I've read that citrus is a 'no'. Mine love berries - I give them the raspberries that have gotten a tad too ripe on the vine. Seriously, their favorite green is dandelions, so I make sure I don't pull them all up
. They love a little cooked rice...again that is a moderation thing as it's just empty calories and too many carbs, I've read, will heat them up too much in hot weather. Oh, and frozen banana! Especially great on a hot day. I'll never have to waste that last banana that has gotten too ripe.
