Retrospective study of canine insulinomas: eight cases (2005-2008)

This retrospective study examined 8 cases of pathologically diagnosed insulinoma. Surgical intervention was performed in all cases, once insulinoma was suspected based on unique clinical signs, hypoglycemia, and/or findings on ultrasonography. At the same time, insulin and glucose concentrations were measured before surgery for clinical diagnosis. Although all cases displayed typical clinical signs and hypoglycemia, insulin concentrations varied with 3 of 8 cases showing levels within the reference interval. In addition, to confirm the reliability of measured values, we submitted serum samples from 4 cases to two commercial veterinary laboratories. Results differed considerably between laboratories, with no apparent correlations between the two. In Laboratory A, 3 of 4 cases were above the reference interval, and 1 case was in the middle of the reference interval. Conversely, in Laboratory B, 3 of 4 cases were above the reference interval, and 1 case was below the reference interval. Split decisions regarding the diagnosis of insulinoma were seen for 2 of the 4 cases.