Enteritis

Enteritis is the inflammation of the intestinal lining and is one of the leading causes of death in baby rabbits that have been weaned too early.

Why are baby rabbits prone to enteritis?
Rabbits have very few micro-organisms in the stomach and small intestine while they are suckling. An antimicrobial fatty acid (milk oil) is produced by an enzymatic reaction with the doe's milk in the suckling rabbit's stomach. This milk oil controls the gastrointestinal microbial contents of the baby rabbits and protects them from enteric infection. :86

Orphaned baby rabbits that are fed from milk of other species do not develop the above antimicrobial factor, and as a result, they can be more susceptible to bacterial infections during feeding. Cecotropes and probiotics can be helpful supplements during weaning to help colonize the intestinal tract with healthy bacteria and protozoa. :86