Salmonella enteritis, ileum, calf

Photomicrograph of the ileum of a 3-week-old calf with severe, acute, ulcerative, and fibrinonecrotic enteritis due to salmonellosis. The ulceration (complete loss of mucosa) is covered by numerous neutrophils, fibrin, and necrotic debris. Note the junction (indicated by arrows) between the fibrinonecrotic membrane and the underlying submucosa. The submucosa contains prominent vessels, mixed mononuclear inflammatory cells, and Peyer’s patches. Scale bar = 100 mcm.