Chapter 27 Diseases of the Digestive System
The digestive system of the bird is different from that of mammals. Birds have no teeth for cutting and grinding food. The esophagus, found on the right side of the neck in birds, contains a dilated portion called the crop used for food storage, allowing the bird to eat fast and travel. From the crop the food passes into the proventriculus (the glandular stomach), the ventriculus (the gizzard or grinding stomach), and then into the small intestine. After traveling through the small intestine, large intestine, and colon, the feces pass into the cloaca. Because the renal and reproductive tracts also empty into the cloaca, feces are excreted mixed with urine and urates. Disturbances of the digestive system are among the most common problems of captive birds.
Crop Stasis
Primary causes of crop stasis are:
Crop Burns

Figure 27-1 Crop burn with necrosis in a young hand-fed bird.
(From Altman RB, Clubb SL, Dorrestein GM, Quesenberry KE: Avian medicine and surgery, Philadelphia, 1997, WB Saunders, by permission.)
Beak Deformities

Figure 27-2 Lateral deviation of the maxilla in a macaw.
(From Altman RB, Clubb SL, Dorrestein GM, Quesenberry KE: Avian medicine and surgery, Philadelphia, 1997, WB Saunders, by permission.)
TREATMENT
Treatment will depend on the cause of the malformation.