The Background -
Lameness resulting from joint degeneration or osteoarthritis (OA) is one of the most prevalent diseases affecting horses and the most common reason that vets are called out to competition horses. OA causes inflammation of the joint lining and progressive destruction of articular cartilage that covers the ends of the bones composing a joint. This destruction decreases both the natural shock-absorbing function and the range of motion of the joint, ultimately resulting in lameness in the affected animal.
Conventional treatments for joint disease include reduced
or altered exercise regimes, bandaging, the use of anti-inflammatory
agents, anti-arthritic drugs, artificial joint fluid and
corticosteroids. For many years these treatments have helped to improve
the condition of horses’ joints and subsequently helped maintain their
overall soundness. Yet the fact is that all of them offer only limited
efficacy; some are associated with side effects and the fact that some
of them involve the administration of prohibited substances creates a
headache for trainers.
With these factors in mind, perhaps it’s not surprising that a completely new form of ‘drug-free’ treatment is attracting increasing interest from both the equine vets and trainers. While it’s still early days, its advocates believe that it may, over time, prove to offer a more effective and side-effect free way forward for the management and treatment of equine joint disease.
The new treatment, which is gaining an increasing foothold in the UK, US, Europe, Australia, South Africa and Saudi Arabia, is called an ‘autologous’ treatment because it effectively involves the horse healing itself.
A range of in-depth studies are underway to test the efficacy of autologous therapies and, while not yet conclusive, initial research results and anecdotal evidence are proving encouraging.
So, let’s examine how it works. Joint cartilage destruction is caused by a number of substances that increase when inflammation occurs in the joint.
Laboratory and clinical research has shown that one of the main substances responsible for cartilage destruction is interleukin 1 (IL-1). A multitude of research has also shown that antibodies produced against this cartilage-destructive substance can have a beneficial effect in arresting cartilage damage. A protein called IL-1RA has proved particularly helpful in this respect.
Treating the problem
The autologous treatment involves harnessing the regenerative and anti-inflammatory properties of the horse’s own blood cells, including IL-1RA to combat the IL-1, and encouraging damaged musco-skeletal tissues to heal. Effectively then the horse heals itself, a huge potential advantage for hard-pressed trainers trying to juggle horses’ treatment regimes around racing commitments.
The treatment involves a veterinary surgeon taking blood from the horse with a special syringe containing specially treated glass beads. The syringe is then incubated for 24 hours during which time white blood cells locate onto the beads and produce the regenerative and anti-inflammatory proteins.
After incubation, the syringe is placed into a special centrifuge to separate the serum from the blood clot and create a solution known as Autologous Conditioned Serum (ACS) – effectively a type of ‘anti-inflammatory soup’ with boosted levels of IL-1RA and other regenerative proteins. The ACS is then decanted into three to five vials for later intra-articular injection by the vet into the affected joints of the horse to reduce inflammation and initiate cartilage healing. Typically, three treatments are recommended for optimum clinical effect whilst the horse remains in training or is rested.
A study published in 2005 and carried out at Colorado State University examined the efficacy of the ACS therapy compared to a control (placebo).
Sixteen horses were involved in the trial. Eight underwent the ACS therapy and the remaining horses were treated using saline solution. The horses were injected with the protein intra-articularly at weekly intervals for one month and then monitored for therapeutic success until day seventy of the trial. Factors measured included lameness, movement in the joint and a determination of the volume of synovial fluid.
The study demonstrated that compared to the control group the horses treated with the new therapy showed improvement in lameness and swelling.
Further examination histologically showed that there were also significant reductions in cartilage erosion with the ACS therapy compared to the control group.
The ACS process also encouraged the concentration of IL-1RA, the protein that promotes healing, to increase in the affected joints until day 70 showing that the benefit of the treatment is not short-lived.
Veterinary surgeon Dr. Thomas Weinberger, Müggenhausen, Germany, who led the study, commented: “The arthrosis study clearly demonstrates that the ACS Therapy is an efficient and safe alternative to common therapeutic interventions.”
The late Prix d’Amerique winner and world record trotter Victory Tilly is known to have undergone the treatment successfully.
The experience so far
So, what do equine vets make of this revolution? Consultant Equine Surgeon Cedric Chan BVSc CertES(Orth) DiplECVS MRCVS says the results he’s experienced so far have been encouraging but it’s too early for definitive conclusions.
A RCVS and European Recognised Specialist in Equine Surgery, who runs NW Equine Referrals, UK and France, based in England, Chan says: “I became interested in the therapy as a new physiological form of joint treatment for OA after attending a lecture by Professor Wayne McIlwraith and also using it at one of my referral centers in France, which was using it based on Orthogen’s (the company which first developed the treatment) experience.”
He has, in particular, used the treatment after arthroscopic surgery where OA had been demonstrated.
Neal Ashton, BVet Med Cert EP Cert ES (ST) MRCVS, shares Cedric Chan’s views: “The Autologous Conditioned Serum is now regularly considered at Oakham as an option for intra-articular joint disease in a range of joints. It’s proved particularly effective in treating horses which have been non-responsive to steroids.”
Ashton treats a high percentage of competition horses which are competed regularly and cites a key advantage of ACS as its flexibility when fitting in treatment around events. “Certainly trainers and riders seem to understand and are attracted by the concept of the horse healing itself,” he comments.
Andy Bathe MA, VetMB, DipECVS, DEO, MRCVS, Head of the Equine Sports Injuries Clinic at Rossdale & Partners (Newmarket, England) and another user, says: “I was the first user of the new therapy in the UK. Over the last eighteen months we’ve been pleased with the usefulness of this product in treating our practice population of racing Thoroughbreds, as well as on our referral population of a broader range of horses.
“We’ve found it helpful in the management of traumatic joint disease in racing Thoroughbreds, which have only been partially responsive to corticosteroids.
We’ve had some noticeable successes in helping high quality horses achieve the kind of success they deserve. We have also found beneficial effects in soft tissue injuries such as tendon and ligament injuries. It’s a very exciting technology and one which certainly adds to our armory when trying to treat injuries in these athletic horses.”
Lanark-based Clyde Vet Group recently treated the first horse in Scotland and Andrew McDiarmid BVM&S, Cert ES (Orth), MRCVS, head of the practice’s equine division, says: “While the use of this treatment is in its early stages, preliminary results are encouraging and it is definitely an exciting addition to our therapeutic range of treatments in the management of equine lameness. It represents new territory for equine vets and may herald the start of a completely new direction in treating joint disease.
At the moment, we, like other clinics, are primarily using it to treat cases that have not responded to conventional therapies.”
So, what’s the conclusion so far? “At its best, the therapy has proved extremely effective,” says Neal Ashton. “While it hasn’t worked in every case, I’ve treated racehorses which have gone on to win races and eventers which have got round Badminton and Burghley – something they would have struggled to do the year before.
ACS has a well-deserved place in our toolkit of treatments for joint disease.”
With more research indeed planned and in-depth studies underway, the development of autologous therapies could well be a key area to watch for 2008.
Howard Wilder (