Intestinal cannulation: Model for study of the midgut of the pig

Purpose: To develop a pig model that would enable repeated biopsy specimen collection and endoscopic monitoring of the gut. This would increase precis ion of the experiment and reduce the number of experimental animals require d. Methods: Six 16-week-old Yorkshire pigs underwent surgery, and a cannula wa s inserted in the cecum, Two pigs served as non-operated controls. The heal th status of the animals was monitored by clinical, hematologic, and bioche mical examinations and by studies of gut motility and microbial flora. The experimental period lasted for eight weeks and approximately 45 biopsy spec imens were obtained from each animal. Results: Repeated endoscopy was performed and biopsy specimens were taken. Adverse effects on the animal's health were not apparent, and differences w ere not evident in transit time of digesta or in diversity of the gut micro bial flora. After surgery there was a transient increase in the concentrati ons of haptoglobin, serum amyloid A, and plasma cortisol, and in body tempe rature and white blood cell count. Conclusions: It is possible to use an intestinal cannula in the cecum both for endoscopy and biopsy specimen collection. The procedures did not influe nce health status of the pigs, nor alter gut function. The method will be u seful in experimental infection studies as well as in other physiologic inv estigations.