Stem cells have the potential to regenerate tissues without the production of scar tissue that is generally associated with the healing processes.  Stem cells are immature cells that do not yet have a specific job in the body but can form into a particular type of cell. Stem cells work very similar to PRP by using the chemotactic factors and cytokines to attract the bodies own healing cells to the area improving the quality of healing that occurs post injury.  Stem cells can be used to treat tendon, ligament, joint, and meniscal injuries.

Two of the most common sources of adult stem cells are bone marrow and adipose tissue (fat). Bone marrow is composed of a modified form of blood, stem cells, growth factors and other miscellaneous components. Bone marrow contains growth factors, which are thought to help heal tendons. The most-studied type of growth factor is insulin-like growth factor-I (IGF-I). Once injected, it has an anti-inflammatory and growth encouraging effect. The process involves removing bone marrow and separating the fluid (serum) from the cells. The fluid is frozen and then the cells are cultured in the laboratory to increase their numbers, which averages two to four weeks. Once there are enough cells, they are added back to the fluid and injected into the tendon

Prior to administering stem cells, veterinarians will decide whether to use autologous or allogeneic stem cells. Autologous stem cells are harvested from the horse’s own body that are injected after proliferation into the injured tissue(s). Allogeneic stem cells are harvested from a different horse. Autologous cells traditionally have been thought of as safer to use than allogeneic, as they are native to the horse’s body rather than from another horse. There are some concerns about the immune response horses might produce if injected with allogeneic stem cells. Evidence, however, suggests that allogeneic cells do not cause adverse reactions when introduced in equine joints or injected into tissues. Allogeneic cells are available for use more rapidly, as they must proliferate only for a few days rather than weeks after harvest. Some horses produce larger quantities and higher quality stem cells than others (meaning the cell’s characteristics are more predictable and consistent), so using allogeneic cells from a donor horse may mean higher-quality cells.