Hi, Hoping someone has a suggestion for a sugarless source of fiber for my Murphy. He's been a little constipated and his Vet recommended canned pumpkin but it has "natural sugar" in it. His Vet then recommended Squash baby food, but that has "natural sugar" in it also. I' ve been adding some water to his food (he eats only canned food - the varieties of Fancy Feast that are recommended for Kitties with Diabetes). Other than that I am really stumped - any suggestions??? Thanks so much!