Rabbits are strict vegetarians but that doesn't mean they can consume all vegetation. There are several common food items that are toxic to rabbits. Some foods that are completely safe for other animals including humans may have an ill effect on the sensitive digestive system of rabbits. Before allowing your four legged friend to munch on your lunch, make absolute certain that the food is safe for a rabbit to eat.
The seeds of several fruits are poisonous to rabbits. The seeds actually contain cyanide which is a highly toxic compound even to humans. However, the small amounts found in these foods typically do not affect humans but can affect rabbits. The seeds of apples and pears and the pits of apricots, plums and peaches contain cyanide compounds and should not be given to rabbits. Cherry pits are also toxic to rabbits but many parts of the cherry tree should also be avoided including the limbs, twigs, and bark.
There are other foods that contain cyanide but are rarely seen on a rabbits do not eat list. Small amounts of cyanide are found in almonds, soy, cassava roots, bamboo shoots, millet sprouts, and mangoes. Interestingly enough, cyanide can also be found in spinach but doesn't appear to have any ill effects on rabbits.
Certain vegetables that can be frequently found cooking in kitchens across the world should not be fed to your rabbit. Parsnips and rhubarb are two such vegetables. Parsnips contain the toxic "psoralens" and become even more potent when exposed to light. Rhubarb contains oxalates that prevent the absorption of calcium. Spinach also contains oxalates but generally rhubarb and spinach will not become deadly unless consumed in large amounts.
What looks and tastes great on your typical veggie salad can be harmful to your pet. Avocado and mushrooms should be kept from rabbits. A common mushroom found in many stores "Agaricus bisporus" or the button mushroom was shown to cause cancer in research mice. The avocado contains "persin", a compound that is toxic to many animals including rabbits. The meat of the avocado, pit, and the leaves and branches of the avocado tree all contain this deadly toxin and should not be given to any pet.
Some plants that are common in backyard gardens are poisonous to rabbits though the fruit or vegetable that it produces is not. A rabbit should be kept away from gardens that contain these various plants. Tomatoes, eggplant, potatoes, and sweet potato plants are all potentially dangerous to a rabbit's system. The root of the mustard plant and fresh lima beans (uncooked) should also be avoided.
Aloe Vera is a familiar household plant that is generally used for medicinal purposes. It has also been used for consumption as a homeopathic remedy for a variety of ailments but should never be given to rabbits. Coffee beans and the "eyes" that grow on potatoes also contain toxins that are harmful to rabbits. Chocolate, grapes, onions and raisins are known to be toxic to dogs and many owners avoid these food products also with their pet rabbits.
Owners who believe that their rabbit has been poisoned by any of these foods should seek veterinarian care immediately. The ASPCA also offers an Animal Poison Control Center service that is available 365 days of the year, 24 hours a day for a nominal fee. It is highly recommended to not share any foods with your pets if you are unsure of its safety. That food may be safe to put in your mouth but it's not always safe for your rabbit.