The Horse's Back

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The Crazy Logic of Saddle Fitting That You Probably Haven’t Thought About

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There’s a basic premise of saddle fitting that hasn’t occurred to a lot of people. It can’t have done, not if the tack they’re riding in is anything to go by.

To start, let’s remind ourselves that the horse’s back wasn’t designed to be sat on and it certainly wasn’t designed for saddles. This isn’t to pursue an argument about what is natural for horses or not. Yes we ride them and it’s not natural, ta-de-da.

The reason for this statement is simply to highlight the fact that inserting a relatively static piece of equipment between two living organisms in motion is, at best, always going to be fraught with complexity.

 

We have to acknowledge that when it doesn’t work, it’s usually to the horse’s detriment. Yes, sometimes also the rider, but if the rider’s copping it, the horse is usually getting it too.

 

One of my favourite statements about saddle fitting

It’s possibly a bit odd to have a fave sentence on this subject, but here’s one that leapt out at me a few years back and is still hanging around.

Ken Lyndon-Dykes, Master Saddler expressed this particular concept so succinctly in his book, Practical Saddle Fitting. Enjoy this – it’s a biggie:

“The best designed, most beautifully crafted saddle made specifically to fit an individual horse will not improve the horse’s ability to perform, benefit his welfare or increase his comfort.”

Say what? Do you feel the impact of that? Maybe you knew it already, but it never hurts to have certain truths reflected back at us as a reminder.

Certainly, having used this quote on a presentation slide in my Saddle Fit Essentials for Horse Owners clinics, I’ve found that these words often pull people up short. There’s usually a moment or two when you can almost hear the implications sinking in.

 

Let’s take that sentence apart a bit.

“The best saddle will not improve the horse’s ability to perform …” 

Let’s be clear, this is when compared to how the horse performs when free of its saddle and rider. The horse is always going to move better with no restriction or load on its back.

“…benefit his welfare… “

Again, nope, we’re not improving the horse’s welfare, but minimizing and ideally eliminating the negative impact on the horse’s welfare that comes with restriction or pain due to poor saddle fit.

“… or increase his comfort.” 

Same. When did you ever see a horse look more comfortable after you put the saddle on? What we are aiming for is simply neutral, in that the horse is as comfortable with the saddle (and rider) as it is without.

 

The fact is that saddles are there to assist the rider and beyond that are an exercise in damage limitation to minimize the effect of their own presence. 

And that’s it. There’s the crazy logic, right there.

It’s a paradox, the definition of a parodox being “a seemingly absurd or contradictory statement or proposition which when investigated may prove to be well founded or true.”

Saddles may not make a horse go better, but the well-fitted saddle definitely minimizes the negative effect that a saddle and rider may have in preventing normal action and, at worse, causing discomfort and pain.

Interesting, isn’t it? Yet once we recognize this fundamental truth, the more likely it is that we’re on the road to making wise and sensible choices that increase comfort for our horses and improve performance as a result.

Not Quite Classical… Better Lungeing for the Rest of Us

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Thinking as a bodyworker, if there were one thing I could change in the training of ridden horses, it would be the way that many people lunge their animals.

I’d be so happy if the standard practice were a simple, gentle and biomechanically correct approach that brings profound improvements to the horse’s back health and readiness for riding.

It’s not a science and it needn’t be. For most people, it’s easy to learn, easy to do and easy to continue with. At even a basic level, it conditions the horse to carry weight and to not only balance itself, but to move effectively while carrying the weight of the rider.

Every rider and horse can benefit from this, no matter the ridden goals or discipline. Horses may just happen to have a back we can sit on, but their bodies are not designed to function in the way that we ask.

Here is a simple and affordable resource that will help you to do it better: A Course in Lungeing. It’s something I’ve recommended to bodywork clients over the years, with positive results. (It does involve ditching the gadgets and moving with your horse, but you don’t mind that, do you?)

Let’s look at why I believe it’s so good.

 

© 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!

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What often passes for lungeing

Oddly enough, many people think you don’t have to learn anything in order to lunge a horse.

It does involve ditching the gadgets…

It’s assumed that you just need to buy the right equipment. In all too many cases, it’s then a matter of sending the horse in a circle, achieving as much trotting in as short a time as possible.

There are plenty of goals, including many that don’t have much to do with preparation for biomechanically correct movement while being ridden.

Lungeing to warm up the horse. Lungeing to build topline. To get the horse ‘into an outline’. To make the horse listen. To make the horse understand. To ‘get the buck out’. To get weight off the horse.

It’s also what many people do when they haven’t got time to ride. It’s not good and it’s not the best option for any horse.

 

It takes time to prepare the horse’s back

Lungeing shouldn’t be part of a rush. It isn’t a ‘hack’, ie. some kind of shortcut or saving of time and effort, adopted to fill the gap between feeding and going to work on days when there aren’t enough hours for riding.

In the last few years, a renewed interest in a more classical, biomechanically correct approach to training has brought simple, in-hand training techniques to wider audiences. Older methods that aimed to prepare horses for ridden careers, which have been overlooked in the great rush to do everything faster, have come back into focus.

This doesn’t involve sending horses in circles around a largely stationary human. It involves walking with the horse, working with it and shaping it. It’s about educating the horse to move and to carry itself in a way that is then taken forward into ridden work.

Lungeing for ‘everyhorse’

While horses differ enormously in terms of conformation, their needs are basically the same for carrying a rider. This is true no matter what discipline their athletic capabilities and fate destine them for. It is equally true for the trail riding horse.

Pien, Anglo Arabian

Biomechanically correct lungeing prepares the horse to do this. Put very, very simply, this means lungeing so that on a bend, the horse weights inside and outside legs evenly and doesn’t lean in.

Instead, this even weighting means it is able to freely lift up through the base of neck and withers, between the shoulders (i.e. the thoracic sling). Meanwhile, the hindquarters are active and load bearing. The horse moves lightly with elevation and is able to do so freely and at all paces.

Biomechanically correct lungeing helps to develop the back and teach self-carriage, which makes it humane as well as effective.

Why would anyone wish for less for their horse?  The wonderful thing is that it’s not hard to do.

 

Therapeutic benefits of correct lungeing

As a bodyworker, I have repeatedly witnessed the  improvements in horses that were helped to work correctly in this way.

Clients and associates have had success rehabilitating horses, including (and especially) ex-racehorses with serious sacroiliac dysfunction.

Fanta, 12-year-old Westphalian

The strength in their bodies, the suppleness, and the ability to work softly in a magnificent shape without any kind of restriction or force is wonderful to see.

I’ve also noticed how much horses seem to enjoy working in this way, as their body and movements develop and their spirits lift. Pride becomes visible in their movement and attitude.

These horses go on to flow under the saddle. Again: who wouldn’t want that for their horse?

The thing is, once this approach is learned, the improvements come quickly. Dramatic changes can happen through 2-3 short sessions a week. It’s not time consuming at all – and you don’t need to be into dressage to do it.

Which brings us to A Course in Lungeing.

 

So how do we relearn lungeing?

A Course in Lungeing makes these time-tested approaches available to the owners of any horse, no matter what breed, age or conformation, or ridden discipline.

It’s perfect for people who don’t want to study for qualifications or who can’t afford or manage to attend clinics with classical trainers (you can do this in your paddock).

The course was developed by German horsewoman, Babette Teschen, based on her many years of teaching correct lungeing in workshops in Europe.

Lunging training stood out as being really helpful for my work,” writes Babette Teschen. “In as much as you learn to lunge your horse according to biomechanical principles, you are doing what is best for the health and spirit of your animal partner: you give it the means to fulfill what you want of it in a healthy way.”

What I love is their strong focus on musculoskeletal health, so much so that they’ve included contributions from an equine osteopath and an equine acupuncturist.

More info and to purchase ‘A Course in Lungeing’

What you receive with ‘A Course in Lungeing’

With this training, you can help your horse to learn to bend in a circle instead of falling in, to raise its inner shoulder, and to move with the hindquarters tracking the forelegs (think of a train on the tracks rather than a motorbike on a bend).

Anthony, 5 year old Haflinger

When your horse can do this, it will be able to free up the neck and ‘let go’ from the withers. It can develop rhythm and freedom of pace, with good ground coverage. The horse’s back muscles are freed up to do their work effectively, with its hindquarters taking up the load.

 

What you’ll receive: 

  • View the first 30 pages of the book for free.
  • 250 pages of instruction material plus videos of various exercises.
  • Extensive basic information of anatomy and biomechanics.
  • Clearly presented exercises that will help you and your horse to master the problem of moving in a circle with ease and enjoyment such as the Cone Slalom, the Stepped Pathway, and many more.
  • Photos and diagrams with explanations and illustrations.
  • A Media Library with videos, and a substantial .pdf by osteopath Maike Knifka on the theme of Physiotherapy and the Lungeing Course, with supporting videos.
  • Acupressure tips from acupuncturist Patrizia Harneit on video.
  • A special on working with horses with extra paces, such as Icelandic horses.
  • Tips for working with older horses and those with health problems.

 

The book is available as a PDF in English.

More information and to purchase ‘A Course in Lungeing’

Note: this post was published in July 2019, simply because I believe in the approach.

This has resulted in many purchases of the course. I’ve been happy to facilitate that, as it helps so many horses.

 

Bondi, an Australian Stock Horse whose owner, the late Eva Thaler, introduced me to this course many years ago. 

 


 

The Very Big Problem of Dwarfism in Horses

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In this guest post, Dr. Sonja Dominik describes equine dwarfism and what the latest tests mean for horse breeders. Sonja is a Research Scientist in Quantitative Genetics at CSIRO, Australia’s national science agency.

She is currently a Superstar of STEM, appointed by Science & Technology Australia to increase the public visibility of women in science. To top that off, she was also a competitor in the 2018 series of Australian Ninja Warrior.

Sonja writes :

 

There’s small and then there’s very small.

There’s cute – and then there’s dwarfism, which isn’t cute at all.

Equine dwarfism is a very complex genetic condition. However, a few facts apply to all dwarf types in horses.

First, dwarfism in horses is caused by a disruption of the structural processes in bone and / or ligament development. It can potentially occur in any horse breed, but is most prevalent in Miniature horses, Shetland ponies and Friesians, but has also been described in Mustangs and donkeys.

All characterized dwarf types in horses are disproportional, meaning that only some parts of their bodies – eg.  their limbs – are reduced in size.

Dwarfs can suffer secondary conditions, usually due to their skeletal deformations, and multiple health problems, such as metabolic, digestive or respiratory disorders.

In genetic terms, dwarfism is a recessive condition (more on that below). Not all dwarf types are genetically characterized, but genetics tests are available for some.

Bond Tiny Tim (b.1970) was an American dwarf miniature horse breeding stallion, whose name appears throughout miniature horse pedigrees. Image copyright unknown.

 

Horses with dwarfism aren’t just tiny

Four types of equine dwarfism have been defined, based on their physical characteristics. However, there are a lot of overlaps and there are dwarf horses that are difficult to fit into any of the described types.

1. Short legs, long bodies.

Achondroplasia is the most common form of dwarfism. Affected horses have short-limbs with a normal trunk, although often with an elongated back.

The term achondroplasia actually means ‘without cartilage formation’, although that is not quite correct…. these dwarfs have cartilage, but the problem is that cartilage is not turned into bone while they are gestating.

However, this type of dwarf can lead a relatively normal life.

Foal with achondroplasia. These miniature horses can lead relatively normal lives. Image copyright unknown.

 

2. Large heads, distorted features.

Brachycephalic dwarfs have a bulging forehead, with a short and flat nasal bridge, overly large eyes, and nostrils that are higher than what is considered normal.

They also have a short neck and limbs, and often have spine deformations. This type of dwarf often has a shortened life span.

Thumbelina (b. 2001), a brachycephalic dwarf miniature, was celebrated as the smallest horse in the world at 43cm tall. Image: Brad Barket, Getty Images

 

3. Multiple deformities.

Diastrophic dwarfs can have twisted limbs and / or multiple limb deformities and other characteristics such as a domed head and roached back and a pot belly.

Due to the severely deformed limbs, affected animals would require splints or surgery to move properly.

Diastrophic dwarfs are prone to colic due to the small size of the abdominal cavity and pressure on the intestines. Image copyright unknown.

4. No bone.

Hypochondrogenesis is the most severe condition of dwarfism where the bones are not ossified at all. Affected fetuses are normally aborted before birth.

 

Here’s what we know about dwarfism genetics

Recently, a genetic test for dwarfism in miniature horses was developed at the Gluck Equine Research Center, University of Kentucky.

This tests for achondroplasia-like dwarfism, which is caused by mutations in the so-called ACAN gene.

Skull of a dwarf miniature horse compared with a full size horse’s skull. Dwarfs experience more dental problems due to the large size of their teeth in relation to their skulls. Miniature skull courtesy of S. May-Davis. Image (c) J. Clothier

Every horse carries the ACAN gene, which encodes the protein Aggrecan, an integral part of the extracellular matrix in cartilaginous tissue. Four variants of the gene have been identified that cause the above types of dwarfism – there might be even more.

 

What does a genetic test tell us?

Every horse inherits two copies of the genetic code, one from each parent. This is really important in our understanding of dwarfism and genetic test results, because all known dwarfism types are recessive conditions.

What this means is that only horses carrying two copies of affected genes, ie. one from each parent, will actually be dwarfs. Horses with one affected and one unaffected gene will be a carriers.

Thumbelina as a foal. Image: Youtube video via www.sunnyskyz.com blog.

Carriers are normal in appearance, but there is a 50% chance that they will pass the affected copy of the gene on to their offspring. This means that if two carriers are bred, there is a 25% chance that the offspring is affected by dwarfism.

 

And there’s a second gene too

As well as ACAN, another gene has been identified that causes dwarfism if it is mutated. This gene is B4GALT7, which, if mutated, leads to disrupted bone and cartilage formation. (In humans is associated with  Ehlers-Danlos Syndrome, a group of connective tissue disorders.)

This mutation is prevalent in the Friesian breed – affected horses have also short limbs, deformation of the rib cage, and hyperextension of the fetlock joint5.

Dwarf Friesian foal with hindlimb hyperextension. Image copyright unknown.

Dwarfism in the Friesian horse is also recessive and again, only horses with two copies of affected genes are dwarfs.

 

Why is dwarfism only present in certain breeds?

There are a number of possibilities.

  • Selective breeding may have played its part: horses with favorable features have sometimes been carriers of a defective version of a gene.
  • A single copy of the defective gene might have had a favorable effect on small size, so animals with a single copy might have been preferentially selected.
  • However, as size in horses is influenced by a large number of genes, the defective version of the genes might be linked to versions of other genes that cause small size.  It could have “hitchhiked” during the selection for small stature.

In this way, selection for smaller stature, obviously without genetic testing, has led to a higher frequency of the defect gene in the Miniature horse population.1

It is less clear which favorable feature might have been selected for in the Friesian horse, although we do know that the stallions Paulus 121 (b.1913) and Us Heit 126 (b.1917) each sired 7 dwarf foals.

Image copyright unknown.

 

What is skeletal atavism?

Skeletal atavism has similar physical features to dwarfism, with horses being deformed and with shortened limbs. It also occurs in Miniature horse and Shetland ponies.

The characteristics include abnormal bone growth, which is evident in the upper limb bones, including the ulna in the forelimb and the fibula in the hindlimb.1

In atavistic horses, the ulna extends from the humeroradial to the carpal joint (ie. elbow to knee) and the fibula from the femerotibial to the tarsal joint (ie. stifle to hock).6

This can cause splayed legs and create movement difficulties.6

Atavistic ulna and radius from a miniature horse (L) and normal ulna and radius (R). Miniature bone sample courtesy of S. May-Davis, TB bone sample J. Clothier (Image (c) J. Clothier

Atavistic characteristics have been observed in fossil records of earlier ancestors of a species, and have then reappeared quite recently.4  The earliest report in recent times was in Shetland ponies in 1958.7

Genetically speaking, these are not new mutations, but are ones that became dormant, only recently being re-expressed.2

Like dwarfism, atavism is a recessive condition, which means that affected horses need to have inherited an affected copy of the gene defect from each parent.

 

How can we avoid dwarfism?

The occurrence of dwarf horses is a matter of chance, but the fewer horses in a population that carry the affected genes, the lower the chances that two carrier horses will be bred and produce a dwarf foal.

To avoid dwarfism and reduce the frequency of affected genes in a population, carriers of affected genes should not be bred.

Koda, adopted permanent resident at Yarrambat Veterinary Hospital in  Australia, has experienced “a barrage of health problems and major surgical procedures” Image (c) thevetsurgery.com.au

How do we know that a horse is a carrier?

There are only two ways to know if a horse is a carrier:

1. If the horse ever had a dwarf foal, it is clearly a carrier.

2. Genetic testing.

In North America, you can test for dwarfism in Friesians here and for dwarfism in miniature horses here.

“Cuteness overload”… or a health and welfare issue? Image (c) SWNS.com

 

What tests are available?

Genetic tests to identify carriers of the variants that cause dwarf appearance are now available for dwarfism in Miniature horses and Friesian horses, and for skeletal atavism in Shetland ponies.

Genetic testing is straight forward. All that is required is a sample of hairs, including hair bulbs, that is sent to a testing laboratory and the test will establish if the sample originates from a carrier of defect genes that cause dwarfism.

Hair follicles are all that is needed for a low cost, genetic test. Image (c) www.imagenesmi.com

 

If a test is positive, it can be devastating. However, if your horse is a carrier and is only bred with horses that are also tested and shown to be unaffected non-carriers, all offspring will be unaffected.

However, the defect gene will still be passed on to the offspring, with a 50% chance to create a new carrier and dwarfism gene remains in the population.

That means you’re depending on future owners to do the right thing – and they very well may not do so.

 

Finally, here’s how different versions of the ACAN gene affect the horse (adapted from Eberth et al. 2018)

Examples of some mutations. Image (c) Genetic Testing at Gluck – https://gluck.ca.uky.edu/disease-mutation – click on image for link.

 

If you love horses and love your breed, then the truly responsible option is to test every horse you breed from. If you then breed and sell a mare or entire horse colt that’s a carrier, it remains that someone less responsible than yourself may then breed it to an untested stallion. 

 

If you’ve enjoyed Sonja’s writing, do take a look at another of her public posts on The Conversation’s blog, about the giant cow Knickers – yes, THAT giant cow.  Read her article: Yes, Knickers the steer is really, really big. But he’s far short of true genetic freak status

 

 

References:

  1. I.J.M. Boegheim, P.A.J. Leegwater, H.A. van Lith, W.Back (2017) Current insights into the molecular genetic basis of dwarfism in livestock. The Veterinary Journal 224: 64.
  2. J.M.Cantu, C. Ruiz (1985) On atavisms and atavistic genes. Ann Genet 28: 141.
  3. J.E. Eberth, K.T. Graves, J.N. McLeod (2018) Multiple alleles of ACAN associated with chondrodysplastic dwarfism in Miniature horses. Animal Genetics 49: 413.
  4. B.K. Hall (1995) Atavisms and atavistic mutations. Nature Genetics 10: 126.
  5. P.A. Leegwater, M. Vos-Loohuis, B.J. Ducro, I.J. Boegheim, F.G. van Steenbeek, I.J. Nijman, G.R. Monroe, J.W.M. Bastiaansen, B.W. Dibbits, L.H. van de Goor, I. Hellinga, W. Back, A. Schurink (2016) Dwarfism with joint laxity in Friesian horses is associated with a splice site mutation in B4GALT7. BMC Genomics 17:839
  6. Rafati, L.S. Andersson, S. Mikko, C. Feng, T. Raudsepp, J. Pettersson, J. Janecka, O. Wattle, A. Ameur, G. Thyreen, J. Eberth, J. Huddleston, M. Malig, E. Bailey, E.E. Eichler, G. Dalin, B. Chowdary, L. Andersson, G. Lindgren, C.-J. Rubin (2016) Large Deletions at the SHOX Locus in the Pseudoautosomal Region Are Associated with Skeletal Atavism in Shetland Ponies. G3 Genes Genomes Genetics 6: 2213.
  7. Tyson, J.P. Graham, P.T. Colahan, C.R.Berry (2004) Skeletal Atavism in a Miniature Horse. Veterinary Radiology and Ultrasound 45 (4): 315

Links:

https://thehorse.com/18222/12-miniature-horse-health-risks 

https://www.ofhorse.com/view-post/Equine-Dwarfism-Not-a-Desireable-Trait,

https://www.facebook.com/aryathedwarfpony/photos/facts-about-equine-dwarfism-1-equine-dwarfism-is-most-prevalent-in-miniature-bre/800155847006325/

http://www.littlemagicshoes.com/page5.html

https://www.vgl.ucdavis.edu/services/horse/Friesian.php

https://gluck.ca.uky.edu/sites/gluck.ca.uky.edu/files/2022-01/dwarfism_miniatures_submission_form_april_2017.pdf

http://www.friesianhorses.com.au/healthdwarfism.htm

All You Need to Know About the New Biological War on Worms

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Australia has declared a new war on worms – and this time it’s biological.

You may already have read about this wonder from Down Under, the “world’s first biological control for grazing animals”, on the equine news sites.

Instead of dosing our horses continually with chemical wormers, we now have the option of fighting parasites by feeding our horses an innovative new product: a supplement containing a fungus that passes through the horse to kill the larvae in manure.

Called BioWorma®, this new supplement can, through continued use as part of a worming strategy, dramatically reduce roundworm larvae in pasture by an average of 84% (across livestock species – the lowest effect recorded has been 50%, the highest over 90%).

Perhaps, like me, you have quite a few questions about exactly what this means for horse health.

Recently, I caught up with Chris Lawlor, CEO of International Animal Health Products, the commercial producer of BioWorma®, at the Australasian Equine Science Symposium 2018. (The other partners included scientists at CSIRO, Australia’s national science agency.)

Between his presentation, our conversation and other reading, I’ve taken the opportunity to get my head around this remarkable new product. 

 

© All text copyright of the author, Jane Clothier, https://thehorsesback.com. 

 

What is this biological wormer and how does it work?

Duddingtonia flagrans is a nematophagous fungus that is found in pasture and manure around the world. The term nematophagous is Greek and means ‘worm-eating’.

Good news for horse owners is that once the fungus is resident in a manure pile, it creates a microscopic net that traps, paralyses and consumes the larvae of parasitic worms – and in particular, nematodes.

This means it basically consumes the larvae of large and small roundworms, the gastrointestinal parasites that are amongst the dangerous for our horses.

 

How do we use this biological wormer?

Duddingtonia flagrans has been added to a protein meal that we can feed as a supplement to horses (vets can obtain it ‘neat’).

It is best used strategically within a rotational paddock system. In practice, this means that you take the following recommended steps:

  1. Deworm your horse or herd with conventional chemical wormers. All horses in the same paddock must be treated, or this process becomes pointless.
  2. Conduct a fecal egg count to see how much your horse is shedding.
  3. Once the egg count is low, move your horse into a fresh paddock just after deworming (yes, I know this isn’t always possible, but please read on – there’s another option).
  4. Give Bioworma in the horses’ feed, so that fresh manure in the new paddock is hosting worm-eating Duddingtonia. Repeat once or twice a year, until roundworm egg counts are negligible.
  5. Continue to use chemical dewormers for tapeworms, bots, neck threadworms, etc.

If you’re not in a position to rotate paddocks but are able to clear manure from your paddocks, then you can:

  1. Deworm your horse or herd with conventional chemical wormers.
  2. Conduct a fecal egg count to see how much your horse is shedding.
  3. Once the egg count is low, give Bioworma in the horses’ feed, just after deworming.
  4. Continue clearing manure from the paddock.
  5. Give Bioworma in the horses’ feed, once or twice a year, until roundworm egg counts are negligible.
  6. Continue to use chemical dewormers for tapeworms, bots, neck threadworms, etc.

Here’s the current research paper that covers the equine trials, in the July 2018 issue of Veterinary Parasitology. It’s Open Access so everyone can read it.

 

Exactly which parasites are targeted?

Duddingtonia flagrans loves consuming the larvae of the following worms:

  • Large strongyles (large red worms), including Strongylus spp., Triodontophorus spp. and Oesophagodontus spp
  • Small strongyles (small red worms or cyathostomes), including Cyathostomum spp., Cylicocyclus spp. and Cylicostephanus spp
  • Stomach Hair Worm (Trichostrongylus axei)
  • Ascarids (Parascaris equorum)
  • Threadworms (Strongyloides westeri)
  • Pinworms (Oxyuris equi)

It doesn’t have any effect on:

  • Tapeworms, which have an intermediate host – the forage mite, which isn’t on the Duddingtonia menu.
  • The larvae of the botfly (Gasterophilus), which lays its eggs on the horse’s legs or coat.
  • Onchocerca cervicalis (neck threadworms), which are not gastointestinal and are transmited by culicoides flies.

So, you’ll still need to deworm for tapeworms with a praziquantel or pyrantel product, and for bot larvae and neck threadworms with an ivermectin or moxidectin product.

Even so, that’s a lot of worms taken care of with this product, including the most dangerous of the lot.

 

And what’s the dosage?

As mentioned earlier, vets can buy straight Bioworma®, while horse owners can buy Livamol® with Bioworma®.

I have to be honest and say that I’m a bit puzzled by this – Livamol® is an existing nutritional supplement from International Animal Health Products, which is marketed as a coat conditioner.

This means you’re actually going to be paying for two products, one of which you may not really want or need. It doesn’t appear to be necessary to the effectiveness of Bioworma®, so this appears to be a purely commercial decision. I understand that a carrier is needed for this to be administered in feeds – but why not simply a protein meal, which would presumably be cheaper?

That said, the 20 years’ development period is a long time for a company to hang in there, and return on investment has been a very long time coming.

Moving on… Dosage per 100kg bodyweight is 100g per horse per day. This doesn’t sound much if you only have one horse. If you have more, it does add up.

It needs to be fed during seasons when larvae are thriving, so definitely the warmer months of the year.

Another point to bear in mind is this. If you live in a warmer, more humid zone where parasites thrive (eg, north and north eastern coastal areas of Australia), you’ll need to use it more often.

None of this means it isn’t a great development! Just that there’s more to consider – it’s not simply a case of feed this product and say goodbye to using chemical wormers.

 

Is it safe – and when can we buy it?

Yes, it’s safe for domestic animals, wildlife and the environment. It’s been tested in 19 trials and three different safety studies for everything from environmental effects to toxicology and residues before being licensed by the Australian Pesticides and Veterinary Medicines Authority (APVMA) in May 2018. (You can see the APVMA’s licensing sheet here.)

BioWorma® will be available in Australia and New Zealand from July 2018, and in the US soon after. Europe will come on board within the next year or two.

I’ll add price information once this is available.

Questions, thoughts or comments? Join us at The Horse’s Back Facebook Group. 

 

An Unwelcome Side Effect: Transitional Vertebrae in Horses

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They can lead to scoliosis, spinal arthritis, flexion and straightness problems, saddle fit issues, secondary lameness, hoof problems and soft tissue trauma. So, what on earth are transitional vertebrae, and why haven’t we heard more about them?

To answer the first part of that question, transitional vertebrae are hybrids that appear where one group of vertebrae changes to another. They show mixed features of each group.

They can be found along the spine, where:

  • the cervical (neck) meet the thoracic vertebrae,
  • the thoracic meet the lumbar vertebrae,
  • the lumbar meet the sacral vertebrae (sacrum),
  • where the sacrum meets the caudal vertebrae (tail bones).

As for why we’ve not heard much about them, the answer is probably that they’re rarely identified while a horse is alive.

However, they can lead to some very real problems in the living horse due to the asymmetry they cause along the spine – and they’re far more common than you might think.

A transitional vertebra at L1. (c) J. Clothier

 The affected process or rib can hurt when the horse bends into it, as the abnormal rib/process is literally ‘stabbing’ into soft tissue.”

 

© All text copyright of the author, Jane Clothier, https://thehorsesback.com.

 

Thoracic and lumbar transitional vertebrae

Here are the three main types of variation, as shown in this diagram from one of the few research papers to mention this issue.

Here, we’re going to look at the first two – labeled A and B – which are the most common manifestations.

The three kinds of thoracolumbar transitional vertebrae. (c) American Journal of Veterinary Research. (Annotated in green by J. Clothier) Haussler, K.K., Stover, S.M., Willits, N.H. Developmental variation in lumbosacropelvic anatomy of Thoroughbred racehorses (1997); American Journal of Veterinary Research, 58 (10), pp. 1083-1091

A ‘process-like rib’ at T18

Labeled ‘A’ in the above diagram, this is a transitional vertebra at T18 (the last thoracic vertebrae) – a rib that thinks it might be a transverse process, lacking an articulation or joint with the vertebral body.

A normal facet on one side, a non-articulated process-like rib on the other (c) J. Clothier

Instead, the process-like rib is solidly attached, meaning there is no independent movement whatsoever. At its end point, it’s joined by costal cartilage to the preceding rib, partially restricting that rib’s movement, too.

This is a problem, as the caudal ribs are not directly attached to the sternum because they need to move more.

The abnormality can be on one or both sides of the vertebra, although single side is most common.

A ‘rib-like process’ at L1

Labeled ‘B’ in the above diagram, this is a transitional vertebra at L1 (the first lumbar vertebrae). Again, it’s usually one-sided, although two sides also occur.

Here, we’re looking at a transverse process that rather than being fairly short, wide and flat, instead extends outwards like a misshapen rib. There’s no articulation with the vertebral body.

The first lumbar vertebrae (L1) of this Quarter Horse mare is a transitional vertebra. (c) Melissa Longhurst, www.equinebodybalance.com.au 

The above image shows an abnormal L1 found in a Quarter Horse mare. This mare was asymmetric throughout her body, and had a history of unsoundness both fore and rear throughout her lifetime.

Effect on the horse

Scoliosis is the major effect of transitional vertebrae. It’s an asymmetry that in these cases can be lifelong and permanent.

I’ve seen it a few times now in skeletons and on horses that have subsequently been euthanized for unrelated reasons – the spine curves in the affected direction, ie. the horse’s ‘short side’ is the same as the abnormal rib/process that is causing restriction.

The above bones were from a TB gelding who was in his late teens. Over his lifetime, the additional pressure on the side of the abnormal L1 had caused greater bone development in the vertebra further forward. In this photo, T18, the last thoracic vertebra, has been cut to show this impact.

Cases are highly individual and the degree of impact depends on how abnormal the vertebra is, plus other factors affecting the horse’s musculoskeletal balance – including tack and riders. However, we can consider the following points.

There can be an obvious localized effect:

  • The affected process or rib can hurt when the horse bends into it, as it is literally ‘stabbing’ into soft tissue.
  • The attachments of the deep, short muscles involved in segmental stabilization at L1 and T18 are affected, also affecting proprioception and posture.
  • The abdominal muscles involved in breathing and flexion during locomotion are restricted over an affected T18.
  • The diaphragm inserts onto T18, meaning its function is also affected.
L1 transitional vertebra on the left side causing scoliosis along the spine, including the sacrum. (c) Melissa Longhurst, www.equinebodybalance.com.au

 

This can affect overall spinal health and biomechanics:

  • Scoliosis means that bending to the affected side can be uncomfortable, while bending to the opposite side can be highly limited.
  • Achieving straightness may be impossible. Scoliosis can extend through the withers and into the neck.
  • Impinging transverse processes and vertebral arthrosis at other vertebral joints further limit movement.
  • These restrictions make lifting the back problematic. 

And then there can be a host of secondary effects:

  • In the heavily pregnant mare, existing discomfort due to a T18 may worsen.
  • Achieving saddle fit is difficult on an asymmetric horse with scoliosis.
  • Abnormal loading can lead to recurrent lameness and persistent hoof issues.
  • Unrelated pathologies can scale up uncontrollably, as the horse cannot compensate effectively.

 

More on this Topic

Take a closer look at the vertebrae featured in this article (Equine Healthworks is my practice page in NSW, Australia – also on Facebook.)

 

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Can we spot transitional vertebrae in the living horse?

Yes, sometimes.

Unilateral transitional vertebra at T18. (c) J. Clothier

As this TB mare (above and below) was unable to maintain weight due to the physical stresses she was experiencing, her rib outline was fairly clear.

In her case, the last rib felt wider and flatter than the other ribs. The space between the rib and the point of hip was also noticeably narrower on the affected side (although this would be true of any horse with scoliosis, it’s a matter of putting the picture together, sign by sign).

The problem is visible here. This mare’s body condition and tension reflects the stresses caused by the T18 transitional vertebra, which was later confirmed at necropsy. (c) J. Clothier

There were other reasons for suspicion. Even when all the surrounding tissue was relaxed, there was no ‘spring’ when the rib was palpated with a flat hand. That’s not definitive, but it’s a cause for concern.

Do something that most people never do – stand on a fence or mounting block and take a photo down the horse’s spine, when it’s standing square…”

This veteran grey Arabian, below, is one I’d also consider a suspect. Again, we can see a very obvious protruding last rib on the offside and a lack of straightness. Even with musculoskeletal bodywork and spinal mobilization, the rib remained just as pronounced.

Arabian mare with a suspect rib. Photo: J. Clothier

Incidentally, I’ve also worked on this horse’s offspring, and the younger horse has the same profile to the ribs, on the same side, accompanied by a history of inexplicable back pain – and lack of straightness. 

Note: It’s important to eliminate other causes first, as horses will often have this appearance at the last rib, without it being caused by a transitional vertebra. What’s happening is that the rib is protruding because the vertebra is immobilised in a rotated position. When chiropractic, osteopathy or bodywork restores mobility to the spine, the rib returns to its normal position. 

 

Ongoing hoof issues

In the bay TB mare, spinal asymmetry (scoliosis, with bend to the right) had led to excessive loading of the near fore. This was no doubt compounded by constantly training and racing in a clockwise direction, plus the classic long toe/low heel frequently found in ex-racehorses.

As a result, her near fore had constant hoof wall separation, bacterial infection (seedy toe / white line disease) and a deep P3 problem that would never come right.

Here’s the hoof capsule and P3. Yes, the poor girl suffered, despite extensive efforts to reconstruct that hoof.

P3 and hoof capsule, near fore, TB mare. Photo: J. Clothier

 

Patreon members can view videos of this mare and further photos. Go to: www.patreon.com/thehorsesback for more details.

 

The TB gelding mentioned earlier also had chronic issues in the opposing fore hoof, with wall separation, damage to P3 and evidence of earlier laminitis.

 

How many horses are affected?

Who knows? The study mentioned earlier (Haussler et al, 1997) found that 22% of Thoroughbreds examined at necropsy, having died or been euthanized at the racetrack, had thoracolumbar transitional vertebrae.

Transitional vertebra at T18 (above ground skeleton, damaged by scavengers)    (c) J. Clothier

 

To date, I’ve come across 3 in above-ground skeletons (2 x T18, 1 x L1), plus one in a horse later euthanized (1 x T18). These were TBs and Australian Stock Horses.

And as mentioned, I’ve suspected the T18 issue here and there amongst clients’ horses.

Although found mostly in Thoroughbreds, transitional vertebrae are seen across a range of breeds. And certainly, with equine dissection having taken off in quite a big way in the equine care industry, more and more of these anomalies are being observed.

 

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Should we be concerned?

The answer is, inevitably, both yes and no.

On the positive side, if the numbers harbouring this problem are as high as it seems, we have to assume that many horses are coping just fine. 

For as with any musculoskeletal anomaly, horses can compensate very well.

However, when another problem is added to the mix, things can head south very quickly indeed.

And it can all happen without us ever knowing that a skeletal anomaly is an underlying factor. When this happens, owners often have a lot of unanswered questions about their horses – and often large vets bills.

Transitional vertebrae at T18. (c) J. Clothier

It’s the TB or TB-derived breed horse that is most likely to present this (although not exclusively). If you’re buying one and you view a horse with an obvious T18 that really stands out, you might want to get that checked.

At the very least, do something that most people never do – stand on a fence or mounting block and take a photo down the horse’s spine, when it’s standing square or close to square.

If there’s a clear scoliosis along the spine, be cautious (this is a good rule of thumb anyway, no matter what the cause is). If you see an overly pronounced rib on the concave side, be doubly cautious.

And if you believe your horse may have one, the answer is the same as always: be aware, take a 360 degree approach in ensuring that hooves, tack, training and riding are as good as they can be, and your horse will have the best possible chance of functioning well without cause for concern.

(c) Melissa Longhurst, www.equinebodybalance.com.au