A New Look at Lameness

Words - 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 in 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 centers 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:

Stem Cell Therapy
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 utilized 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,” 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 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?”

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, like they practice in the UK.  

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 orthopedic disease,” says Koenig. Consulting with an equine nutritionist certainly plays a role in healthy bone development and keeping horses sound.

How HISA has affected the marketing and selling of equine supplements - What trainers need to know

Article by Ken Snyder

In 1834, Thomas Day of Day & Sons in the UK. introduced Day’s Black Drink, an elixir for horses to relieve colic, chills, “low condition” and something called “gripes.” There is no record of the ingredients, and that is probably something best left unknown.

Black Drink was the first known supplement, or product made from natural, not synthetic, substances, as this was the early 19th century. So, too, is heroin derived from a natural substance—poppies. (Created from morphine in 1874, its use on the racetrack was prevalent enough in the early 20th century to help fix races that “horse” became slang for the narcotic in recent history.)

Supplements today range from useless and quackery to many that are considered effective in horse health care by many trainers on the racetrack. In fact, the majority of  Thoroughbred trainers utilize supplements with feed.

Like therapeutic medications and illegal substances, dietary supplements are under the purview of the Horse Integrity and Safety Authority (HISA). Like their drug counterparts, HISA is instituting uniform regulations for supplements in all 50 states. The task falls specifically to the organization’s Horse Integrity and Welfare Unit (HIWU).

Good, bad, or indifferent, the intent of this organization, inarguably, is noble: to make racing safer and healthier for the horses. 

Supplements, however, are seemingly lost in the fog in the scrutiny and attention paid to perhaps the biggest problem in horse racing: medications.

There are potential hazards with supplements, however, and uniform rules across all U.S. racing jurisdictions are in place just as with medications. The key regulation that is now applicable in every HISA jurisdiction specifies that “orally administered vitamins“ and “unsupplemented isotonic electrolyte solutions by oral or intravenous administration” may be administered up to 24 hours prior to post time. This may differ from prior state regulations.

Alexa Ravit, director of communications and outreach for HIWU, outlined the objectives of this regulation and all HISA “regs” in response to an email:

“HISA’s supplements-related regulations (and in particular addressing ‘drug claims’) are intended to protect horsemen from 1) fraudulent or unproven claims of effect; 2) the unknown safety risk to horses in administering these products; and 3) products where the risk of contaminants or unknown components is high due to lack of independent quality controls.”

The task of monitoring and regulating dietary supplements is not nearly as challenging as that for medications, but it is no slam-dunk either. Also, while medications and new withdrawal times for permitted drugs might be a trainer’s focus, trainers should know that, while supplements by and large are safe, there are things to watch for with their use. 

In simplest terms, managing supplements for trainers under HISA/HIWU is following three steps: (1) reading labels (more on this below); (2) being careful in using dietary supplements in combination with approved medications; and (3) not accepting free supplements without understanding what’s on the label.

Mislabeled supplements, according to Rivet, are the major thing that can get a trainer and owner in trouble. She wrote, “If…the product’s labeling…includes a health or structure/function claim, the product is a drug, not a dietary supplement.” Also, drugs are FDA-approved and will carry that information on the label. Supplements won’t. 

In short, trainers need to look first to make sure the supplement does not say “FDA approved.” Supplement labels also should not make “structure/function” claims. HIWU lists these examples:

− Decreases or prevents exercised-induced pulmonary hemorrhaging (EIPH)

− Prevents or treats gastric ulcers
− Manages pain caused by osteoarthritis
− Controls inflammatory airway disease 

− Increases cardiac output
− Increases red blood cell production

The claims are definite, positive and apparently proven by results, warranting approval by the FDA.

Contrast these claims against what will be found for dietary supplements: 

− Sustains lung health
− Maintains gastrointestinal health
− Supports heart health
− Supports bone strength
− Promotes healthy metabolism
− Replenishes electrolytes lost through exercise and sweating

Labels on dietary supplements sound good but stop short of making a promise and, in a couple of instances, are vague at best. “Sustains lung health” and “maintains gastrointestinal health” are things you would want a horse to have after lung or gut issues are solved, and maybe skate closest to a claim like a drug. What supports heart and bone health and strength, respectively, is anybody’s guess. The same goes for promotes healthy metabolism. (Maybe the label will tell one how.) Replenishes electrolytes is a straight-up promise that evidently is achieved with dietary supplements and not drugs. (Gatorade for humans comes to mind.) 

To make another simple distinction, drugs are available only through a prescription from a veterinarian. If a trainer is getting them through another source, there’s potential trouble; but that’s for another story. Supplements are available in tack shops and/or online and do not require a veterinary prescription. 

Ravit, in response to how common it is to see supplements making drug claims contrary to regulations, only said, “It cannot be quantified.” That’s “Governmentese” for “It’s anybody’s guess.”

HISA/HIWU’s own definition of a drug, by the way, is this:

“Under the Federal Food, Drug, and Cosmetic Act, the term “drug” means a product intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease, and articles other than food intended to affect the structure or any function of the body.” That’s a mouthful to say it ought to work.; you should get results.

In case you’re wondering why supplements are not regulated by the FDA, the category name “dietary supplements” gives you the answer. The FDA defines them as a “dietary ingredient intended to supplement the diet.” Dietary supplements are not regulated for humans either.

Are they safe? You would think, given the absence of regulation, the answer would be an automatic “yes.” The FDA, however, can take action to remove supplements from the market if they are adulterated (unsafe) or misbranded (misleading). Let the buyer beware.

What a trainer can control are things to avoid, such as mixing supplements with drugs, administering too many supplements, or substituting supplements for drugs altogether. 

HIWU’s language on dietary supplements is actually a bit scary:   

“It is…the responsibility of the manufacturer to ensure the product’s safety and to market the supplement in accordance with applicable law.“

The second part of the statement should give one pause. Yes, the manufacturer is responsible for the product’s safety, but it’s the trainer or trainer’s barn help that is the last person in the literal food chain for the horse. Once a supplement is in a trainer’s hands, he or she is on their own. The safe bet is a veterinarian’s assessment of any risks and/or benefits. 

HIWU addresses this in their literature: “Supplements can interact with some medication with adverse health conditions” advising trainers to “be vigilant and discuss administration [of a supplement] with your veterinarian.”

Ravit also responded with “no comment“ to whether there have already been instances of a supplement producing a positive test for an illegal or controlled substance.

Practicing veterinarians like Dr. Rick Fischer, who has been on the racetrack for 53 years, is, as one would expect, well-versed in the difference between a drug and a supplement. He presents another issue that threatens the health and safety of horses. He and other vets are not always gatekeepers with supplements for trainers. Laymen or salesmen will approach trainers directly promoting supplements. “Worse than that, they’ll give them away: ‘Here are two gallons of this. Use it and see if you like it.’ You really don’t know what the hell you’re getting,” said Fischer.

There are other words on supplements to be mindful of. HIWU’s website warns that “’natural’ does not mean safe, nor does it mean that a product is free of Prohibited Substances.  Neither do “seals of quality assurance” that guarantee a supplement is safe and effective. In short, even practicing veterinarians recommending supplements cannot guarantee safety or effectiveness.

Fischer said there have been instances where a supplement and an approved medication have produced positive tests for banned substances. 

 HIWU’s website advises, “It is crucial to have specialized knowledge from a chemical engineer or pharmacist in order to comprehend and forecast the resulting molecules, due to the intricate interplay between the chemicals involved.” 

 Fischer expounds on the “intricate interplay” thusly: “There’s been positive tests on things that I’ve never even heard of. It’s not something that anybody in their right mind would give a horse. But the chemical breakdown when they’re in combination…who knows? 

“They’ll give you a list of all the different ingredients. Most of it is Greek to these guys and some of it is Greek to me, and I’ve been practicing for more than 50 years.”

Fischer actually parroted HIWU language in saying it would take a chemical engineer or pharmacist to be able to tell “if this molecule matches up with this molecule and what it’s going to come out as.“

Good luck to any trainer looking for a chemical engineer or pharmacist on the backside. 

Dr. Day’s Black Drink, by the way, would not pass muster as a supplement as it claimed to treat colic. As for “gripes,” there is no supplement or drug for that.