The Vet-Stem company has invented a way to separate stem cells from the fat tissue of horses, dogs, and cats.  Once injected back into the body, the stem cells can regenerate into several different types of tissues, including tendon, ligament, bone, cartilage, cardiac muscle, and liver.  According to the Vet-Stem website, this technology has been used for horses since 2003 and the company recently expanded its use to dogs and cats.  Stem cells are currently being used to improve arthritis in the knee, hip, and elbow and for soft tissue repair of tendons and ligaments.  Success stories