The term cereals refer to various edible grains which may include rice, corn, oats, rye, sorghum, wheat, millet, maize, and so on obtained from cultivated grasses. Botanically, they are considered caryopsis fruits that have a germ, bran, and endosperm.
However, this term could also loosely used to mean any grains including legumes (soybeans, beans, peas, etc.), and pseudocereals (such as buckwheat, quinoa, and chia).
Can my bunnies have cereals
Rabbits should not be given cereals whether they are whole grains or processed ones including your favorite ones such as Honey Nut Cheerios, Cheerios, Raisin Bran, Granola, Honey Bunches of Oats, Frosted Flakes, Life, Apple Crunch, Corn Flakes, among others.
Unprocessed or whole-grain cereal are not only rich sources of fats, oils, carbohydrates but also proteins, vitamins, and minerals. The processed ones are still high in starch and have some additives. Even those that do not have additives are still not safe for these pets.
Why shouldn’t you give them cereals when they form an important part of human’s daily substance especially in developing nations? Here are some of the reasons why we do not recommend them.
Tummy and tooth problems
As PETA notes, “feeding your rabbit cereal—like muesli, processed food made up of flaked maize, peas, pellets, grains, and seeds—can lead to tooth and tummy problems.” This is similar sentiments expressed by RSPCA Victoria that warns against grains, nuts, seeds, beans, biscuits, sweets, breakfast, pet cereals, and any other poisonous plants.
Rabbits depend on foods that have high-fiber but low energy foods such as hay especially timothy hay where brands like Kaytee Timothy Hay won't let you down . The high fiber help in ensuring their ever-growing teeth wear out and they have healthy teeth as well as promoting gut motility and a healthy gut. Therefore, instances of furballs will be high since the high amounts of indigestible fiber helps in eliminating any ingested fur since rabbits cannot vomit it out.
On the other hand, these grains are low in fiber meaning they may lead to GI stasis. To make matters worse, they are high in fats, oils, and carbohydrates, something a rabbit’s hindgut digestive system cannot handle properly. You should expect a shift in the gut and cecum flora or cecal dysbiosis accompanied by diarrhea, gas, bloating, as well as other problems including enteritis.
Assuming your bunny can handle the high fats, carbs, carbs, and oils these grains, he or she is bound to gain in weight and become obese. Obesity in bunnies often affects this animal's ability to groom well, be active and be involved in cecotrophy. Furthermore, the excess fat can lead to hepatic lipidosis as well as intestinal problems.
We noted a source  that was ok if you give your rabbits “unsugared whole-grain cereals such as Corn Chex, Cheerios, and bite-sized Shredded Wheat.” We still won’t encourage you to give your bunnies cereals for the reasons we have stated. We understand they may be safe, but they are not healthy.
Even in their natural environment, these animals hardly get a chance to munch nuts, seeds, and grains. Stick to their right diet that is over 80% hay, some 10-15% fresh foods (leafy greens mainly with occasional treats of fruits and leafy vegetables) while the rest can be high fiber pellets like Small Pet Select Rabbit Food Pellets.
Do not forget the water. It is very essential. Bunnies need an unlimited supply of clean, fresh drinking water. During winter, ensure the water does not freeze (inside their water bottles or bowls).