Lymphocytic-plasmacytic enteritis associated with bacterial overgrowth in a dog

Lymphocytic-plasmacytic enteritis, associated with small intestinal bacterial overgrowth, was diagnosed in a 3.5-year-old German Shepherd Dog with chronic intermittent diarrhea, using bacteriologic culture of duodenal juice and histologic examination of jejunal biopsy specimens. Oral administration of oxytetracycline alone resulted in clinical improvement and a marked decrease in the jejunal mononuclear cell infiltrate. Additional treatment with prednisolone administered orally resulted in almost complete clinical and histologic recovery. This case illustrates that small intestinal bacterial overgrowth may have to be considered as an underlying cause of lymphocytic-plasmacytic enteritis in the dog and that antibiotic treatment may be necessary to attain remission.