A rabbit's digestive system is built to process a herbivorous, fiber-rich diet made up of grass, hay and vegetables. It's unique and highly specialized to extract the most nutrients possible from the plants it eats.
The journey, step by step
- Mouth and teeth. Rabbits have incisors that grow continuously throughout their lives, which lets them chew fibrous food. They chew from side to side, which makes it easier to grind up plant fiber.
- Esophagus. After chewing, food passes into the esophagus, a tube that carries it from the mouth to the stomach through peristaltic movements.
- Stomach. Rabbits have a monogastric stomach, meaning a single chamber. Here, gastric acids start digesting protein, but because food moves through the stomach quickly, most digestion happens further down, in the intestine.
- Small intestine. In the small intestine, food mixes with bile and pancreatic enzymes, and nutrients like protein, sugars and fats are digested there. Fiber, however, isn't broken down at this stage.
- Cecum. The cecum is the most important part of a rabbit's digestive system. It's a large fermentation chamber holding bacteria and other microorganisms that break down the plant fiber that wasn't digested earlier. The products of this fermentation are absorbed and used as energy.
- Cecotrophy. One unique feature of a rabbit's digestive system is the production of cecotropes: soft, nutrient-rich droppings that rabbits pass and then eat again. By eating these cecotropes, rabbits can digest a second time the nutrients that weren't absorbed the first time around.
- Colon and large intestine. This is where water is absorbed and the hard droppings form that the rabbit doesn't eat again. These droppings are passed as part of normal excretion.
This system lets them maximize nutrient absorption from a diet that is very low in calories and high in fiber, a crucial requirement for their survival.
