Effects of Bit Chewing on Right Upper Quadrant Intestinal Sound Frequency in Adult Horses

Many therapies have been proposed to prevent and treat postoperative ileus (POI) in horses, but to date none is considered fully effective. Various methods have been considered in the prevention of POI in humans too, and among these, gum chewing is gaining a role, reducing time from surgery to first fecal passage and hospitalization time. The aim of the present study is to produce a method to consistently induce horses at chewing without ingesting food and to evaluate its effects on gut sounds in healthy horses. Animals used in this study were 10 adult horses of both genders. A digital phonendoscope was positioned on the right upper flank. A first registration was started and lasted for five consecutive minutes. Then a snaffle bit with toggles was applied to the horse, and a second registration was obtained in the following 15 minutes. Recording sessions were cut into 5-minute subsessions and blindly assessed by two operators that calculated the number of borborygmi per minute in each session. Application of a bit produced consistent mastication and swallowing in all horses for a period of 20 minutes or more. There was a significantly different increase in short (<3 seconds) gut sounds in the first 5 minutes after application of the bit. In conclusion, mastication of a bit consistently caused an increase in gut sounds on the right upper quadrant. Bit chewing can be easily obtained in horses at rest, and further evaluation as an adjunctive element in the management of POI is warranted.