Histology of dogs without gastrointestinal symptoms and of dogs suffering from gastrointestinal diseases. Intestinal samples of dogs used as healthy controls (A: dog no. 8, bar: 200 μm; B: dog no. 8, bar: 50 μm) and of dogs with intestinal nematode infection (C: dog no. 20, bar: 200 μm; D: dog no. 20, bar: 50 μm) revealed comparable freshness to intestinal biopsy specimens. In dogs with intestinal nematode infection, mucosal inflammation was dominated by eosinophilic granulocytes in addition to increased amounts of lymphocytes, plasma cells, and neutrophils (D: dog no. 20, bar: 50 μm). Furthermore, parasitic structures resembling nematode larvae were occasionally present within inflammatory foci (E: dog no. 20, bar: 50 μm). In dogs with LPE, intestinal mucosa was infiltrated by lymphocytes and plasma cells (F: dog no. 9, bar: 100 μm).