I feed only raw and really like it for my guys. The change was probably more evident for me in my Wylie - who was older and in his life had first eaten kibble, then I homecooked, then moved to raw. His fur definitely changed, he became less itchy, but it was his TEETH that really changed. His teeth were at their worst when I was cooking for the boys. I don't know how *long* after I switched to raw that his teeth changed, but I eventually noticed that they just cleared up. He is 4.5 yrs old and has never had a dental, and I don't brush his teeth - and they're really quite gorgeous.
My Marcel was ~10mths old when he started raw and he also had health issues as a puppy, so I can't track his changes as clearly. But he does SO well on raw, his teeth are almost spotless.
As far as the question "how long before you see changes" - every dog is different, and for some you may see changes within a month, for others who really need health improvement, it could be longer. You will see almost immediate changes such as much smaller poos, non-smelly poos that almost disintegrate, great doggy breath etcetera.
Hope that helps.
