Rabbits are obligate herbivores. Their unique digestive system functions as a hindgut fermenter, specially adapted to process large volumes of high-fiber forage. This specialized anatomy, featuring an enlarged cecum, makes a high-fiber diet the single most important factor for a rabbit’s overall health and long lifespan. Without the correct dietary structure, rabbits are prone to serious dental and gastrointestinal problems, most notably gastrointestinal stasis. A proper diet ensures continuous gut movement and appropriate wear on their continuously growing teeth.
The Foundation of the Rabbit Diet Fiber
Hay must constitute 80% to 90% of a rabbit’s daily intake. This continuous supply of fiber is essential for dental abrasion and gut motility.
A rabbit’s teeth are open-rooted, meaning they grow throughout the animal’s life, up to 2 millimeters per week. Chewing on long-strand, coarse fiber wears down the molars evenly, preventing the formation of sharp enamel points, or spurs, that can cause painful oral lesions. Indigestible fiber particles stimulate the muscular contractions that keep the digestive tract moving, preventing the dehydration of gut contents and the potentially life-threatening condition of gut stasis. Rabbits should have unrestricted access to hay, offered in a volume roughly equal to their body size each day.
Grass hays (Timothy, Orchard Grass, Oat Hay) are recommended for adult rabbits due to their high fiber and lower protein and calcium content. Timothy hay is a popular choice for mature rabbits. Alfalfa hay is significantly higher in protein and calcium, making it appropriate only for young rabbits under seven months, or pregnant and nursing does. For adults, high calcium in Alfalfa can contribute to the formation of bladder stones.
Fresh Foods Essential Greens and Vegetables
Fresh produce supplies necessary hydration, vitamins, and minerals that hay alone may not provide. Leafy greens should form the bulk of this component, recommended at about 1 cup of packed greens per 2 pounds of the rabbit’s body weight daily. The ideal mix includes two to three types of greens for a balanced nutrient profile.
Good daily options include:
- Romaine, green leaf, and red leaf lettuces.
- Parsley.
- Cilantro.
- Dill.
- Basil.
Greens should be washed thoroughly before serving. Avoid Iceberg lettuce entirely, as it offers virtually no nutritional value and its high water content can cause digestive upset.
Introduce any new vegetable or green slowly, offering one new type at a time over several days. This allows the sensitive digestive system to adjust and helps the owner observe for signs of softer stools. Vegetables like spinach and kale should be fed only in moderation or rotation due to their higher calcium or oxalic acid content.
Measured Supplements and Treats
Pellets are a concentrated source of nutrition, designed to supplement hay and greens, not replace them. They provide vitamins and minerals that can be difficult to ensure through forage alone. High-quality pellets should be hay-based (typically Timothy) and contain a fiber content of 18% or more.
Because pellets are calorie-dense, portion control is necessary to prevent obesity and discourage the rabbit from eating less hay. Adult rabbits should receive about 1/8 to 1/4 cup of pellets per 5 pounds of body weight daily.
Pellets should be uniform in appearance. Avoid muesli-style mixes that contain seeds, nuts, or colored pieces, as these encourage selective feeding and are high in unhealthy fats and sugars.
Treats, such as fruits and root vegetables like carrots, must be limited due to their high sugar content. Excessive sugar disrupts the delicate microbial balance in the cecum, leading to digestive issues and weight gain. The maximum for sugary treats is no more than one level tablespoon per 2 pounds of body weight per day, including all fruit and non-leafy vegetable treats combined.
Foods and Substances to Strictly Avoid
Several common foods are toxic or highly disruptive to a rabbit’s digestive health and must never be fed. Avocado is highly toxic due to the compound persin, and chocolate is toxic due to theobromine. All vegetables from the allium family (raw onions, leeks, and garlic) can cause oxidative damage to red blood cells, leading to hemolytic anemia.
Processed human foods (bread, pasta, crackers, and breakfast cereals) are too high in simple carbohydrates and cause severe gastrointestinal upset and obesity. Dairy products, even yogurt drops marketed for rabbits, are unsuitable and can lead to a harmful overgrowth of bacteria in the gut.
Fruit seeds and pits from apples, pears, and stone fruits should be removed, as they contain cyanide. High-starch vegetables like corn and potatoes should also be avoided due to digestive problems.