grapes...
I have heard of people feeding gps grapes before, but I'm not sure if they are ok to have often. Make sure you feed a lot of leafy greens like romaine lettuce, kale, dandelion greens, parsley, celery, spinach (occasionally), and bell peppers. An occasional baby carrot is ok. I like to feed fruits as a treat every once in a while, because they do not carry the same vital nutrients as the veggies. They are more like fillers.