Bodywork

Revealed: the Common Equine Elbow Arthritis You Won’t Read About in Textbooks

November 19, 2013 by Jane @ THB 144 Comments

Sometimes, a person from outside a profession successfully identifies something that has been unnoticed, overlooked or wrongly assessed for a long, long time. Coming from another direction, they see something that has been hidden in plain sight, simply because nobody looked there before.

Update: this post was written with Dr Sharon May-Davis’s support in 2013.

© All text copyright of the author, Jane Clothier, https://thehorsesback.com. No reproduction of partial or entire text without permission. Sharing the link back to this page is fine. Please contact me for more information. Thank you!

One lady who’s working in the field

If you’re looking for a different set of eyes for equine musculoskeletal pathologies, they don’t come much sharper than those of Dr Sharon May-Davis. Few people have the razor sharp eye she has for a hidden pathology or condition in the horse.

Teaching biomechanics, Sept 2013 — *Sharon, seated, teaching biomechanics, Sept 2013*

Sharon is also a biomechanics expert and – significantly – a practical anatomist. She has been conducting private equine autopsies for many years – it’s not for nothing that she’s been labeled The Bone Lady and Equine CSI.

She also uses these 2-3 day dissection workshops to teach equine professionals and horse owners more about how their horses move and the damage their bodies can incur as a result of breeding, illness, injury or work.

Sharon is therefore uniquely placed to provide a source of raw data that is all but unparalleled.

Evidence from the dissection table

Some years ago, Sharon noticed an unusual action in the elbow of horses. She mentioned this to qualified practitioners and was informed that this action was quite normal. Not convinced, she began videoing horses prior to dissection and, within a short period of time, was able to match this action to a change in the elbow.

*Humerus, radius and ulna, showing damage to cartilage*

Not to beat around the bush, it’s an unusual form of degeneration in the horse’s elbow joint that involves all three bones. It’s a form of osteoarthritis that strikes the humeroradial joint and the ulna, causing deep and dramatic gouges into the cartilage, and eventually eroding bone.

When the joint is opened up, blood is frequently found in the synovial fluid (haemarthrosis). The fluid also displays decreased viscosity.

This is more than a little bit odd, as arthritis of the elbow is supposed to be rare in the horse.

Yet Sharon has found it to be present in numerous horses that have been euthanized under veterinary supervision for completely unrelated reasons.

Note: that’s not just some horses, but many.

Do you know where the nuchal ligament attaches on the cervical vertebrae? You think so? Evidence from the dissection table might prove you wrong – read more about Sharon’s findings on the nuchal ligament’s lamellar attachments…

This equine arthritis is visible in the living horse

The vital connection from video to dissection has enabled Sharon to indicate the presence of the elbow osteoarthritis in the horses she had been treating as an equine therapist.

It’s easy to spot, being a noticeable jarring in the elbow as the horse moves downhill – a kind of double action. Significantly, it’s what can be termed a gait anomaly, rather than lameness.

Does it sound – and look – familiar? It’s very likely that you’ve seen it in horses before and wondered what it was. The fact is that it’s so common, many people think it’s a normal action. It’s not. It’s a form of equine arthritis.

Sharon tells us she has seen the elbow problem in all types, breeds, sizes and ages of horses. Some affected horses have been elite dressage and eventing competitors. Interestingly, the problem is only presenting in ridden and driven horses.

If never worked, horses appear to remain forever free of this particular joint change.

Why the fuss – isn’t this just regular arthritis?

No. Arthritis of the horse’s elbow is considered to be rare in equine veterinary medicine.

*How it should look: healthy radius and ulna (unridden horse)*

The key to why it doesn’t often get diagnosed and is considered rare could be the absence of visible lameness. The arthritis identified by Sharon does not cause a distinctive lameness in the horse, although it does bring on a notable gait change, with the double step in the joint’s motion on the downhill.

Riders of such horses often just feel that their horse is a bit ‘off’, feeling a hesitation in the movement, but without being able to define the point of origin.

There are a couple more reasons why it’s not very visible: first, the action of the elbow is highly integrated with the overall shoulder action, and second, the massive triceps muscle has a further stabilizing effect on the joint.

*Radius and ulna of ridden horse, showing cartilage wear and blood in joint*

And even if the elbow is explored, the relatively tight joint space means that degenerative problems are rarely seen in diagnostic imaging, although inflammation can show up in thermographic images.

When, unusually, a problem has been recognized and vets have attempted a corticosteroid injection of the joint (which happens to be the most difficult joint to access), blood has been found to be present.

A closer look at Sharon’s findings

Sharon May-Davis first presented some of her findings into elbow arthritis at a conference in Australia in February 2013: the Bowker Lectures at the Australian College of Equine Podiatherapy. Presenting alongside Prof Robert Bowker and Dr Bruce Nock amongst others, she discussed the club foot in the horse, and noted how the elbow degeneration she observes on the dissection table is always worse in the forelimb with the more upright hoof.

If the condition is bilaterally present, it unfortunately appears worse on the side with the slightly upright or higher hoof. What’s more, and according to Sharon, this also applies to the limb where an inferior check ligament desmotomy (surgery undertaken with the aim of correcting an upright hoof) has taken place and the ligament has later reconnected.

She has, as already mentioned, since established that it can occur in any ridden or driven horse. Here, she describes the problem in her own words.

“The action looks like a slip and or clunk into the shoulder or a shudder or a sliding / slipping action. It depends upon your perspective. The actual change in the action begins when the foreleg is in the ‘Stance Phase’ during the stride as the limb goes into the posterior phase of the stride. It is more obvious going down a hill.

“So far, 100% of ridden horses exhibit this condition to a varying degree (under dissection). Horses not ridden and with no abnormalities do not exhibit this condition (under dissection). Horses in harness also exhibit this condition.

“What does the joint look like? There appears under dissection to be substantial degradation in the cartilage of the humerus, radius and ulna.

“Most horses appear to handle this condition and continue with a normal life if not pushed to extremes. Although this sounds career-ending, in fact it is not. Once the horse gets through the worst of the wear pattern they re-settle in the joint and continue on with work.

“High level competitors require joint support to help sustain the elbow and other joints that may compensate for the change in action.

“Horses that jump are more inclined to land with straighter forelimbs. Be mindful that jumping and downhill work could possibly make the condition worse.

“Riders often feel instability in the horse’s forelimbs when traveling downhill and some even question the horse’s proprioception.

“Bodyworkers massaging the triceps (particularly the lateral triceps) actually exacerbate the condition as the massage releases the cast-like formation that this muscle provides.”

Here are some more examples of the elbow in action.

More research is needed, but so is support

Humerus and radial bones of ex-racehorse, showing arthritic wear — Humerus and radial bones showing arthritic wear

Despite finding and documenting a huge number of dissection cases involving this particular issue, all unaided and unfunded by outside bodies, Sharon has consistently met with brick walls and skeptical responses when she has put the information forward to relevant authorities.

Why? It’s not as if she’s new to this. She has previously identified congenital malformations in the caudal cervical vertebrae of thoroughbreds, and in the atlas of Spanish Mustangs, as well as asymmetries in the femur structures of racehorses due to racing (published in the Australian Veterinary Journal).

She isn’t looking for funding (although she obviously wouldn’t say no), but would like to have this research taken up for the benefit of all ridden and driven horses. The sooner the problem is recognized and investigated, the sooner that episodic pain in the horse can be recognized, with appropriate joint support or rest given where appropriate.

And the sooner we can all learn more in our great drive towards improved equine health, the better. As Sharon says,

“In truth, we are still in the dark. Seeing it is one thing, analyzing it and providing a preventative program is something totally different.”

More Information

Sharon May-Davis, PhD, M. App. Sc. (Ag and Rural), B. App. Sc. (Equine), ACHM, EBW, EMR was the Equine Therapist for the Modern Pentathlon Horses and the Australian Reining Team at the Sydney 2000 Olympics. She has worked with the Australian Champion from seven differing disciplines and has a particular interest in researching the musculoskeletal system. She also conducts clinics and seminars in relation to her work and regularly presents in the Northern and Southern hemisphere.

© All text copyright of the author, Jane Clothier, www.thehorsesback.com. No reproduction of partial or entire text without permission. Sharing the link back to this page is fine. Please contact Jane for more information. Thank you!

Scabbed, Scalded and Sore – Wet Weather and Your Horse’s Skin

February 3, 2013 by Jane @ THB 3 Comments

It’s not much fun being hit by a years’ worth (or more) of rainfall in a few days, as dwellers on Australia’s east coast are yet again experiencing.

In the aftermath of the storms, we often witness a problem common to horses caught in the big summer deluges of the tropics and sub-tropics.

Please note: if your horses has been trapped in deep water, as has happened in some areas of NSW in 2021, your local veterinarian or emergency veterinary services are your first port of call. This post is very much aimed at horse owners in non-emergency situations with non-traumatised horses.

It was originally published after ex-Tropical Cyclone Oswald hammered the South East Queensland and New South Wales coast for several days in January 2013.

The Cause: Mud Fever, aka Greasy Heel

There’s no doubt about it, Aussie owners aren’t as familiar with mud fever as owners in countries that are far more – well – muddier. Hailing from England, I know about it only too well. Yet in this wide brown dry land, where it also goes under its local name of greasy heel, it’s far less common.

Or at least, it was less common. I’m seeing a lot more in ~~2021~~ 2025 than I did in 2013.

The cause of the swelling and crusting skin we see with mud fever is a reaction to the early stages of bacterial or fungal infection.

Put simply, during the periods of unrelenting rain, the skin becomes softened and the many microscopic scratches around the pasterns and lower legs are exposed (imagine tiny scabs going soft).

The ‘bugs’, which thrive in damp conditions, enter these tiny scratches and abrasions. As the horse’s body starts to fight the invaders off, the swelling occurs.

Not all horses will develop the problem further, as it depends on how strong their immune systems are. Some will fight it off. But while there’s visible swelling, possibly accompanied by redness on white legs, sometimes with crusting skin and the beginnings of scabs, the horse’s body is in defense mode.

The problem usually affects the hind legs more than the front, but as it progresses, all four legs can be affected.

Partner in Crime: Rain Scald

Rainscald, also known as rain rot, is caused by the same bacterial agents and is also a form of dermatitis. The bacteria cluster in the damp, warm zone at the base of the hair, next to the skin.

You don’t see the signs as quickly as with greasy heel, but you may notice your horse has increased sensitivity along the centre line of the back – especially if they are rather overweight and have a ‘rain channel’ down the middle.

Where Does Greasy Heel Come From?

Both rainscald and greasy heel/mud fever are caused by an invading dermatophilus or staphylococcus. Greasy heel may also be caused by fungal infections such as dermatophytes.

The microbes that cause rainscald are often already living on the skin of horses, without causing any problems. However, during a period of heavy rainfall, especially in our warm regional climate, they become more active and release ‘zoospores’.

They get happy: they breed.

The spores infect the skin where it’s weaker, with the discharge then clogging into the familiar paintbrush tufts of hair and scabs after a few days.

It’s entirely possible that some paddocks present horses with the greasy heel and rainscald bugs more than others. I’ve certainly had horses that were fine until they changed properties and then suddenly seemed to ‘pick something up’.

Why Is This Such a Problem After Storms?

Good question. It’s not as if we don’t regularly get 2 or 3-day episodes of non-stop rain. The high incidence of swollen legs relating to mud fever may be due to several things. Shall we speculate?

Was the weather extremely hot before and after, and maybe during the event? The conditions may have been particularly favorable to the bacterial activity.

If there’s rain and also high winds, it’s likely that horses stopped moving around as much.

Lack of movement leads to poor circulation, which leads to fluid build-up anyway, as well as reduced resistance to nasty little pathogens.

But in truth, I don’t know for sure. I’d be interested to hear other ideas. (There’s a comments section at the end.)

Whatever the reasons, I still feel it’s best to come down hard on problems like mud fever or rainscald, as they’ll only come back another time, making your horse uncomfortable and setting you to work on it all over again.

Are These Skin Problems Serious?

These infections can be surprisingly painful for the horse. If your horse has greasy heel and scabs form, and your property is still flooded or at the least muddy, then you need to act quickly if it’s not to become a more serious problem.

The horse needs to flex at the fetlocks whenever it moves, so if the scabs remain on the pasterns, they will crack repeatedly and the lesions beneath will grow larger.

(This is why the condition is also known as cracked heel.) Your horse may well become lame.

Rainscald is painful for the horse even before the ‘paintbrush tufts’ appear. It will remain so until the scabs have all come away and the skin beneath has healed.

Horses severely affected by rainscald may develop a fever, become depressed, lose their appetite and become lethargic.

They may also have swollen lymph nodes… these are all signs of a body defending itself against pathogens.

How to Treat the Bacteria

Once you realize you’re looking at infection, it becomes more apparent that something needs to be done. There are many suggested remedies you can try once the reaction has started – here are a few.

The initial swelling should subside with movement and exercise, as the lymph fluid is shifted away.

If the horse has developed scabs, you can soften and remove these before applying treatments.

I’ve previously used aqueous cream for small scabs, which soaks and lubricates them, so that they then slide off gently. I’ve also seen paraffin oil or olive oil suggested. If the scabs are covering much larger lesions, you may need to progress more slowly, over several days, as removal will be painful for the horse.

Here are some treatments you can try, recommended by different people in the equine industry.

A diluted iodine solution can be used on the legs, to zap the bacteria.
For greasy heel and rainscald, an anti-microbial shampoo is another option for scab removal – Maloseb, normally used for cats and dogs, is gentle and contains chlorhexidine gluconate (2% content).
For rainscald, you can ease off the scabbing at an early stage, either with an oil-based product, or even with olive oil, before rinsing the back with iodine. Use it well-diluted or it may sting.
Products used by vets and medical staff containing chlorhexidine gluconate offer a gentle antibacterial action. Microshield is a good product (5% content) that can be diluted and used on horses’ legs and backs. You can buy it online or from Chemists Warehouse in Australia.
A poulticing product such as Tuffrock can be applied to the affected areas. This has some antibacterial properties – if scabbing is present, it’s better to also use an antibacterial agent.
The herbal approach is to use coconut oil on the lower legs. You could also try using this before the rains come, providing you have advance warning, so that a protective layer is built up. This can help prevent bacteria from entering the skin.

Make Greasy Heel Go for Good

If infection is present, you may need to work on the area for a few days running to ensure that the bacteria are well and truly zapped. You want to reduce the chances of it recurring – ridding your horse’s skin of the bacteria is definitely one way to do that.

That’s not to say it’ll never happen again, but as ever, prevention is better than cure.

One of the most helpful things we can do for our horses is to work on their underlying condition, boosting their immunity through use of probiotics to improve gut function, while providing adequate nutrition and mineral supplementation.

And – well, I would say this – bodywork will ensure the upper layers of tissue, including the skin, are nourished and functioning as they should, while circulation is good.

Extreme weather is never easy to deal with, but with a bit of organization, we can ensure our horses come safely through it without experiencing an unnecessary degree of discomfort and even pain.