Effects of detomidine on equine oesophageal function as studied by contrast radiography.

The research explores how sedation with detomidine affects the function of a horse’s oesophagus, using contrast radiography for analysis. The study finds significant dose-dependent changes in oesophageal function, advising against the use of detomidine before radiographic examinations in horses.

Methodology

• Ten healthy adult thoroughbred horses were evaluated in the study.
• To assess the oesophagus function, the horses were administered barium swallows, which were studied using image intensifier technology.
• Initially, the oesophageal function was evaluated without any sedation.
• Subsequently, the horses were sedated with detomidine at doses of 10 and 20 micrograms per kilogram bodyweight.
• The study recorded the transit time of the contrast agent to the oesophageal hiatus and monitored each swallow for signs of oesophageal dysfunction.

Results

• Data analysis revealed significant dose-dependent increases in the transit time of the contrast agent (barium), retention of barium within the oesophagus’ longitudinal mucosal folds, and retrograde peristalsis and pooling of the contrast agent within the oesophagus at the thoracic inlet and at the end near the heart base.
• However, the level of gastrooesophageal reflux remained unaffected at both doses.
• The changes in oesophageal function caused by detomidine were similarity to those seen in horses suffering from a disease called grass sickness.

Conclusion

• The findings of the study indicate caution in interpreting studies involving swallowing in animals that have been administered detomidine before a radiographic examination, as it can significantly alter the oesophageal function.