In moderation, oranges are not bad for dogs. They do have acid in them, which in large quantities can cause problems such as bladder stones but in moderation they are not bad for the dogs. The peel is not good for them so make sure to peel it before giving it to the dog but the orange itself is not bad for dogs. Another problem that can be caused if given in large quantities is urine problem. They can get a condition known as struuvite crystals. But in moderation, oranges are not bad for dogs.