Blueberries are not toxic to rabbits. They should be fed very sparingly or not at all. Fruits are high in sugar and can lead to problems with a rabbit's gastrointestinal tract. A rabbits diet should consist of timothy hay available at all times, pelleted rabbit diet, and vegetables. Treats should be fed sparingly. Water should be available at all times.
I would not feed your rabbit blueberries. Fruits are high in sugar. Sugar should be limited in rabbits to promote gut health, prevent obesity, and prevent diabetes among other metabolic diseases. A rabbits diet should be comprised mainly of fresh timothy hay and a high quality pelleted rabbit diet. Vegetables, treats, and any fruit offered should be kept to a minimum and comprise no more than 10% of the diet. Water should be available at all times.
No it can kill them try other plants and veggies such as lettuce.