Regenerative medicine is the process of using the body’s ability to heal itself by producing living tissues to repair or replace damaged tissue or organ function. Although these biotechnologies are still in their infancy, they are advancing quickly in both the veterinary and human health spheres. In horses, one of the most common and better-recognized regenerative medicine techniques is using stem cells to promote regrowth of various body tissues in the treatment of orthopaedic conditions such as bowed tendons, lesions of the deep digital flexor tendon, suspensory ligament and fracture repair and degenerative joint disease. In dogs, stem cells are being used to help reduce pain and inflammation in such conditions as osteoarthritis as well as tendon and ligament injuries.

What are stem cells and where do they come from?
Stem cells are immature cells that naturally mature into various body cell types. They are unique in that they can be readily divided and manipulated or ‘differentiated’ into specific cells for a particular part of the body and can then be transplanted to replace damaged tissue. These cells have the capacity to either create a copy of itself by dividing or differentiate into a new cell with a specialize function, ready to replace another nerve, organ, muscle, skin or bone cell. They also contain many types of growth factors (proteins that cause cells to grow and proliferate and heal) as well as cytokines (chemicals secreted by the cells of the immune system to attack infections and damaged cells).

Stem cells can be harvested from different origins. There are two different classes of stem cells: adult and embryonic. Adult stem cells are procured from a variety of tissues, including skin, fat and bone marrow. The use of adult stem cells is less controversial as sampling does not require the destruction of the ‘host’ as with an embryo. Embryonic stem cells have more potential to differentiate into cells of any type and are, therefore, more flexible than adult stem cells although their use is still only at the experimental stage.

Why use stem cell therapy?

When damaged tissue heals, scarring is produced. The junction of the normal tissue with the scar is never as strong or as specifically functional as the original tissue normally was. This increases the risk of re-injury when these animals go back to their previous amount of exercise or competing. Using stem cells to replace the damaged tissue promotes healing while reducing the chance of re-injury. This procedure is all about helping the body heal with a tissue as close to its original architecture as possible. In other words, we supply the construction materials the body needs to repair itself.

What type of stem cells is used to treat animals?

Both horses and dogs are being treated in veterinary clinics around North America using a licensed stem cell service by Vet-Stem, Inc. Adipose tissue is utilized because it is readily available and stem cells can be collected in large concentrations. Valley Vet is pleased to be now offering Vet-Stem services to both our small animal and equine clients.

How is sample collected?

Clinically, it means the animal is sedated and the chosen sampling site is clipped and aseptically prepared. Once the sample is collected, it is shipped overnight in specialized packaging to the Vet-Stem laboratory. The next day, the stem cells are collected from the adipose tissue and shipped back to the veterinarian via overnight service. The next day (day 3), the veterinarian injects the cells into the injured tissue of the patient (tendon, ligament, joint or IV to treat certain conditions in dogs).
What diseases and injuries are currently treated with stem cell therapy?
As mentioned before, stem cell therapy is most commonly used to treat lesions of the deep digital flexor tendon, suspensory ligament, fractures and degenerative joint disease in horses. In dogs, it is most commonly used for orthopaedic conditions such as osteoarthritis, polyarthritis and tendon/ligament injuries. In dogs, the use of stem cells has the advantage that it can safely be used in conjunction with anti-inflammatory medication and other therapies for chronic osteoarthritis. Also, a certain percentage of dogs suffering from chronic osteoarthritis will be able to discontinue the use of anti-inflammatories completely once treated with stem cell therapy IV or intraarticular.

Although promising and yielding positive results, stem cell therapy still has its realties and limitations such as cost and its use for specific injuries only. For example, if a lesion in a tendon or ligament is too ‘old’ there will be too much fibrous connective tissue already present and stem cell therapy is not appropriate. Also, currently, this therapy has no value for cancer or active infections. There are also small but real risks associated with sampling and administering the cells, same as all minor surgical procedures in veterinary medicine.

What are potential treatments with stem cell therapy?
Stem cell medicine holds much promise for a variety of diseases, including liver, kidney, heart, neurologic and immune-mediated diseases. Also research is under way for ways to apply stem cell therapy in treating laminitis, spinal cord injuries, heaves and even uveitis in the horse. Stem cell research is really just in its infancy but we can already foresee a bright future for this new therapy and multiple avenues to treat our pets for years to come.

Where can I find out more about stem cell therapy and Vet-Stem?

Vet-Stem laboratory in Canada: www.avivagen.com

Vet-Stem USA: www.vet-stem.com