Haven't heard of that but I do give them snacks of sliced apples and carrots. I try to make their midday snack healthy. Either a fruit or veg. Never onions or chocolate or macadamia nuts, all toxic to dogs. Also rasins or grapes. If you want to make homemade treats stay away from these. Peanut butter is also a good treat for dogs. Just give them about a quarter teaspoon...they will LOVE you forever :)