1. Dogs develop severe gastrointestinal symptoms in response to intraintestinal administration of staphylococcal enterotoxin. These symptoms are salivation, vomiting, and diarrhea.
2. Staphylococcal enterotoxin induces acute enteritis marked by edema, hyperemia, round cell infiltration, mucosal exudation, and destruction of intestinal villi.
3. Prolonged administration of enterotoxin into the lumen of the intestine produced thickening of the entire bowel wall, edema, dilatation of the lymphatics, and exaggeration of submucous lymphoid nodules. The hypertrophy of the lymphoid nodules is visible, in the gross, as enlarged longitudinal mucosal ridges. This abnormality is arranged in skip areas, not dissimilar to those observed in human regional enteritis.
4. Chronic enterotoxin enteritis is associated with mesenteric lymph node hypertrophy.
5. The intestinal mucosa shows minute ulcerations, loss of villi, submucous fibrosis, and evidence of chronic inflammation.