Prevention is the ideal when it comes to lameness but practically everyone who has owned horses has dealt with a lay-up through an unforeseen injury at some point.
Ontario Veterinary College’s Dr Judith Koenig provides tools to sharpen the eye for detecting lameness, review prevention tips and discuss the importance of early intervention. She also outlines current research on healing tendon injuries.
Koenig 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 Ontario Veterinary College (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 in diagnosing the cause of lameness,” she said.
“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 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 people getting more away from steroids as a treatment. Below, are some of the diagnostics available, as outlined on Equine Guelph’s short course on lameness offered on TheHorsePortal.ca.
Using an anaesthetic agent (a drug that causes numbness, such as carbocaine) in one area of the leg
|– Help determine what area is causing the lameness|
Also called X-rays Allows veterinarians to see the bones.
|– Looks for injury or changes to the bone, such as fractures, evidence of arthritis, calcification|
Allows veterinarians to see the soft tissues such as muscles, ligaments and tendons.
|– look for issues in these areas, such as a lesion on the tendon
– you may also see small fractures on ultrasound
Advanced form of X-ray that gives a highly detailed picture of the bone.
Can produce a reconstructed 3-D image.
|– can help with a quicker and more detailed diagnosis and may help guide a more appropriate treatment plan|
Can create detailed images of soft tissue and bone.
|– can be used to get a clearer picture of what’s going on in the knee, hock, lower limb and hoof capsule|
Considered a diagnostic surgery. A small camera called an endoscope is placed through a small incision and used to look at a joint.
|– can be used to evaluate and treat problems with the joint, such as small chip fragments and osteochondrosis dissecans (OCD) fragments.|
Stem Cell Therapy
Koenig has investigated the use of many different modalities to see if they accelerate tissue healing and has studied which cellular pathways are affected, but she is 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,” she said.
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) in mesenchymal stem cells (MSC), to be safe and effective in the 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,” Koenig explains. 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) MSC were compared to saline injections in research horses. “This type of cell is much more practical if you have a cell bank,” Koenig said. “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 and then MRI and lameness exams were repeated and arthroscopy 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 used during this study. MRI’s, 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.
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 look 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.
Research has shown adhering to a veterinary-prescribed rehabilitation protocol results in a far better outcome than paddock turnout 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,” emphasizes 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 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,” Koenig said.
“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 commencing exercise.
Prevention and Training Tips
While 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.
Many studies have looked at cartilage quality in young horses with ample access to turnout 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 (such as 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 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, and 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,” Koenig said. “I cannot stress enough the importance of periods of rest after strenuous work. If you notice any type of filling in the joints after a 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. Horses should also have enough access to salt/electrolytes and water after training.
During a post-Covid interview shown below, 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,” she said. “Both stamina and muscle mass need to be retrained.”
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 warm-up 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, and working on hard track surfaces has been known to increase the chance of injury.
“Cross-training is very important,” Koenig said. “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 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.
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 a horse has 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 said she cannot 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 orthopedic disease,” Koenig said.
Consulting with an equine nutritionist certainly plays a role in healthy bone development and keeping horses sound.
Judith Koenig, Mag vet med, Dr med vet, DVSc, is originally from Austria and went to Canada in 1996 after graduating from vet school to gain research experience and complete the research for her MSc. Following a large animal internship at the Ontario Veterinary College she went to Oregon State University where she did a one-year large animal fellowship. The year in Oregon gave her good exposure to Western Pleasure horses as well as Walking horses, which complemented her previous experience with sport horses and racehorses. Koenig returned to the OVC for a three–year large animal surgery residence with a concurrent graduate degree (DVSc). Koenig became board certified with both the American and European College of Veterinary Surgeons and started to work as faculty in Large Animal Surgery at the Ontario Veterinary College in 2003. She developed a strong interest in Sports Medicine and became board certified with the American College of Veterinary Sports Medicine and Rehabilitation (equine) in 2016.
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