Association between lactulose administration and hypercalcemia in dogs medically managed for hepatic encephalopathy.

Objectives: Identify if lactulose administration is associated with hypercalcemia in dogs medically managed for hepatic encephalopathy due to a portosystemic shunt and measure any magnitude in change of ionized calcium (iCa) or total calcium.

Animals: Seventeen client-owned dogs diagnosed with a portosystemic shunt and medically managed with lactulose.

Procedure: Total calcium and iCa were measured at Time point 1 (T1), before starting medical management; and Time point 2 (T2), the time of a reassessment after > 3 wk of lactulose administration.

Results: There were no statistically significant differences in iCa or total calcium between T1 and T2. Lactulose dose was positively correlated with change in iCa between T1 and T2.

Conclusion and clinical relevance: This study did not identify the development of hypercalcemia in a population of dogs treated with lactulose for the management of hepatic encephalopathy. A possible correlation was present between dose of lactulose and change in iCa, and this may represent a dose-dependent association.