2016 ACVIM Forum Research Abstract Program

The assay evaluated here was shown to be linear, precise, accurate, and reproducible. Dogs with chronic enteropathy had significantly lower serum citrulline concentrations than healthy dogs. Further studies are warranted to assess the clinical utility of the serum citrulline as a biomarker for enterocyte function in dogs. Dogs with symptoms of CE and a serum cbl below 285 ng/L (reference interval: 244-959 ng/L) were included from Evidensia Specialist Animal Hospital, Helsingborg, Sweden, Helsinki University Hospital, Finland, and from two other Swedish Veterinary Clinics. Dogs were randomized to treatment with either daily PO cbl tablets during the whole study period (cyanocobalamin (Behepan) 1 mg/tablet; dogs up to 10 kg received ¼ tablet, dogs 10 to 20 kg ½ tablet and dogs ≥ 20 kg 1 tablet/day) or PE cbl according to a protocol currently suggested by a diagnostic laboratory (http://vetmed.tamu.edu/gilab/research/cobalamin-information#dosing). A block-randomized schedule was performed by an external statistician prior to the start of the study in March 2014. The study was approved by the Swedish Board of Agriculture and the Viikki Campus Research Ethics Committee, Finland. Serum cbl for follow-up was analyzed 28 AE 5 days and 90 AE 15 days after initiation of supplementation using an automated chemiluminescence immunoassay (Immulite 2000, Siemens Healthcare Diagnostics). 41 dogs of 22 breeds were included with a median age of 6.2 (range 1.7-13.1) All of the dogs had symptoms of CE. Concurrent medical treatment and diet was given based on clinical judgement. Intestinal biopsies from the small and large intestine confirming chronic inflammation were available from 25/41 dogs. There was no statistically significant difference in serum cbl concentrations at baseline between the two groups (P = 0.25, Mann Whitney test). Serum cbl increased in all dogs after supplementation. In the group receiving PO supplementation, median serum cbl concentrations was 245 ng/l (150-285) at inclusion (n = 22), 970 ng/L (564-2026) after 28 days (n = 22), and 1334 ng/L (768-3921) after 3 months (n = 20). The difference between baseline and 28 days was statistically significant (P < 0.0001; Wilcoxon matched-pairs signed rank test) as well as the difference between 28 days and 3 months (<0.006; Wilcoxon matched-pairs signed rank test). In the group receiving PE cbl, mean cbl concentration was 221 AE 43 ng/L at inclusion (n = 19), 1686 AE 757 ng/L after 28 days (n = 19), and 803 AE 275 ng/L (n = 13) after 3 months. The difference between baseline and 28 days was statistically significant (P < 0.0001; paired t-test) as well as the difference between 28 days and 3 months (P = 0.0003, paired t-test). Comparing the increase in serum cbl concentrations at 28 days to baseline, the increase was significantly higher in the PE group than the PO group (mean increase 1465 AE 745 ng/L and 888 AE 449 ng/L, respectively, P = 0.004, unpaired t-test). However, after 3 months, the median (range) increase in serum cbl concentrations compared to baseline group were significantly higher in the PO than the PE group (970 ng/L (538-3663) and 608 ng/L (38-997), respectively, p = 0.0001, Mann Whitney test).