Histological and Ultrastructural Findings in Commercial Bred Rabbits Exhibiting Severe Diarrhea

Abstract

The objective of this study was to describe histological and ultrastructural findings in the intestine of 8 rabbits  exhibiting severe diarrhea, a problem which occasionally severely effects commerceila rabbit breading  operations. Microscopic lesions from the small and large intestines were very similar to those described in  the mucoid enteritis complex. Histological lesions included mucoid neutrophilic or lymphocytic-plasmacytic  enteritis with atropy and fusion of the villi, hyperplasia of the goblet cells and submucosal and serosal  edema in the small intestine. Escherichia coli was isolated from 3 animals. The ultrastructural study  revealed in addition to hyperplasia of goblet cells, loss of microvilli in the small intestine. Furthermore  pseudonuclear inclusions surrounded by true nuclear membrane and free intranuclear and intracytoplasmic  virus-like particles were observed in all rabbits. It was concluded that the diarrhea had a multi-factorial etiology,  probably due to change in feed, bacterial proliferation and bacterial coinfection with enteric virus.