Clinical bronchography in the horse: development of a method using barium sulphate powder.

This study showcases a new method for conducting bronchography in horses while they are standing and not under anesthesia. The method involves the use of a finely powdered mixture of barium sulphate and methyl cellulose, which is insufflated in the trachea for quick visibility and clearance, proving safe and effective in examining bronchial conditions in horses.

Method Development

• The research revolves around developing a new method for bronchography in non-anesthetized, standing horses, a feat rarely achieved before.
• For this, a specially-prepared mixture containing 120 to 200 grams of finely powdered barium sulphate and 3 to 7 grams of powdered methyl cellulose was used; the mix was delivered into the already intubated trachea of the horse.
• The mixture was delivered using an ether vapouriser blown into by compressed air.
• Researchers applied pre-medication using atropine sulphate to the horses right before insufflation to limit bronchoconstriction early on.

Results of the Study

• The new method provided satisfactory bronchograms, with the contrast being visible up to the seventh and eighth bronchial divisions in 80 percent of the 26 tested horses.
• Results were poorer if there were any delays during the exposure taking process.
• The barium sulphate was entirely eliminated from the lung fields of the subjects rapidly, taking an average of just four hours.

Side Effects and Histological Findings

• The study found no significant clinical side effects associated with the application of this method in the participating horses.
• Lung histology of the animals, which were sequentially sacrificed over two weeks, showed minimal cellular responses.
• In a single clinical case involving chronic bronchitis, loss of parallelism in the bronchial walls along with moderate bronchial dilation between branches was confirmed.

Conclusion and Implications

• The value of bronchography as a diagnostic procedure in equine radiology is yet to be proven conclusively, but the study found that the powdered barium sulphate insufflation method holds promise.
• This method provides a safe and accurate way of investigating bronchial conditions in horses, thereby opening doors towards improved diagnostic procedures for equine respiratory disorders.