Digestive system

Rabbits are true herbivores and are classified as hindgut fermenters. Their gastrointestinal tract is relatively long, and its contents can make up 10 to 20 percent of their body weight.

Stomach
A rabbit's stomach comprises approximately 15% of total gastrointestinal volume. It has a well-developed cardiac sphincter that prevents vomiting.

The stomach usually contains hair, food, and fluid even after 24 hours of fasting or anorexia. Gastric transit time is approximately 3 to 6 hours.

How acidic is a rabbit's stomach?
A rabbit's stomach is extremely acidic with a pH of 1 to 2 and effectively kills bacteria and other microorganisms so that the stomach and small intestine are essentially sterile. The gastric pH may rise to 3.0 following the ingestion of cecotrophs.

In pre-weaned juvenile rabbits, the stomach's pH is higher at pH 5.0 to 6.5; after weaning, it drops to pH 2 to 3. Consequently, weanling rabbits are more prone to diarrhea because the stomach pH is not low enough to kill ingested bacteria.

Small intestine
The small intestine of the rabbit is the primary site of absorption of nutrients such as amino acids, lips, monosaccharides, and electrolytes.