<h2>Summary</h2> The whole pancreas in seventeen dogs and the uncinate process in twenty-seven dogs were subjected to one to five hours of ischemia. The adequacy of the ischemia was tested with intravenous methylene blue dye injections. Selected dogs were given intravenous glucose tolerance tests and all underwent intravenous tolbutamide tolerance tests. In all dogs, daily blood glucose, amylase, and insulin levels were obtained. The results showed that the canine pancreas is tolerant to one hour of normothermic ischemia, but not to two or more hours.