Incidence of postoperative complications and outcome of 48 dogs undergoing surgical management of insulinoma

BACKGROUND: Information regarding outcome of dogs undergoing surgical management for insulinoma is based on studies of a small number of dogs. OBJECTIVES: To report the outcomes of dogs undergoing surgery as treatment for insulinoma, the prevalence of postoperative diabetes mellitus (DM) in this group and to determine if development of DM can be predicted. ANIMALS: Forty-eight client-owned dogs, with a histopathological diagnosis of insulinoma, from three European referral hospitals. METHODS: Retrospective observational study. Dogs were identified from a search of electronic hospital records. Cox's regression was used to determine factors associated with postoperative survival and relapse, and logistic regression was used to determine factors associated with the development of DM. RESULTS: Median survival time (MST) was 372 days (range 1-1680 days), with dogs with stage I disease having the longest survival time. Stage I dogs had MST of 652 days (range 2-1680 days), whereas dogs with either stage II or III disease had MST of 320 days (range 1-1260 days; P = 0.045). Postoperative hyperglycemia was identified in 33% (16/48) of the dogs, of which 9 (19% of the total population) developed persistent DM. No factors that could be used as predictors for development of DM were identified. CONCLUSIONS AND CLINICAL IMPORTANCE: Stage of disease and postoperative hypoglycemia were associated with greater odds of relapse and decreased survival time; these could be used when discussing prognosis. In this study, postoperative DM developed more commonly than previously reported, but no factors were identified that might be useful predictors.