Cytokine mRNA expression in mucosal biopsies from German Shepherd dogs with small intestinal enteropathies

German shepherd dogs (GSD) are predisposed to enteropathies such as inflammatory bowel disease (IBD) and small intestinal bacterial overgrowth (SIBO). The present study examined the role of cytokines in the immunopathogenesis of both conditions. Duodenal mucosal biopsies were taken from GSDs with small intestinal enteropathies (group 1; N = 16) or control dogs (group 2, N 12). IL-2, IL-4, IL-5, IL-10, IL-12p40, IFN-gamma, TNF-alpha, and TGF-beta 1 mRNA expression was determined by semiquantitative reverse transcriptase polymerase chain reaction. IL-2, IL-5, IL-12p40, TNF-alpha, and TGF-beta(1) mRNA expression in group 1 dogs was significantly greater than in group 2 dogs (all P < 0.01), but there were no significant differences between dogs with IBD or SIBO. Further, antibiotic treatment in five dogs with SIBO, resulted in reduced TNF-alpha and TGF-beta(1) mRNA expression (P < 0.05). Such alterations in cytokine mRNA expression suggest heightened immune responses within the duodenal mucosa in GSDs with either SIBO or IBD.