Normal motility of the cecum and right ventral colon in ponies.

To study the normal motility of the cecum and right ventral colon (RVC) in 3 mature Shetland ponies, a 6-part, indwelling, intraluminal catheter system was used to measure intraluminal pressure changes. Three catheters were placed in the cecum at 10, 25, and 40 cm from the cecocolic orifice, and 3 catheters were placed in the RVC at 10, 20, and 30 cm from the cecocolic orifice. Recordings were made during the interdigestive period beginning 2 weeks after surgical operation was done. Frequent, low-amplitude peaks (0.35 +/- 0.13 coordinated peaks/min) were seen involving the cecal body and caudal cecal base, which represented a haustra-to-haustra mixing pattern. Coordinated pressure peaks originated in the cecal body and progressed to the cranial cecal base (0.07 +/- 0.01/min) or originated in the cranial cecal base and progressed to the cecal body (0.07 +/- 0.04/min). Associated with a loud rush of ingesta heard on transabdominal auscultation and progression of liquid ingesta confirmed with barium contrast radiography, there was a series of coordinated, progressive pressure peaks which originated in the cecal body, sequentially involved the cecal base, traversed the cecocolic orifice, and extended into the RVC (0.36 +/- 0.05/min). It seemed that a pacemaker region existed in the cecal body and initiated the important aborally propagated progressive pattern responsible for the transit of ingesta from the cecum to the RVC. A separate mechanism for the transit of gas was not identified. In the RVC, infrequent, nondirectional, low-amplitude segmental pressure peaks (0.12 +/- 0.06/min), and aborally progressive coordinated pressure peaks originating at the beginning of the RVC (0.09 +/- 0.02/min), occurred.(ABSTRACT TRUNCATED AT 250 WORDS)