Hi we have a 21 week old french bulldog and changed him from puppy kibble onto a raw food diet, all approved by our vet. We went down last night for a one week check on the raw feed and mentioned he was constipated and she said it was fine, his body was just getting used to it. This morning however he was howling in pain, never heard him make this noise before. We had to manually get the poo out (dog life is so glam) What can we do to help him?