Effects of 6 Weeks of Parenteral Cobalamin Supplementation on Clinical and Biochemical Variables in Cats with Gastrointestinal Disease

Abstract

Background: Effects and duration of commonly used protocols for cobalamin (Cbl) supplementation on cellular Cbl deficiency have not been determined in hypocobalaminemic cats.

Hypothesis/objectives: To evaluate effect of Cbl supplementation on clinical signs, serum and urine methylmalonic acid (MMA) concentrations over 16 weeks.

Animals: Twenty client-owned hypocobalaminemic cats with enteropathy.

Methods: Prospective study. Serum Cbl and serum and urine MMA concentrations were determined prospectively in cats at enrollment (t0), immediately before (t6), and 4 (t10) and 10 weeks (t16) after 6th Cbl injection (250 μg, IM q 7 days). Clinical signs severity (activity, appetite, vomiting, diarrhea, body weight) graded at each time point and expressed as clinical disease activity score.

Results: Clinical disease activity score decreased during supplementation and increased after treatment discontinuation. Median serum Cbl concentration increased significantly from t0 (111 pmol/L, range 111-212) to t6 (2,332.5 pmol/L, range 123-22,730) (P < 0.01). Values at t10 were 610.5 pmol/L (range, 111-2,527) and 180.5 pmol/L (range, 111-2,262) at t16 (P < 0.01). Median baseline serum MMA concentration (372 μmol/L, range 0.39-147,000) decreased significantly to 1.62 μmol/L (range, 0.18-806) at t6 (P < 0.01) and gradually increased to 5.34 μmol/L (range, 0.13-1,730) at t10 and 189 μmol/L (range, 0.4-983) at t16. Similar, nonsignificant, pattern observed for urine MMA concentration. Serum and urine MMA concentrations had not normalized in 12 and 6 cats, respectively, at t6.

Conclusion and clinical importance: The Cbl supplementation protocol used here did not lead to complete normalization of cellular Cbl deficiency in all examined cats, and biochemical improvements were transient.

Keywords: Biochemical; Cellular deficiency; Feline; Vitamin B12.

Figure 1

Combined box and scatter plot for serum Cbl concentration on a log‐scale. By the Tukey method, boxes represent median and IQR and whiskers outliers (values up to 75th percentile + 1.5 IQR). The reference range for serum Cbl concentration is indicated as a transparent blue area with an upper and lower horizontal gray line. P values obtained by applying a Friedman test followed by a Nemenyi post hoc test. Please note that plotted points can be indistinguishable due to individual values that are close or identical.

Figure 2

Combined box and scatter plot for serum MMA concentration on a log‐scale. By the Tukey method, boxes represent median and IQR and whiskers outliers (values up to 75th percentile + 1.5 IQR). The reference range for serum MMA concentration is indicated as a transparent blue area with an upper and lower horizontal gray line. P values obtained by applying a Friedman test followed by a Nemenyi post hoc test. Please note that plotted points can be indistinguishable due to individual values that are close or identical.

Figure 3

Combined box and scatter plot for urine MMA concentration on a log‐scale. By the Tukey method, boxes represent median and IQR and whiskers outliers (values up to 75th percentile + 1.5 IQR). Triangles representing outliers (values greater than 75th percentile + 1.5 IQR). The reference range for urine MMA concentration is indicated as a transparent blue area with an upper and lower horizontal gray line. P values obtained by applying a Friedman test followed by a Nemenyi post hoc test. Please note that plotted points can be indistinguishable due to individual values that are close or identical.

Figure 4

Combined box and scatter plot for the clinical disease activity score (y‐axis) versus the time of measurement (x‐axis). By the Tukey method, boxes represent median and IQR, whiskers outliers (values up to 75th percentile + 1.5 IQR). Triangles representing outliers (values greater than 75th percentile + 1.5 IQR). The dotted line represents the trend over time (derived from a second‐order polynomial regression). Please note that plotted points can be indistinguishable due to individual values that are close or identical.