Evaluation of gastrointestinal permeability and mucosal absorptive capacity in dogs with chronic enteropathy

OBJECTIVE: To assess intestinal mucosal function by measuring permeability and absorptive capacity in dogs with chronic enteropathy (CE) before and after treatment and to determine whether those variables were correlated with clinical disease activity or histologic scoring of intestinal biopsy specimens. ANIMALS: 29 dogs with CE. PROCEDURE: Dogs were designated as having dietresponsive CE or CE requiring glucorticoid treatment. Severity of clinical signs was assessed by calculating the canine inflammatory bowel disease activity index (CIBDAI). Histologic severity of intestinal infiltration was assessed before and after 4 weeks of treatment in the diet-responsive group and before and after 10 weeks of treatment in the glucocorticoid group. Gastrointestinal permeability and mucosal absorptive capacity were assessed by use of intragastric administration of a solution containing lactulose, rhamnose, xylose, 3-O-methylglucose, and sucrose. Urine was collected 6 hours after administration of the sugar solution to determine urinary lactulose-to-rhamnose (L:R), xylose-to-methylglucose (X:M), and sucrose-to-methylglucose (S:M) ratios. RESULTS: Median CIBDAI scores decreased significantly in both groups of dogs after treatment. However, the median histologic grade of intestinal biopsy specimens did not change with treatment in either group. There were no significant differences in L:R, X:M, or S:M ratios after treatment in either group and no significant correlations between L:R, X:M, or S:M ratios and CIBDAI or histologic scores. CONCLUSIONS AND CLINICAL RELEVANCE: Results of tests for intestinal permeability and mucosal absorptive capacity were not useful indicators of clinical disease activity as assessed by the CIBDAI or the sever ity of infiltration as indicated by histologic evaluation.