Stem Cell Therapy - the improved diagnostics available to treat lameness

Article by Jackie Zions (interviewing Dr. Koenig)

Prevention is the ideal when it comes to lameness, but practically everyone who has owned horses has dealt with a lay-up due to an unforeseen injury at some point. The following article will provide tools to sharpen your eye for detecting lameness, review prevention tips and discuss the importance of early intervention. It will also begin with a glimpse into current research endeavouring to heal tendon injuries faster, which has obvious horse welfare benefits and supports horse owners eager to return to their training programs. Dr. Judith Koenig of Ontario Veterinary College (OVC) spends half of her time as a surgeon and teacher with a strong interest in equine sports medicine and rehabilitation, and the other half as a researcher at the OVC.

Lameness is a huge focus for Koenig, whose main interest is in tissue healing. “I think over the past 20 or 30 years we have become very, very good at diagnosing the cause of lameness,” says Koenig. “In the past, we had only radiographs and ultrasound as a diagnostic tool, but by now most referral centres also have MRI available; and that allows us to diagnose joint disease or tendon disease even more. We are much better now [at] finding causes that previously may have been missed with ultrasound.” 
Improvements in diagnostics have resulted in increased ability to target treatment plans. With all the different biologics on the market today, Koenig sees a shift in the management of joint disease with more people getting away from steroids as a treatment.

The following list is excerpted from Equine Guelph’s short course on lameness offered on TheHorsePortal.ca. It outlines the different diagnostics available:

When asked for the latest news on research she has been involved in, Koenig proclaims, “I'm most excited about the fact that horses are responding well to stem cell treatment—better than I have seen any response to any other drug we have tried so far!”

Koenig has investigated the use of many different modalities to see if they accelerate tissue healing and has studied which cellular pathways are affected. Two recent collaborative studies have produced very exciting findings, revealing future promise for treating equine osteoarthritis with stem cell therapy.  

In a safety study, Koenig and her team at the Ontario Veterinary College have shown equine pooled cryopreserved umbilical cord blood, (eCB) MSC, to be safe and effective in treatment of osteoarthritis.  

“These cells are the ones harvested from umbilical cord blood at the time of foaling and then that blood is taken to the lab and the stem cells are isolated out of it,” explains Koenig. The stem cells are then put through a variety of tests to make sure they are free of infectious diseases. Once given a clean bill of health, they are expanded and frozen. 
The stem cells harvested from multiple donors of equine umbilical cord blood [eCB, (kindly provided by eQcell), MSC] were compared to saline injections in research horses. “This type of cells is much more practical if you have a cell bank,” says Koenig. “You can treat more horses with it, and it’s off the shelf.” There were no systemic reactions in the safety study. Research has also shown no different reactions from sourcing from one donor or multiple donors.  

In the second study, 10 million stem cells per vial were frozen for use in healing OA from fetlock chips in horses that were previously conditioned to be fit. After the fetlock chip was created, exercise commenced for six more weeks, and then osteoarthritis was evaluated by MRI for a baseline. Half the horses were treated with the pooled MSC stem cells, and the control group received saline before another month of exercise. Then MRI and lameness exams were repeated, and arthroscopy was repeated to score the cartilage and remove the chip.

Lameness was decreased and cartilage scores were improved in the group that received stem cell therapy at the time of the second look with arthroscopy.

Many diagnostics were utilised during this study. MRIs, X-rays, ultrasounds and weekly lameness evaluations all revealed signs of osteoarthritis in fetlock joints improved in the group treated with (eCB) MSCs. After six weeks of treatment, the arthroscopic score was significantly lower (better cartilage) in the MSC group compared to the control group. 

“Using the MRI, we can also see a difference that the horses treated with stem cells had less progression of osteoarthritis, which I think is awesome,” says Koenig. “They were less lame when exercised after the stem cell therapy than the horses that received saline.”

This research group also just completed a clinical trial in client-owned horses diagnosed with fetlock injuries with mild to moderate osteoarthritis changes. The horses were given either 10 million or 20 million stem cells and rechecked three weeks and six weeks after the treatment. Upon re-evaluation, the grade of lameness improved in all the horses by at least one. Only two horses presented a mild transient reaction, which dissipated after 48 hours without any need for antibiotics. The horse’s joints looked normal, with any filling in the joint reduced.
There was no difference in the 18 horses, with nine given 10 million stem cells and the other nine 20 million stem cells; so in the next clinical trial, 10 million stem cells will be used.

The research team is very happy with the results of this first-of-its-kind trial, proving that umbilical cord blood stem cells stopped the progression of osteoarthritis and that the cartilage looked better in the horses that received treatment. The future of stem cell therapy is quite promising!

Rehabilitation

Research has shown adhering to a veterinary-prescribed rehabilitation protocol results in a far better outcome than paddock turn out alone. It is beneficial for tendon healing to have a certain amount of controlled stimulation. “These horses have a much better outcome than the horses that are treated with just being turned out in a paddock for half a year,” emphasises Koenig. “They do much better if they follow an exercise program. Of course, it is important not to overdo it.”

For example, Koenig cautions against skipping hand-walking if it has been advised.  It can be so integral to stimulating healing, as proven in recent clinical trials. “The people that followed the rehab instructions together with the stem cell treatment in our last study—those horses all returned to racing,” said Koenig.  

“It is super important to follow the rehab instructions when it comes to how long to rest and not to start back too early.”

Another concern when rehabilitating an injured horse would be administering any home remedies that you haven't discussed with your veterinarian. Examples included blistering an area that is actively healing or applying  shockwave to mask pain and then commence exercise.

Prevention and Training Tips

While stating there are many methods and opinions when it comes to training horses, Koenig offered a few common subjects backed by research. The first being the importance of daily turnout for young developing horses.  

Turnout and exercise

Many studies have looked at the quality of cartilage in young horses with ample access to turn out versus those without. It has been determined that young horses that lack exercise and are kept in a stall have very poor quality cartilage.

Horses that are started early with light exercise (like trotting short distances and a bit of hill work) and that have access to daily paddock turnout, had much better quality of cartilage. Koenig cited research from Dr. Pieter Brama and similar research groups.

Another study shows that muscle and tendon development depend greatly on low grade exercise in young horses.  Evaluations at 18 months of age found that the group that had paddock turnout and a little bit of exercise such as running up and down hills had better quality cartilage, tendon and muscle.  

Koenig provides a human comparison, with the example of people that recover quicker from injury when they have been active as teenagers and undergone some beneficial conditioning. The inference can be made that horses developing cardiovascular fitness at a young age stand to benefit their whole lives from the early muscle development.

Koenig says it takes six weeks to regain muscle strength after injury, but anywhere from four to six months for bone to develop strength. It needs to be repeatedly loaded, but one should not do anything too crazy! Gradual introduction of exercise is the rule of thumb.

Rest and Recovery

“Ideally they have two rest days a week, but one rest day a week as a minimum,” says Koenig. “I cannot stress enough the importance of periods of rest after strenuous work, and if you notice any type of filling in the joints after workout, you should definitely rest the horse for a couple of days and apply ice to any structures that are filled or tendons or muscles that are hard.” 

Not purporting to be a trainer, Koenig does state that two speed workouts a week would be a maximum to allow for proper recovery. You will also want to make sure they have enough access to salt/electrolytes and water after training.

During a post-Covid interview, Koenig imparted important advice for bringing horses back into work methodically when they have experienced significant time off.
“You need to allow at least a six-week training period for the athletes to be slowly brought back and build up muscle mass and cardiovascular fitness,” says Koenig.  “Both stamina and muscle mass need to be retrained.”

Watch video: “Lameness research - What precautions do you take to start training after time off?” https://www.youtube.com/watch?v=zNHba_nXi2k

The importance was stressed to check the horse’s legs for heat and swelling before and after every ride and to always pick out the feet. A good period of walking is required in the warmup and cool down; and riders need to pay attention to soundness in the walk before commencing their work out.

Footing and Cross Training

With a European background, Koenig is no stranger to the varying track surfaces used in their training programs. Statistics suggest fewer injuries with horses that are running on turf. 

Working on hard track surfaces has been known to increase the chance of injury, but delving into footing is beyond the scope of this article.

“Cross training is very important,” says Koenig. “It is critical for the mental and proper musculoskeletal development of the athlete to have for every three training days a day off, or even better provide cross-training like trail riding on these days." 

Cross-training can mitigate overtraining, giving the body and mind a mental break from intense training. It can increase motivation and also musculoskeletal strength. Varied loading from training on different terrain at different gaits means bone and muscle will be loaded differently, therefore reducing repetitive strain that can cause lameness.

Hoof care

Whether it is a horse coming back from injury, or a young horse beginning training, a proficient farrier is indispensable to ensure proper balance when trimming the feet. In fact, balancing the hoof right from the start is paramount because if they have some conformational abnormalities, like abnormal angles, they tend to load one side of their joint or bone more than the other. This predisposes them to potentially losing bone elasticity on the side they load more because the bone will lay down more calcium on that side, trying to make it stronger; but it actually makes the bone plate under the cartilage brittle.  

Koenig could not overstate the importance of excellent hoof care when it comes to joint health and advises strongly to invest in a good blacksmith. Many conformational issues can be averted by having a skilled farrier right from the time they are foals. Of course, it would be remiss not to mention that prevention truly begins with nutrition. “It starts with how the broodmare is fed to prevent development of orthopaedic disease,” says Koenig. Consulting with an equine nutritionist certainly plays a role in healthy bone development and keeping horses sound.

The importance of identifying lower and upper limb lameness

First published in European Trainer issue 58 - July - September 2017

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In thoroughbred racing injuries to the limbs are a major welfare and safety concern and are the leading reason for horses to be out of training.

Lameness is the number one reason for a high turnover in racing stables and, as many trainers know, it has huge financial implications for the owner, trainer, and the racing industry in general. Previous investigators have found that just over 50% of horses in training in England and Germany experience lameness during training and approximately 20% of horses in the UK suffer lameness that prevents them from returning to training. With this amount of horses on lay-up, it can be difficult to run a profitable racing stable.

In addition to having an impact on the horse’s welfare and future career, severe musculoskeletal injury also poses a serious safety concern for jockeys. The main reason for a jockey to suffer injury in a race is a horse sustaining a catastrophic injury or sudden death.  Researchers in the US found that a jockey was 171 times more likely to be injured when a horse they were riding in a race died. In thoroughbred racing, the most common life-threatening injury to horses involves fractures of bones in the fetlock. Therefore, the best way we can improve safety and welfare of both horses and jockeys is to highlight risk factors for fractures in an attempt to prevent these catastrophic injuries from occurring.

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Equine lameness - Can it be measured?

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Treating Joint Degeneration the Drug-Free Way

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.
New treatment
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.
The causes
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.
Results
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 (14 October 2008 - Issue 10) ​

Nuclear scanning - the next stage in diagnosing lameness

Nuclear scintigraphy or 'bone scanning' attempts to take lameness diagnosis one stage further by predicting rather than just diagnosing fractures. It is an imaging technique that searches for an increase in bone production and thus can often pinpoint the cuase of minor lameness problems before they become catastrophic injuries.

Nuclear scintigraphy works via the highly ingenious idea of linking a mildly radioactive substance to bone turnover so that it can be measured.  A radioactive substance called technetium is joined together with a phosphorous compound and then injected intravenously into the horse. The bones of the horse use this phosphorous compound to make more bone cells at different rates depending on what is going on in each individual bone. A ‘normal' bone in an adult horse will therefore only take up a small amount of the phosphorous compound and thus only emit a small amount of radiation.  However, a bone with a stress fracture in it will take up lots of the phosphorous compound and therefore emit a large amount of radiation as it attempts to make lots of new bone cells to try and ‘fix' itself.  As a result, the amount of bony remodeling taking place in the equine skeleton can be measured by the amount of radiation emitted from a particular site using a sophisticated radioactivity measurement device called a gamma camera.
After the intravenous injection, providing that the horse is not too lame, it is exercised gently to distribute the compound evenly before its radiation is measured.  Thirty minutes later, the injection leaves the blood and soft tissue and heads for bone, therefore radioactivity readings are taken two to five hours after administration.  Horses must stand still long enough to obtain good readings and so they receive a standing sedation but no general anesthetic is required.  Although simple handheld ‘point' radioactivity scanners can be used to measure the radioactivity, large expensive gamma cameras are much better as they are situated on a steady crane, move all around the horse smoothly and take more accurate readings in a shorter period of time, thus reducing the risk of movement errors.  Bone scans can easily be carried out and analyzed in a day, although horses must remain in controlled areas overnight as they remain slightly radioactive until the next day. This does lead to slight practical disadvantages of nuclear scintigraphy – the safety precautions required when working with radiation and the necessity to stop the horse's work whilst it resides at a nuclear facility.
Nuclear scintigraphy allows for the evaluation of the entire equine skeleton, although specific regions can be imaged as required.  A computer then processes the information from the gamma camera and generates an image of the horse's bones.  Areas of increased radioactivity, which reflect increased bony remodeling, are represented as ‘hot spots.' Although these can simply reflect a normal area of increased bone turnover such as a growth plate in a young horse, a large uptake in a certain place may signify a ‘stress fracture.' A stress fracture is simply a very early fracture that is not displaced in any way.  The bone turnover is high because the bone is trying to ‘fix' itself.  Once a ‘hot spot' has identified where the problem is, x-rays and ultrasound scans can be brought in to further investigate the specific area.
Due to the expense of the equipment and the practical safety issues associated with bone scanning, it is not the sort of equipment that is found at every training center or racetrack.  Even though the radioactivity of the substance is very short-lived, many safety precautions have to be taken. The syringe containing the radioactive injection is protected from the veterinarian administering it by way of a lead shield.  All those coming into contact with the horse from that point onwards wear protective clothing, and the horse's dirty bedding is stored and then disposed of in accordance with strict radiation regulations.
Although many veterinary centers may own a handheld point scanner, the superior gamma cameras are generally found at universities and large veterinary hospitals.  The result is that bone scans are not carried out as routinely as some other less expensive, more readily available imaging techniques.  However, when ‘conventional' imaging techniques such as x-rays and ultrasound scans either fail to find abnormalities or more serious fractures are feared but not seen, then horses should undergo a bone scan.  They are most useful in young horses with severe, acute lameness and they have a number of important uses.
Firstly, their most common use is in the case of a lame horse whose specific problem has not been found by conventional veterinary medicine.  For example, ‘nerve blocks,' which ‘freeze' the leg in specific locations, may have found the area of pain but x-rays and ultrasound scans have not revealed a specific problem. If the bone scan reveals a hot spot in, for example, the lower cannon bone, then the horse is likely to have a stress fracture here. Stress fractures can be so small that in the initial stages they are not visible on x-ray and it is only when the bone has remodeled around the small fracture line that some changes can be seen.  In fact, sometimes a fracture line is never seen at all on x-ray and so nuclear scintigraphy really is the only method by which it can be diagnosed.
Nuclear scintigraphy is also useful in horses with suspected spinal or pelvic pain where x-rays and ultrasound images are inconclusive.  A bone scan can reveal a hot spot that proves the activity of the bone at the suspected location, thus confirming it as the source of pain.  The horse's back is a very difficult area to assess both clinically and using x-rays and ultrasound scans, hence the gap in the market for an influx of miraculous ‘back manipulators' and chiropractors, many of whom have very little scientific basis behind their technique.  A bone scan can prove whether there really is any bony problem behind the horse's pain, for example, a ‘kissing spine' where a horse's back vertebrae ‘rub' together or a pelvic stress fracture.
Trainers also send horses that are moving and performing poorly for full body bone scans as these animals can have multiple sites of pain.  Rather than freezing joints one by one with nerve blocks to try and ascertain which joints hurt most, the bone scan can highlight several mild hot spots, which might be troubling that particular horse.  Following assessment of these areas either clinically or using x-rays and ultrasound scans, some trainers may then choose to have several joints ‘medicated' with anti-inflammatories, lubricants and substances to increase joint health in an attempt to make the horse move more fluently and win more races.
The only drawback with using scintigraphy in this way is that bone turnover does not necessarily correlate perfectly with painful joints. Nuclear scintigraphy has a tendency to over-diagnose problems and label ‘normal' bony remodeling as injuries.  Some joints have lots of bony changes in them but actually cause very little pain or reduction in performance, whilst some very painful joints are actually caused by inflammation of the joint capsule, joint fluid and joint ligaments and thus bony turnover may not actually be increased. Therefore, proving the site of pain by nerve blocking may have in fact been more effective.  When a horse is diagnosed with two sore knees and a sore hind fetlock, we will probably believe it.  However, when horses are diagnosed with three sore joints and four stress fractures, I personally find it hard to believe.
The final important asset of nuclear scintigraphy is the speed with which it can diagnose a fracture.  Sometimes it is urgent to find out immediately whether or not a horse has a fracture. The veterinarian dealing with the horse suspects a fracture but cannot see one on x-ray. Whilst it would be possible to wait and re-x-ray the horse in a few days or weeks, the bone scan gives an instant answer and thus connections know what the problem is with their horse and how it should be treated – as a mild lameness or a fracture that must be rested in order to prevent a catastrophic injury.
At this point, readers are probably wondering why there are not more bone scanning facilities and why they are not used more regularly. This again brings us back to the fact that nuclear scintigraphy measures bone turnover and unfortunately this does not always correlate with fractures.  Whilst a bone scan is highly unlikely to miss a fracture, it may diagnose one when there is not one there. Examples of this include areas of ‘normally' high bone turnover such as growth plates in young horses (bone remodeling associated with growing), ‘bucked' shins that are remodeling but should not be treated as fractures, and some changes associated with large bones such as the radius and the tibia.  The tibia is the equivalent of the human shinbone and in the same way as we can get sore shins, horses can get sore tibias.  When horses begin training, tibias may be remodeling at quite a high rate (and thus will be picked up by a bone scan) but they should not always be treated as fractures. If I were to start road running tomorrow, my shins might become slightly sore after a few days and start to remodel to the increased work. However, rather than stopping, it would actually be better for me to carry on with my running until my shins adapt to their new work. Similarly, bone scans can make us stop training some horses fearing a fracture when they are actually at no higher a risk of fracturing than the horse in the next stall, and in fact, we are just making their bones ‘softer' for when we recommence their training.
In summary, nuclear scintigraphy may be hard for many of us to pronounce but by measuring bone turnover in the equine skeleton, it has become a very useful tool in equine lameness diagnosis. As legendary Breeders' Cup winning trainer Michael Dickinson (my uncle) says: "the phrase that sums up bone scanning is ‘peace of mind.'" There are numerous examples of horses that have had potentially fatal fractures prevented by undergoing a bone scan, which revealed that a minor lameness was actually being caused by a potentially catastrophic fracture.
Thanks to the late Dolly Green, the Southern California Equine Foundation was able to build a nuclear scintigraphy facility at Santa Anita racetrack.  It was this facility that enabled 2007 Kentucky Derby hopeful Ravel to be diagnosed with a stress fracture that could not be found on x-ray.  As trainer Todd Pletcher said, "…it would have turned into a condylar fracture if we had breezed him." Similarly, Halfbridled, the Champion two-year-old filly of 2003, was diagnosed with a stress fracture in a cannon bone and is now safely undertaking her new role as a broodmare.  Nevertheless, bone scans are not perfect.  They can over-diagnose stress fractures, they do come with certain practical safety disadvantages and they are perhaps not one hundred percent accurate at diagnosing joint pain. However, despite these limitations, they have been a great addition to veterinary medicine. They may prevent one or two horses from being trained when they are actually fit to work, but they also prevent great horses like Johar, Ouija Board, Ravel and Halfbridled from fracturing on the racetrack and for this we should be grateful. 


James Tate (26 June 2008 - Issue 6)

Shockwave Therapy - uncovering new treatments

Doctors originally used shockwave therapy more than 20 years ago to disintegrate kidney stones in their patients, then learned that the therapy can also treat tendonitis, tennis elbow, heel spurs and other ailments. Equine researchers are still uncovering everything shockwave therapy can do for horses after it was initially and successfully used in Germany in 1996 to treat lameness. Shockwaves are high-pressure, low-frequency sound waves generated by a device outside the body and focused on a specific body site. When the shockwaves meet tissue interfaces of different densities, the energy contained in the shockwaves is released and interacts with the tissue, triggering natural repair mechanisms and stimulating bone formation and blood flow.

The shockwaves can lessen or eliminate pain and accelerate healing. New York trainer Rick Schosberg has a unique perspective on shockwave therapy. He’s used it on himself and his horses. “I’ve used it for myself for tennis elbow; it helped my elbow for 90 days,” Schosberg said. “With my horses I’ve used it a couple times on injuries and it did okay for minor injuries, soft tissue and saucer fractures. It probably knocked a third off the healing time but it’s expensive. You use it for at least three treatments over a month and a half, usually every two or three weeks. As long as it‘s not abused it’s okay. You can‘t run a horse within 10 days after you use it and you have to report it every time you use it (in New York) because it has an analgesic effect.” Shockwave therapy’s impact on horse racing could not have happened if it wasn’t developed for human patients first. And that happened by accident. During experiments with high-velocity projectiles, which were being used to smash ceramic plates, an employee at a company in Germany touched the plate at the very moment the projectile hit the plate. He felt something in his body akin to an electric shock, though measurements showed that there was no electricity present. That prompted German scientists to begin researching the possible effects of shockwaves on humans in the late 1960s. The first successful disintegration of a kidney stone in a patient by shockwaves was done in 1971. Fourteen years later, experiments were conducted regarding the effect of shockwaves on bones, leading to experiments on other parts of the human anatomy.

Today, shockwaves are the first choice of treatment for kidney and ureteral stones and has morphed into treatment for other medical conditions. Will equine medicine’s use of shockwaves follow a similar pattern? The first equine disease to be treated with shockwaves was proximal suspensory desmitis, an injury to the suspensory ligament which is a major cause of lameness. A year later, shockwaves were used on a horse with Navicular Syndrome, an ailment affecting the small navicular bone in a horse’s foot and the connecting ligament. The first use of shockwaves in the United States happened in 1998 with a horse with a distal hock joint and navicular pain. All the results were encouraging. “When we first started using it, it worked okay on lameness,” Iowa State University’s Dr. Scott McClure, DVM, a leading researcher of equine shockwave therapy, said. “At this point in time, it’s been well documented for tendon and ligaments.

A lot of people think it works for stress fractures. I think there are some joint applications which we’re learning more about. Soft tissue, too. It’s been shown to increase permeability of cell walls.” He believes that increased cell wall permeability could lead to drugs which are more effective attacking tumors. “There’s potential for a lot of applications,” McClure said. “I clearly don’t think we understand all of its uses.” There are two types of equine shockwave therapy: extracorporeal generated outside the body and focused on a specific area of a horse’s body, and radial pressure waves when an applicator is pressed on the horse’s body. “The two of them get lumped together, but they shouldn’t be,” McClure said. “They’re very different. Radial pressure waves have lower pressure and more shallow penetration.” According to Dr. Stephen Adams of Purdue University‘s Veterinary Teaching Hospital in a 2002 article, studies have shown that shockwave therapy is effective treating suspensory ligament disease, bowed tendons, ringbone, bone spavin, splints, fractured splint bones, sore backs, navicular syndrome and fractures not healing properly. “Initial studies show that about 75 percent of horses treated for these conditions show marked improvement following shockwave therapy,” Adams wrote, while noting that many conditions require a second treatment to produce optimum results. “Advantages of this treatment are that no drugs are used, and horses with chronic conditions such as bone spavin, chronic suspensory ligament disease and navicular syndrome can continue to exercise.

Frequently, improvement in lameness is achieved in horses where conventional treatments have failed. Shockwave therapy is used as an adjunct treatment for fresh injuries such as recent bowed tendons with the goal of reducing convalescent time and improving the outcome.” On its website, the University of Wisconsin-Madison’s Veterinary Medical Teaching Hospital suggests using shockwave therapy on horses suffering from: suspensory ligament injury, tissue calcification, fractures or joint ankyloses, fatigue injury to bone, back pain, navicular disease and bone exostosis.

McClure documented the effect of extracorporeal shock wave therapy (ESWT) on horses with unilateral forelimb lameness in a study he co-authored with Jessica Dahlberg, Richard Evans and Eric Reinertson which was published in the July 1st, 2006 issue of the Journal of the American Veterinary Medical Association. The study focused on five geldings and four fillies and mares with lameness.

Treatment by ESWT resulted “in a period of acute improvement in lameness severity that typically persists for two days. Thus, in horses undergoing ESWT, exercise should be controlled for a minimum of two days after treatment to prevent further injury.” The reason is that ESWT has an undeniable analgesic effect. “This has raised concerns that use of ESWT to treat musculoskeletal injuries in horses may, because of the analgesic effects, result in overuse of the injured limb, causing further injury to the affected part and posing a risk to treated horses and their riders,” the study said. “For this reason, racing jurisdictions in the United States and the Federation Equestre International have adopted regulations that require a 5-to-7 day period after treatment before the horse is allowed to perform.”

Regardless, the horseracing industry, one never known to embrace change and new products, has quickly come on board in using this non-invasive treatment on their horses. “Over the last five years, it’s dramatically increased,” McClure said. “The market is starting to saturate. There’s a lot of equipment out there. In 1988, I had the second machine in the country. I think the owners and trainers have taken the bit and run with it. They’ve been very aggressive with that.” Trainer Sanna Hendricks used shockwave therapy on her multiple stakes winning steeplechaser Praise the Prince after he suffered a soft tissue injury below the pastern while winning the 2003 Grade 1 New York Turf Writers’ Cup at Saratoga Race Course. “We used shockwave therapy on him, and he responded to it,” Hendricks said in an August 30th, 2004 story in the Blood-Horse. “I took the conservative approach with him. I gave him plenty of time to rest and recover and didn’t bring him back to training until February 5th with an eye on these races at Saratoga.” Praise the Prince not only made it back to the races at Saratoga, he won the 2004 Grade 2 A.P. Smithwick Memorial Steeplechase there as a nine-year-old. If that isn’t an endorsement for shockwave therapy, what is? But shockwaves should not be construed as a panacea.

Complications can occur with incorrect use, and McClure wrote, “The release of kinetic energy at interfaces of different acoustic impedances is crucial in planning ESWT. Shock waves must never be focused on gas-filled cavities like the lung or intestine.” Meanwhile, he’s back at work, doing new studies to see just what else shockwave therapy may help.