Mesenchymal stem cells (MSCs) are “adult” or tissue-resident stem cells. These cells are multipotent, meaning they can turn into several different specialised cell types, such as cartilage cells, bone cells and fat cells.

MSCs were first found in bone marrow, but have since been detected in many different tissues, including adipose tissue (fat) and umbilical cord blood. MSCs are naturally present in the body where they help to keep tissues functioning normally and assist with tissue regeneration following injury.

By injecting stem cells into injured tendons we can aid the healing process and reduce the formation of scar tissue, which reduces the chances of re-injury. Injecting stem cells into joints can reduce pain and increase limb function in horses with osteoarthritis.

Whilst we still don’t completely understand the underlying mechanisms, current research suggests that the beneficial effects of stem cell therapy are more likely to be via their ability to encourage improved tissue repair by the body’s own cells, rather than turning into new tendon or cartilage cells themselves.

There is now ample evidence to show that mesenchymal stem cells can have a significant benefit in the treatment of over-strain tendon injuries in horses.

In comparison with established tendon treatments, stem cell-based treatments have halved the re-injury rate following superficial digital flexor tendon injury in both racehorses and sports horses compared to conventional management.

Evidence for the efficacy of stem cell therapy for joint disease is more limited, so strong conclusions about success rates cannot currently be made. However anecdotal reports and a few recent studies suggest stem cells can offer some benefit for the treatment of certain joint diseases.

Platelet rich plasma (PRP) is another biological therapy that has gained a lot of interest in recent years.

PRP is prepared by filtering or centrifuging blood to obtain the platelet-rich fraction. Platelets contain high levels of growth factors and other proteins which may be beneficial for tendon and ligament healing and the modulation of inflammation in joints.

PRP is very quick and simple to prepare, which means it can be used almost instantly as a “horse-side” treatment which may be advantageous for the rapid treatment of severe injuries. However, to date, there is more evidence to support the use of MSCs than PRP for tissue repair in horses.

Your vet can refer your horse for treatment to our specialists in the RVC Equine Hospital.

If you choose to be evaluated and treated at the RVC, you will be evaluated by leading specialists in equine orthopaedics who will manage your horse’s advanced stem cell treatment and discuss all aspects of their conditions.

Alternatively, your vet can take a bone marrow (or fat) sample themselves and send it to our laboratory at the RVC where we will prepare the cells and ship them back to your veterinary practice 2-3 weeks later to be injected.

Bone marrow samples are obtained, under sedation, from your horse by a qualified vet, usually from the sternum (chest).

The bone marrow is then sent to our on-site laboratory, where it is processed to isolate the stem-cell rich fraction. The cells are then grown until sufficient numbers for treatment are achieved. The number of cells required depends on the size and type of injury, but typically cells are ready to be injected directly into the injured tendon or joint within 2-3 weeks.

Our clinicians will then prescribe a personalised rehabilitation programme for your  horse

Stem cell treatment acts by improving the normal repair process rather than accelerating it. Therefore, the normal time periods of rehabilitation are advised but with the expectation of improvement in the quality of the repair as time goes on.

Following treatment, your vet will provide you with a detailed rehabilitation program. Rehabilitation time will vary depending on the condition being treated but may be up to a year for flexor tendon injuries.

Regular follow-up assessment at 2-3 month intervals is recommended to hone the rehabilitation programme to the individual patient.

The treatment involves only an ultrasound-guided or joint injection which are routine procedures and so carry very little risk. It is, however, important, that they are done in a sterile fashion to minimise the risk of infection.

The procedure usually also requires sedation which carries a small risk of colic.

At the RVC, only cells acquired from your horse will be injected into them (autologous therapy).

This minimises any risks of an adverse reaction. 

Yes, almost all insurance companies cover stem cell treatment in their policies but it is probably worth checking with them before embarking on the treatment.

This will depend on the financial arrangements with the treating veterinarian.

The SCC will bill your veterinarian (or the Equine Referral Hospital of the RVC if you horse is being treated there).