to find out, we asked three veterinarians about their thoughts on fiber for dogs and some of the top sources of this plant-based nutrients for pups. there are a lot of puppies with chronic diarrhea, and they respond beautifully to fiber.” this is where it gets tricky because not every dog needs fiber added to their diets. whether your pet has some mild digestive issues, your vet suggests a fiber boost, or you just want to provide some occasional fiber-focused …