Too much sugar in a bird's diet has been reported to cause severe problems in the digestive system. Like with people, diets that are high in sugar can precede diabetes. This has been reported in many cases when the bird's diet consisted of high-sugar treats and not enough healthy foods.
Because refined sugar has been heavily processed, there is little nutrient value left. Too much refined sugar can not only lead to diabetes, but it can also contribute to yeast infections, heart disorders, high cholesterol, and calcium imbalance. Too much sugar has also been linked to feather plucking, irritability, anxiety, and nervous disorder.
The best kind of sugar comes as natural sugars which are found in fruits and in sweet vegetables like corn.
Reference: "The Healthy Bird Cookbook" by Robin Deutsch
