Effects of oral versus parenteral cobalamin supplementation on methylmalonic acid and homocysteine concentrations in dogs with chronic enteropathies and low cobalamin concentrations.

The objective of this study was to compare the effects of parenteral (PE) versus oral (PO) cobalamin supplementation on serum methylmalonic acid (MMA) and homocysteine (HCY) concentrations in dogs with hypocobalaminaemia. Thirty-six dogs with serum cobalamin concentrations below 285ng/L (reference interval (RI): 244-959ng/L) were treated with PO (0.25-1.0mg daily) or PE cobalamin (0.25-1.2mg/injection) using a block-randomized schedule. Serum MMA and HCY concentrations were analysed at day 0, 28 and 90 after start of supplementation. There was no significant difference between the PO and PE group regarding serum MMA or HCY concentrations at any time point. Median (range, P comparing baseline and 28 days, P comparing 28days and 90 days) serum MMA concentrations (nmol/L; RI 415-1193) were 932 (566-2468) in the PO and 943 (508-1900) in the PE group at baseline, respectively, 705 (386-1465, P<0.0001) and 696 (377-932, P<0.0001) after 28 days, and 739 (450-1221, P=0.58) and 690 (349-1145, P=0.76) after 90 days. Serum HCY concentrations (median (range), P comparing baseline and 28 days, P comparing 28days and 90 days, µmol/L; RI 5.9-31.9) in the PO and PE groups were 12.2 (3.3-62.2) and 8.4 (3.7-34.8) at baseline, 12.5 (5.0-45.0, P=0.61) and 8.0 (3.8-18.3, P=0.28) after 28 days, and 17.7 (7.3-60.0 P=0.07) and 12.4 (6.3-33.1, P=0.0007) after 90 days, respectively. Oral and parenteral cobalamin supplementation had the same effect on serum MMA concentrations in this group of dogs.

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<285ng/L (reference interval 244-959ng/L) were enrolled. Dogs were randomised to treatment with either daily oral cobalamin tablets (0.25-1.0mg cyanocobalamin daily according to body weight) or parenteral cobalamin (0.4-1.2mg hydroxycobalamin according to body weight). Serum cobalamin concentrations were analysed 28±5days and 90±15days 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 28days 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 28days 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 28days and 90days (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.