their circulatory and digestive health.

Research Objectives and Methodology

• This research intended to shed light on the connection between horse hindgut fermentation and acute laminitis – a painful and damaging equine foot condition. The hypothesis was that certain compounds (amines) produced in the hindgut during fermentation might affect blood flow to the horse’s digit (hoof).
• To identify these amine compounds, the researchers collected and analysed samples from the equine caecum and colon, which are key sections of the horse’s hindgut.
• In order to compare the concentration of these amines, the researchers fed the horses with two different diets – grass and hay.
• Fifteen specific amines were identified in the hindgut content whose concentrations exceeded 1 micromolar (a unit of concentration used in biochemistry).

Key Findings

• Results suggested a difference in the concentration of certain amines – phenylethylamine, isoamylamine, cadaverine, diaminoheptane and spermidine, based on the type of diet the horses consumed.
• Horses that fed on spring/summer grass had significantly higher concentrations of these amines in the caecum, as opposed to those on winter grass or hay.

Implications of the Findings

• The discovery of numerous amines in the equine hindgut suggests that these compounds may have a role in equine health and disease, particularly in relation to acute laminitis.
• Some of these amines might cause peripheral vasoconstriction (narrowing of blood vessels) if released into the bloodstream from the digestive tract. This could potentially disrupt the blood supply to the horse’s hoof, contributing to the onset of laminitis.
• The diet-related difference in amine concentrations raises the possibility that dietary management could be a strategy for preventing or managing acute laminitis in horses.