With regard to dogs getting a bit constipated - my last cocker, Rosie, suffered from repeat bouts of colitis after an acute bout of pancreatitis. The vet put her on Hills ID, but it wasn't until I started using a diet that contained bone meal that she firmed up and never had another bout of colitis. I found that if she had a small amount of bone meal in her diet every other day she was fine - any more than that and she would get constipated. Grace is the same, she has bone meal occasionally - twice a week at most for her or she becomes a bit constipated. Grace has already showed signs of having problems, i.e. mucus on her stools - but as soon as bone meal is introduced the problem disappears.