In moderation, clementines are a safe treat for dogs. The citric acid in clementines is unlikely to cause digestive problems. However, clementines have a lot of sugar, and too much sugar can upset a dog's stomach.
A clementine treat should be limited to one or two segments per day. Other healthy fruit snacks for dogs are cantaloupe, apple, pear and pumpkin. Excessive snacking on fruit or other foods sometimes leads to canine obesity. Treats should not be more than 10 percent of a dogs daily caloric intake. When treats are offered, a dog's regular food should be reduced by the same amount of calories to prevent weight gain.