Rabbits are true herbivores. They rely on grasses and greens to keep their digestive health accommodated. An indoor rabbit needs good quality grass/hay and this should be the main stay of their diet. They need the long fibers of the grasses to keep their digestive system going and to keep their teeth worn down. They also need a variety of fresh vegetables such as lettuce, parsley, cabbage, kale, bell pepper and carrots with the top on. Dark leafy greens can consist of anything that grows in the garden. Anything that is safe enough for us to eat is safe enough for them. They also love herbs such as parsley or cilantro. A 5 pound rabbit should eat a full 4 cups of fresh vegetable a day.
The hay can be spread out throughout their enclosures so that they can nibble whenever they get the urge. You can use hay feeding racks in their litter box or you can put it in toys.
Pellets provide a nice source of trace minerals and nutrients but are high in carbohydrates, protein and fat. Try to limit the number of pellets to 1/8 cup per rabbit per day. If given a free choice, rabbits will eat pellets over fresh vegetables. A good quality pellet never comes with seeds, corn, nuts or dried fruit. These are not good for rabbits.
They need to avoid the starchy vegetables like corn, beans, and sometimes even carrots in large quantities. All dried fruits should be avoided. Raisins, for example, can give rabbits cavities. Fruits are fine in very small amounts as treats.
You should always provide fresh water. You can use a nice heavy crock that they can’t tip over or a water bottle. After eating hay they’ll need the water to help lubricate the intestines.
Rabbits do produce a large amount of feces. Small, dry round feces is normal. They have been known to produce what is called “night feces” or Cecotropes. They are soft and mucous-like. The rabbit recycles this stool, meaning they eat these feces to get some of the nice vitamins from fermentation in their gut. They recycle it to complete their diet.