Changes of Enterocyte Morphology and Enterocyte: Goblet Cell Ratios in Dogs with Protein-Losing and Non-Protein-Losing Chronic Enteropathies

SIMPLE SUMMARY: Recent studies have emphasized the importance of intestinal mucosal architectural changes in chronic enteropathies such as celiac disease and chronic environmental enteropathies in human beings. This current study sought to examine changes in the morphology of the intestinal enterocytes and the proportion of mucus-producing cells (goblet cells) to enterocytes in the small and large intestines of dogs with chronic enteropathies (CE). Tissue samples from healthy dogs and dogs with CE with and without protein-losing enteropathy (PLE), were assessed. Healthy adult dogs presented with progressively shorter enterocytes from duodenum to jejunum to ileum, while juvenile dogs presented with increasing enterocyte height in the same direction. Dogs with CE had taller cells in the duodenum, while those with PLE had decreased duodenal enterocyte height compared to healthy dogs. The width of the intestinal cells was also reduced in CE dogs compared to healthy dogs. Additionally, the ratio of goblet cells to intestinal cells in CE was decreased in the colon when compared to healthy dogs. This study demonstrates that dogs with chronic enteropathies, similar to celiac disease in people, present with significant alterations in the size of the enterocytes and a reduced proportion of mucus-producing cells in the colon. ABSTRACT: This study aimed to assess the morphometry of enterocytes as well as the goblet cell-to-enterocyte ratio in different intestinal segments of dogs with chronic enteropathies (CE). Histopathological intestinal samples from 97 dogs were included in the study (19 healthy juveniles, 21 healthy adults, 24 dogs with protein-losing enteropathy (PLE), and 33 CE dogs without PLE). Healthy adult small intestinal enterocytes showed progressively reduced epithelial cell height in the aboral direction, while juvenile dogs showed progressively increased epithelial cell height in the aboral direction. CE dogs had increased epithelial cell height in the duodenum, while PLE dogs had decreased epithelial cell heights compared to healthy adult dogs. Both the CE and PLE dogs showed decreased enterocyte width in the duodenal segment, and the ileal and colonic enterocytes of CE dogs were narrower than those of healthy adult dogs. CE dogs had a lower goblet cell-to-enterocyte ratio in the colon segment compared to healthy dogs. This study provides valuable morphometric information on enterocytes during canine chronic enteropathies, highlighting significant morphological enterocyte alterations, particularly in the small intestine, as well as a reduced goblet cell-to-enterocyte ratio in the colon of CE cases compared to healthy adult dogs.