My family and I had a yorkie for 16 years that had some health conditions improve as a result of starting her on a raw diet at age 4, which she appeared to thrive on until her very late years, at which point everything changed when her kidneys started failing, she could no longer handle the raw meat. In retrospect, I also think she was not getting enough nutrients, probably minerals, because she got quite thin and developed a curve in her back. We did not give her the more "offensive" tripe and organ meats, though she was kind of sensitive and some things would not stay down - she would throw up every time I tried salmon or any fish, if she would even eat it. Being a toy purebred, she had some of the common problems, i.e. bad teeth, but she never needed an operation for her slippy knees, and never had tumors or cancer, no diabetes, etc., and her hot spots cleared within months after going raw at age 4.
My holistic vet did say that all our pets are damaged due to vaccinations and the like, and so the course tends to be different with each one, she has found that some do very well on raw, and others need more cooked food.