When it comes to diet, a rabbit’s needs are simple and pretty much the same for all of them. A domestic rabbit's diet should mirror the wild rabbit’s diet as much as possible, with plenty of hay and grass with smaller portions of greens and pellets.
Primary Diet is Grass & Hay
As long as your bunny is eating 80 to 90% hay and grass, they can be fed some vegetables as a snack each day. Vegetables for your rabbit should be free of pesticides and washed thoroughly before being eaten. Unlike what many of us have grown up believing, in part due to Bugs Bunny’s carrot habit, it’s that rabbits eat carrots. It follows in our minds that they enjoy all vegetables, but the truth is that they they need to eat their body weight in hay each day, and veggies are more of a tasty snack - not a main course.
Can I Give My Rabbit Lettuce? No!
Iceberg Lettuce is listed as a food that rabbits should not eat according to humanesociety.org and, well everyone who knows rabbit health. It is nutrient-weak compared to other lettuces - meaning it has no nutritional value - and due to it’s high water content can cause diarrhea. Diarrhea in rabbits can cause death quickly, so your bunny is better off without it.
If you want to give your bunny lettuce, offer romaine or dark leaf (no iceburg lettuce and no cabbage) and if they haven’t had it before introduce it very slowly over the course of a few days. Only add one new vegetable to the diet at a time so if the rabbit has diarrhea or other problems it will be possible to tell which vegetable is the culprit. After giving any new food to your bunny, wait to see if their excrement is soft or runny. Rabbit digestive systems are very sensitive and new foods can upset them very easily.
Vegetables to Limit and Avoid
Lots of rabbit keepers like to make their little furry friends a salad each day. If you want to give your bunny a salad, use Romain or dark leaf lettuces, never iceberg lettuce! Other vegetables to limit are celery, parsley and spinach, while other vegetable to totally avoid include corn, peas, Pennyroyal mint (toxic) and potatoes.