CHANGES IN THE INTESTINAL MUCOSAL CELL-POPULATIONS OF GERMAN-SHEPHERDDOGS FED DIETS CONTAINING DIFFERENT PROTEIN-SOURCES

Sixteen German Shepherd Dogs from 4 litters were IgA-deficient on the basis of at least 1 of 2 serum IgA determinations, and all had small i ntestinal bacterial overgrowth, as documented by quantitated small int estinal bacterial culture in another study. These dogs were fed 2 diet s that differed principally in their protein source (chicken vs beef, milk, and wheat). All dogs were fed each diet for 2 weeks be fore the study began. Next, all dogs were fed the chicken-based diet for 2 mont hs. Then, half the dogs (group 1) were randomly assigned to continue e ating the chicken-based diet, while the other half (group 2) ate a die t containing beef, milk, and wheat proteins. The small intestine was b iopsied at the beginning of the study and after dogs had eaten the ass igned diet for 2 and 4 months. At 2 months, group-2 dogs had more colo nic mucosal mast cells, but this difference did not persist at 4 month s. At the end of the study (ie, 4 months), although all dogs were clin ically normal, group-2 dogs had significantly (P = 0.010) decreased nu mbers of jejunal villus plasma cells. However, these histologic change s were not considered clinically important. There were no significant differences in blood eosinophil counts, serum trypsin-like immunoreact ivity, or cobalamin, folate, or IgA concentration. Clinical difference s were not detected between the 2 groups, before or after the study. C hanges were seen in serum IgM and IgG concentrations. Although results of this study suggest that dietary protein may influence intestinal m ucosal cell populations, there was no evidence that the protein source s in these 2 diets caused intestinal disease in these dogs under the c onditions of this study.