[Preliminary results using a combined xylose absorption/hydrogen exhalation test in horses].

The research article investigates a new combined approach of xylose absorption and hydrogen exhalation to diagnose gastrointestinal disorders in horses, particularly those suffering from symptoms like chronic weight loss or diarrhea. The test is assessed in a group of normal horses and others with clinical signs, producing promising results as a potential tool for earlier and more accurate diagnosis.

Study Design

• The study was conducted on a sample of thirteen horses, comprising of four healthy animals and nine patients exhibiting chronic diarrhea or unexplained weight loss.
• For each horse, comprehensive clinical examinations were conducted. These included hematological and serum biochemical tests, bacterial and parasitic analysis of feces, serum electrophoresis, and abdominocentesis. Six of the clinical patients underwent gastroscopy and rectal biopsies were obtained from four of them.
• Two of the clinical patient horses were put to sleep within a duration of four weeks following the evaluative tests. Post-mortem examination in one of these confirmed a diagnosis of chronic granulomatous enteritis while the cause of weight loss in the other remained unidentified.
• In the other case studies, potential causes such as management practices, parasitic infections, chronic diseases of liver, kidneys and the heart were ruled out.

Testing Procedure

• The xylose absorption and hydrogen exhalation test involved subjecting the horses to an overnight fast. The following morning, a 10% solution of xylose was administered via a stomach tube at the rate of 0.5/kg/body weight.
• Blood samples were collected every thirty minutes over a period of four hours, to monitor plasma xylose levels. Breath samples were concurrently collected at the same frequency over a duration of eight hours.

Findings

• With the exception of one horse suffering from granulomatous enteritis, the diseased horses revealed minor deviations in peak plasma xylose concentration or the time taken to reach peak levels.
• None of the healthy horses displayed any increase in breath hydrogen after the xylose treatment. In contrast, five of the unwell horses showed increased breath hydrogen levels.
• Furthermore, the clinical case horses indicated higher fasting breath hydrogen levels (ranging from 7.5 to 61.5 ppm) compared to the healthy horses (having a range of 0-5 ppm).

Conclusion

• The study concludes that intestinal microbial composition changes, reflected in higher hydrogen production, might strongly impact, and possibly cause, gastrointestinal disorders.
• The combined test of xylose absorption and breath hydrogen exhalation could be a promising diagnostic tool for such conditions in horses, requiring further investigation.