Comparison of efficacy of oral and parenteral cobalamin supplementation in normalising low cobalamin concentrations in dogs: A randomised controlled study

The aim of this study was to compare the efficacies of parenteral and oral cobalamin supplementation protocols in dogs with chronic enteropathies and low cobalamin concentrations. It was hypothesised that both treatments would increase serum cobalamin concentrations significantly. Fifty-three dogs with chronic enteropathies and serum cobalamin concentrations < 285 ng/L (reference interval 244-959 ng/L) were enrolled. Dogs were randomised to treatment with either daily oral cobalamin tablets (0.25-1.0 mg cyanocobalamin daily according to body weight) or parenteral cobalamin (0.4-1.2 mg hydroxycobalamin according to body weight). Serum cobalamin concentrations were analysed 28 ± 5 days and 90 ± 15 days after initiation of supplementation. After 28 days, all dogs had serum cobalamin concentrations within the reference interval or above. In the parenteral group (n = 26), median (range) cobalamin concentrations were 228 (150-285) ng/L at inclusion, 2107 (725-10,009) ng/L after 28 days and 877 (188-1267) ng/L after 90 days. In the oral group (n = 27), median (range) serum cobalamin concentrations were 245 (150-285) ng/L at inclusion, 975 (564-2385) ng/L after 28 days and 1244 (738-4999) ng/L after 90 days. In both groups, there were significant differences in serum cobalamin concentrations between baseline and 28 days, and between 28 days and 90 days (P < 0.001). In conclusion, both parenteral and oral cobalamin supplementation effectively increase serum cobalamin concentrations in dogs with chronic enteropathies and low cobalamin concentrations.