Ileal cannulation and associated complications in dogs

Accurate measurement of small intestinal digestibility is important in dogs because it allows the formulation of pet foods that provide optimal nutrition at minimal cost. Digestibility measured by comparing nutrient intake to fecal excretion in intact animals does not distinguish small intestinal digestion from large intestinal bacterial fermentation. Ileal cannulation allows small intestinal digestion to be measured alone by comparing nutrient intake with ileal excretion of chyme. Nevertheless, ileal cannulation and its associated complications are not well documented in dogs. We describe the implantation of a simple T-cannula in the ileum of nine dogs for an average duration of 26 weeks. Established cannulas were well tolerated, and one dog retained the cannula for 14 months. Nevertheless, ileal effluent proved extremely caustic, and the incidence of complications in the immediate postoperative period was high. Only one dog had an unremarkable postoperative course. Complications included abscessation and cannula extrusion, followed by severe excoriation and ulceration of the skin. This excoriation could be prevented only by immediate surgical closure of the fistula. Chronic ileal cannulation is therefore a viable technique in dogs, but careful monitoring of the cannula site is essential. Dogs should be subjected to this procedure only if adequate veterinary and nursing care is available. It is preferable to maintain a colony of long-term cannulated dogs rather than to implant cannulas as needed.