Ultrasonographic evidence of colonic mesenteric vessels as an indicator of right dorsal displacement of the large colon in 13 horses.

The research study examined the usefulness of ultrasound in diagnosing a specific intestinal condition in horses known as right dorsal displacement of the large colon (RDDLC) prior to surgery.

Study Overview

• The study focused on identifying RDDLC in horses using ultrasound imaging. RDDLC is a serious condition that affects the large colon in horses, causing it to move to an abnormal position within the abdomen. This displacement often results in severe health issues necessitating surgical intervention.
• The researchers examined 13 horses via ultrasonography, with the evaluations carried out on the right side of the horse’s abdomen. Ultrasonographic examinations were performed using a 2-5 MHz broadband curvilinear sector scanning transducer after the hair in that region was wetted with alcohol for clearer imaging.

Procedure and Findings

• The procedure involved first identifying the caecal vessels (blood vessels supplying the caecum, a pouch-like structure part of the horse’s intestines) in the right flank of the horse, and tracking their direction towards the midsection.
• This was followed by scanning each space between the ribs (intercostal space), going from the back end to the front end of the horse. The scanning was done from back (dorsal) to front (ventral), looking for unusually-placed mesenteric vessels associated with the large colon. Mesenteric vessels are specific blood vessels that supply the intestines.
• Abnormal mesenteric vessels, distinct from the identified caecal vessels, were discovered in 13 out of 23 horses that had RDDLC as confirmed by exploratory laparotomy (surgical incision made to examine abdominal organs).

Study Conclusion

• The study concluded that the presence of mesenteric vessels in an abnormal location along the right flank of a horse, at least in two intercostal spaces and distinct from the caecal vessels, is closely tied to a surgical diagnosis of RDDLC in horses.
• This indicates that ultrasound imaging can be effectively used for pre-surgical identification of RDDLC, and could potentially assist in guiding surgical interventions for the condition in the future.