The digestive system of Ratites (ostrich, emu, casowary, kiwi, rhea) is very similar to those of the birds, but with significant specific qualitis. The tongue (lingua) is small, triangular or U-shaped ; palate (palatum) has a hard (bony) and soft (connective tissue and mucose membrane) parts ; the initial portion of the ooesophagus is very wide, there is no significant ingluvies and at the level of the six vertebral rib dilates and opens into the proventriculus. Proventriculus (pars glandularis) on the greater curvature dorsally and caudally has a glandular area (regio glandularis) and the ventriculus (pars muscularis) is thick-walled structure with left and right tendinous centres. The mucous membrane of the proventriculus and ventriculus is enveloped by koilin. The duodenum forms a narrow, extended loop with ascending and descending limbs. The jejunum forms the extensive coils which occupy the cranioventral part of the abdomen. The ileum is the longest part of the small intestine, extending to the caeca and forms extensive coils that occupy left and right caudoventral part of the abdomen and pelvis. The both of the caeca have a sacculated appearance due to the presence of an internal spiral fold which enlarges its surface area. The colon is about 8 m long and three fairly distinc region can be identified: caudal terminal part, proximal narrowed part and distal dilatation of terminal colon. The left lobe of the liver (hepar) is divided into three lobes, while the right lobe is larger and undivided. There is no gall bladder. The pancreas lies in the mesoduodenum between two limbs of the duodenum, and the pancreatic duct opens opens into the ascending limb of the duodenum.

Veterinary medicine