Snores, Yawns & Stretches: A Horse-Guided Massage

In You can massage a horse? Of course! I wrote about Oliver, the first horse I fully assessed and treated on the last day of the equine massage therapy course. Since then, over the past 6 weeks or so, I have been visiting Oliver’s barn once a week and giving treatments to other horses. So far, I have worked on Ebony, RT, and Willie. This is an invaluable opportunity to practice my skills and develop a routine – health check, assessment, full-body massage – or so I thought. It’s not always as straight forward as that.

What I’ve learned over the last several weeks is that, although guidelines and a general approach are good, the most important thing I need to do is listen. Mr. Ed and BoJack Horseman aside, horses can’t talk. They can’t tell me where they are feeling tension or pain, whether there’s an area they want me to focus on or a particular spot I should avoid. These are things I look for during the assessment, but it isn’t always obvious. Likewise, if I’m applying too much pressure, the horse may simply shift or move away, or, as was the case with RT, display a bite threat.

Knowing which signs to watch for to gauge whether the horse is enjoying the treatment or not is key! One horse may have a particular problem area that, when found, will elicit any number of positive responses, a droopy lip, a soft eye, a relaxed posture, a release of gas, a stretch. A couple of weeks ago, Ebony lowered his nose to the floor and started snoring as I worked on his shoulder. This week, he seemed intent on having me spend 90% of my time massaging his neck, ears, jaw, and forehead.

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Part of my routine when I enter the stall is to set up my space by placing my step stool in the corner and putting some diagrams on the wall. Two weeks ago, Willie laid down while I was doing this. Of course, I took full advantage of the opportunity to crouch down to his level and be still for a moment. I also couldn’t resist getting a picture of the regal fellow in repose.

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Ebony, on the other hand, didn’t want to wait for me to set up today. Rather, he sidled up to me, leaning in with his neck! He continued to direct me by nudging me with his nose as I attempted to do a health check and physical assessment. However, I couldn’t quite determine where he wanted me. Shoulders? No. Scapula or withers? Not quite. He did assume a more relaxed stance when I massaged his “armpit”, with my left hand on his anterior pectorals and my right working his posterior pecs and biceps, he widened his stance and relaxed his head. However, it wasn’t long before I received another nudge, to his hind end?

Normally, the buttocks and hips are spots that most horses really lean into. They exert a lot of force with their hind legs and generally love having these areas massaged to relieve the muscle tension. With some horses, I’ll get right in there and massage the inner thighs too, my cheek resting against their derrière. I essentially hug the hip, with one arm swept in under the belly to the inside of the leg, and the other under the tail and through the legs. It’s a vulnerable position for both of us, but if the horse is receptive, I really don’t mind hanging out for a while and gently working the area.

Back to today’s session with Ebony. The rump rub was short-lived and I soon noticed that with nearly every area on his body, Ebony would stand still for 30 to 60 seconds, walk away from me, circle the stall, and re-approach in one of 3 ways,  1) with a side of his neck arched toward me, 2) with his head lowered, placing his forehead on my chest, or 3) with his head raised, presenting the underside of his jaw and neck. Once I realized the pattern, I more or less stood in one spot and let him position himself as if to say, “here, please!”. We went on like this for at least 30 minutes before he shifted my attention to his ears, an area he typically has not enjoyed having touched, according to one of the caretakers at the barn.

Even though this was not in any way a typical treatment, it was what Ebony wanted today. I was reassured that our time together had gone well when he yawned 6 or 7 times in succession while I massaged and scratched around his ears.

It may not be a glamorous shot, but this is one content horse!

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Controversial Techniques: Rollkur

I would be hard-pressed to say which of the controversial equitation techniques I find most appalling, there are many. However, I decided to look at rollkur for an assignment for one of the Equine Behaviour courses I’ve taken. It’s a topic that came up again recently in Global Perspectives in Equine Welfare because of the inherent contradictions of the practice. While to some it is obvious that the horse is in a state of distress, others associate it with grace and beauty. It is a position achieved by force with the application of excessive and prolonged pressure on the mouth to hold the horse’s head down in a hyper-flexed position, as is commonly seen is dressage.

The welfare implications include discomfort, pain, and compromised breathing and vision (McGreevy et al, 2010). It is this impaired vision that is thought to make the horse appear more responsive to the rider, as the horse is more reliant on the rider’s cues than its own senses of vision and proprioception (von Borstel et al., 2009).  

In a study of 15 horses during the conditioning phase of rollkur, a number of behaviours that are significant indicators of stress, discomfort, frustration, and conflict were recorded. The results indicate notable increases in tail-swishing, attempted bucks, crabbing, abnormal oral behaviour, ears fixed back, and head-tossing when in rollkur versus normal poll flexion. 14 of the 15 horses exhibited a distinct preference for regular poll flexion versus rollkur (von Borstel et al., 2009).

Another concern is that inducing any degree of hyperflexion is in violation of the principles of learning theory because it requires two simultaneous responses (neck flexion and deceleration) to one cue (bit pressure) (McGreevy et al., 2009).

On the advice of a former riding instructor, I purchased the book Twisted Truths of Modern Dressage: A search for a classical alternative by Philippe Karl (2014). In it, Karl presents the physical impacts of rollkur by muscle group. Here’s a brief summary:

  • The cervical ligaments undergo extreme and prolonged stretching that may lead to tearing, separation, and inflammation
  • The parotid glands are compressed and may become distorted, resulting in very painful inflammation and a loss of elasticity
  • The brachio-cephalic muscles, which connect the head to the forelegs, are extremely shortened and contracted, overloading and blocking the movement of the shoulders

Furthermore, the horse’s vision is negatively affected, with limited monocular vision to the sides and a very limited range of binocular vision at its feet. The horse is essentially moving blindly, unable to attain a full field of vision. The horse’s sense of gravity is also thought to be affected by the fixed head position.

The inability of the horse to properly sense its position through the normal tactile, visual and gravitational senses may result in balance disorders akin to seasickness. At least that’s a theory presented in this book.

Karl states “overbending, an unnatural attitude obtained by hands that are pulled backwards by various restraining devices, is a vulgar approach…and arises from a serious lack of knowledge of the horse…It is an authoritarian and brutal approach to domination that significantly deprives the horse of its capacities and places ‘man’s noblest conquest’ in the position of a slave restrained in shackles” (p. 27).

The Fédération Equestre Internationale (FEI) has effectively banned rollkur from competition and training, however, it still permits sustained flexion of the horses’ neck as long as the nose remains in front of the vertical.  It is also still acceptable to maintain a horse’s head and neck carriage in a sustained or fixed position for up to 10 minutes during training exercises (Horsetalk.co.nz, 2010).

Imagine what it would feel like to have your head held in a fixed position by 5 kilograms of force – the mean rein tension recorded in dressage to maintain a horse’s head and neck posture (International Society for Equitation Science, undated). Can any degree of forced, sustained flexion be considered ethical?

This is in direct contradiction of the main teaching of negative reinforcement training – that correct, welfare-appropriate training is achieved when pressure is released as soon as the desired response is performed. The “ability of the horse to maintain a particular head and neck posture that is appropriate for the stage of training without continuous or high rein tension, is fundamental to maintaining welfare” (International Society for Equitation Science, undated).

To do otherwise should be correctly labeled as excessive force and punishment.

 

References

Horsetalk.co.nz. (2010). “Rollkur: FEI offers hyperflexion guidelines.” Retrieved from http://www.horsetalk.co.nz/news/2010/05/081.shtml#axzz571BCD1Bj

International Society for Equitation Science. (undated). ISES position statement on alterations of the horses’ head and neck posture in equitation. Retrieved from http://equitationscience.com/file_download/141/ISES_PS_on_alterations_of_the_cervical_vertebrae_in_equitation.pdf

Karl, Philippe. (2014). Twisted Truths of Modern Dressage: A search for a classical alternative. (5th ed.). Richmond, UK: Cadmos Publishing Limited

McGreevy, P.D., Harman, A., McLean, A. & L. Hawson. (2010). “Over-flexing the horse’s neck: A modern equestrian obsession.” Journal of Veterinary Behaviour: Clinical Applications and Research. 5(4) 180-186

Von Borstel, U.U., Heatly Duncan, I.J., Shoveller, A.K., Merkies, K., Keeling, L.J., and S.T. Millman. (2009). “Impact of riding in a coercively obtained Rollkur posture on welfare and fear of performance horses.” Applied Animal Behaviour Science 116(2-4) 228-236

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By Oliver Abels

Understanding Wobbler Syndrome

Wobbler syndrome is associated with cervical stenotic myelopathy (CSM), a malformation of the vertebrae or a narrowing of the spinal canal that compresses the spinal cord, damaging nerves and affecting proprioception.  Clinical signs include gait abnormalities signified by a loss of balance, loss of coordination (ataxia), weakness, and in some cases, paresis or paralysis.

Other scientific names for the disease include cervical vertebral malformation, cervical vertebral compressive myelopathy, cervical vertebral stenotic myelopathy, and cervical vertebral stenosis.

CSM is primarily classified as a developmental or orthopedic disease and typically occurs in young horses between the ages of 4 months and 4 years of age, with a mean age of 2 for diagnosis and distinct peaks of diagnosis coinciding with periods of rapid skeletal growth around 6 months and 1.5 years of age. The prevalence of the disease in young horses is due to increased susceptibility to growth abnormalities and trauma until their skeletons fully mature and all of their growth plates close. The vertebral processes are the last part of the skeleton to mature, at between 3 and approximately 5 years of age.  CSM also affects older horses as a secondary effect of arthritis.

Causes & Pathogenesis

The causes of CSM are multifactorial and may include one or a combination of the following, a high carbohydrate diet to promote faster than normal growth rates, nutritional imbalances leading to copper deficiencies and excessive dietary zinc, instability of the vertebral column, physical trauma, osteochondrosis and osteosclerosis due to the abnormal maturation of bone and cartilage, genetics, and arthritis.

There are two theories of pathogenesis, the developmental theory and the biomechanical theory. The developmental theory proposes that cervical vertebral malformations occur in response to an underlying bone disorder that affects cartilage formation and maturation. Whereas the biomechanical theory proposes that cervical static stenosis, narrowing of the cervical canal between C5 and C7, is the result of force and mechanical stress on the cervical column which causes structural changes in the vertebrae. Mechanical stresses include strain or physical trauma from injuries, such as when a young horse is restrained with a halter and tied up for the first time, or is cast in a stall, vibration, and oscillation of the neck.

Young horses diagnosed with CSM between the ages of 4 to 18 months typically have lesions between the C3 and C5 vertebrae which compress on the spinal cord when the neck is flexed, known as dynamic compression, or cervical vertebral instability caused by abnormal movement of the cervical vertebrae. Whereas, horses between 1 to 4 years of age are more likely have a narrowing of the cervical canal, which causes static compression to occur regardless of the position of the neck due to the abnormal formation and shape of the vertebrae. In some cases, narrowing of the spinal canal may be more extensive, extending from C3 to C7. In older horses static compression and narrowing of the cervical canal is most likely the result of chronic trauma to the neck or arthritis in the cervical vertebrae.

Breed & Genetic Predisposition

While it has been reported in a variety of breeds, there is a higher incidence of the disease in rapidly growing horses, Thoroughbreds, Warmbloods, Quarter Horses, and Tennessee Walking Horses, with males being affected more frequently than females. However, there is still considerable debate regarding genetic predisposition, see Prevention below. The reasons for the gender predisposition are thought to be related to the different effects of testosterone and estrogen on growth rates. Affected horses, generally, tend to be larger males with longer necks compared to age-matched horses in control groups.

Clinical Signs & Diagnostics

Clinical signs associated with CSM include mild to progressive ataxia (loss of coordination) most often observed in the hind limbs, weakness, and in some cases paresis or paralysis. Ataxia is generally more prevalent in the hind limbs than the forelimbs because the nerves that are connected to the hindlimbs are located along the outside of the cervical area of the spinal cord and are easily damaged by any compression or trauma of the cervical spine, whereas the nerves connected to the forelimbs are located deeper within the spinal cord and thus better protected.

There is a series of preliminary tests that can be performed, preferably with a veterinarian present for safety reasons, to confirm the presence of ataxia and impaired neurological function indicative of Wobbler syndrome. These include 1) turning the horse in a small circle – a horse with CSM will swing rear legs out while turning; 2) walking the horse backwards – wobblers will have trouble backing up, hopping with the rear legs rather than in the normal two-beat fashion; 3) while one person is walking the horse forward, another person will pull the horse to one side by the tail – a wobbler will have an impaired sense of proprioception and will easily be pulled over without being able to correct its position; 4) if the horse does not exhibit any resistance to having its tail lifted, this is a good indication of nerve damage along the spinal cord.

Following a complete neurological exam, advanced diagnostics will be used to determine the specific cause of the gait abnormality and confirm whether or not cervical damage has occurred. It is also necessary to rule out other diseases that can cause ataxia, including equine protozoal myeloencephalitis, West Nile, equine herpes virus, and rabies. A definitive diagnosis depends on radiographs of the cervical vertebrae to measure the diameter of the spinal canal and, if stenosis is indicated, a myelogram will also be performed to determine the presence and extent of spinal cord compression.

Treatment & Potential Complications

Initial treatment with anti-inflammatories and corticosteroids may help minimize acute inflammation but will not have any significant long-term benefit.  Osmotic diuretics may be more effective at decreasing swelling of the nerve tissue and relieving intracranial pressure, but this too is a temporary measure.  In young horses, if caught early enough, dietary adjustments and a reduced level of exercise for an extended period of time may be an adequate level of intervention and the horse may grow out of the problem. In some mature horses, depending on the degree of ataxia, the location of compression and number of vertebrae involved, surgical fusion may be performed. The most common surgical intervention involves placing a titanium basket around the affected vertebrae to promote fusion and relieve compression on the spinal cord.  

In many cases, CSM is performance-limiting even after surgery. While Crabbe indicates approximately 70% of horses treated surgically will experience some degree of improvement, only about 50% are likely to be able to perform in athletic disciplines. Even following improvements from vertebral fusion surgery, horses may still have residual neurological problems, including mild ataxia and should be considered unsafe to ride.

Prevention

Orthopedic development of the disease may be preventable through balanced nutrition for both mare and foal to promote natural growth rates. Horse pairings that have previously produced foals with wobblers should not be bred again, as there may be a genetic predisposition. However, it has been reported that breeding trials between stallions and mares confirmed to have CSM did not produce any foals with Wobbler syndrome. More research is needed regarding the role of genetics in the development of the disease.  Preventative measures for the mature horse were not indicated in the literature.

Owner Impact

Horses with Wobbler syndrome pose a danger to themselves and others.  Severe ataxia can increase chances of traumatic self-injury and casting, and the horses may also be difficult to safely handle and/or ride. These cases have significant financial impact related to diagnostic and treatment expenses, as well as a significant emotional impact, as owners must make a decision between treatment and euthanasia. For humane reasons, it is common for horses affected by CSM to be euthanized, particularly in more advanced or severe cases, for the safety of both horse and human.

Resources

Bennett, D. (2008). “Timing and Rate of Skeletal Maturation in Horses, With Comments on Starting Young Horses and the State of the Industry.” Equine Studies Institute. Retrieved from http://www.equinestudies.org/ranger_2008/ranger_piece_2008_pdf1.pdf

Camargo, F. C. & J. Janes (2010). “Wobbler Syndrome in Horses.” University of Kentucky College of Agriculture ID-182. Retrieved from http://www2.ca.uky.edu/agcomm/pubs/id/id182/id182.pdf

Church, S.L. (2016). “Wobbler Syndrome: What’s Going on With the Neck Vertebrae?” The Horse Feb 10, 2016. Retrieved from http://www.thehorse.com/articles/37087/wobbler-syndrome-whats-going-on-with-the-neck-vertebrae

Crabbe, B. (2007). The Comprehensive Guide to Equine Veterinary Medicine. New York, NY: Sterling Publishing Co.

Finno, C. (undated). “Major Causes of Spinal Ataxia in the Horse.” University of Minnesota Horse Extension. Retrieved from http://www.extension.umn.edu/agriculture/horse/health/major-causes-of-spinal-ataxia-in-the-horse/index.html

Foreman, J.H. (2016). “Some Important Diseases of the Equine Neurological System.” University of Illinois College of Veterinary Medicine. Retrieved from http://vetmed.illinois.edu/search-results/?wpq=wobbler%20horse

Grant, B. (undated). “Equine Wobbler Syndrome.” Retrieved from http://www.equinewobblers.com/index.html

Janes, J. (2015). “Wobbler Syndrome: What We Know and Where We’re Headed.” The Horse Jul 1, 2015. Retrieved from http://www.thehorse.com/articles/36020/wobbler-syndrome-what-we-know-and-where-were-headed

Janes, J.G., Garrett, K.S., McQuerry, K.J., Waddell, S., Voor, M.J., Reed, S.M., Williams, N.M. & J.N. MacLeod. (2015). “Cervical Vertebral Lesions in Equine Stenotic Myelopathy.” Veterinary Pathology (2015) 52 (5) p. 919-927

Larson, E. (2011). “Wobbler Syndrome in Horses: An Overview.” The Horse Aug 6, 2011. Retrieved from http://www.thehorse.com/articles/27750/wobbler-syndrome-in-horses-an-overview

Levine, J.M., Ngheim, P.P., Levine, G.H., & N.D. Cohen. (2008). “Associations of sex, breed, and age with cervical vertebral compressive myelopathy in horses: 811 cases (1974-2007).” Journal of the American Veterinary Medical Association 233(9) p.1453-1458

Oswald, J., Love, S., Parkin, T.D.H., & K.J. Hughes. (2010). “Prevalence of cervical stenotic myelopathy in a population of thoroughbred horses.” Veterinary Record (2010) 166, p.82-83

Slater, J. D. & E.J. Knowles. (2012). Ch. 14: “Medical nursing.” In K.M. Coumbe (Ed.), Equine Veterinary Nursing. P.246-285 John Wiley & Sons Incorporated

 

Xenophon Continued: Notes on conformation

Xenophon describes what to look for when purchasing a horse in fairly simplistic terms when compared to the level of detail presented in Horse Conformation: Structure, Soundness, and Performance (Equine Research, 2004). However, it is evident that he had a reasonably sound understanding of the importance of form relative to function and equine health. One notable shortcoming is that in some instances, Xenophon’s focus was primarily on how conformation affects the comfort of the rider and what bearing it has on the aesthetic value of the animal. This is most evident in his descriptions of the body of the horse, the back, barrel and withers.

For example, when describing the back, Xenophon says that a double back is both “better looking” than a single back and “easier to sit upon”. Based on this description, one can only assume he is referring to a groove along the spine rather than a ridge. While this is true if riding without a saddle, it doesn’t speak to the full function of the horse’s back. The back should be relatively short, straight and wide to support the weight of the horse’s ribs, muscles and organs, as well as the weight of a rider while allowing the horse to maintain balance (Equine Research, 2004).

As for the barrel, while Xenophon understood that it should have deep sides rounded at the belly, which he interpreted as a sign of strength and a healthy appetite, he states that, as with a double back, the deep sides and round belly also make it “easier for a rider to sit on the horse”. However, he makes no mention of the importance of the depth and roundness of the barrel to accommodate and protect the horse’s large heart, lungs and other internal organs within a spacious rib cage, which should have largely-spaced backward sloping ribs to allow for full expansion of the lungs (Equine Research, 2004).

No hoof, no horse

These examples aside, Xenophon (1893) was keenly aware that the feet were of the utmost importance in determining the value of a horse, and should be examined first, for “just as a house would be good for nothing if it were very handsome above but lacked the proper foundations, so too a [horse], even if all his other points were fine, would yet be no good for nothing if he had bad feet; for he could not use a single one of his fine points” (p.14).  He recognized that the pasterns should be moderately sloping and the knees supple, and perhaps most importantly, he knew the value of healthy hoofs, with an emphasis on the thickness of the horn and the height of the walls. However, his view that the frog should be kept off the ground is somewhat erroneous, failing to recognize its role in absorbing concussive force and contributing to the horse’s sense of proprioception. The size and hardness of the frog changes in response to water content and ground contact, and plays an important role in biomechanical function and shock absorption with its ability to widen and dissipate concussive force when the heel strikes the ground (Equine Research, 2004; Hood and Larson, 2013).

Nonetheless, Xenophon’s observations continue to present a good starting point from which to evaluate the conformation of the horse, even if they do seem somewhat human-centric, and understandably so, as his descriptions were based on observations and learned experience, not informed by in-depth studies of biomechanics and kinesiology as current conformation standards are.

Xenophon vs. Equine Research

Here is a full list of Xenophon’s notes on conformation compared to the book Horse Conformation: Structure, Soundness, and Performance by Equine Research (2004).

The Art of Horsemanship (Xenophon, 1893) Horse Conformation: Structure, Soundness, and Performance (Equine Research, 2004)
Head Bony, with a small jaw, a large poll. Proportional to the size of the body, long with well defined features and ample room for the nasal passages teeth, tongue and top of the windpipe. The angle where the head meets the neck must not be too acute, otherwise it may restrict the horse’s breathing by compressing the larynx
Jaws The jaws should be symmetrical.

 

 

Strong and broad with sufficient width between the jaws to accommodate the large amount of airflow required for optimal respiration. To ensure proper grinding of food and even wear of the teeth, the jaws should meet evenly and have good up-and-down and side-to-side motions.
Eyes Prominent eyes enable the horse to see farther. Horse’s with deep-set eyes may have a slightly limited field of vision. Prominent, round eyes that are widely-spaced at the sides of the head enable horses to see nearly 360 degrees. The eyes should also be bright, clear, alert, and intelligent in appearance. Eyes that are dark brown in colour may be preferable, as blue and green eyes are more photosensitive.
Ears should be small Ears should be proportional in size to the head. If they are too long, the horse is said to have mule ears, too far apart or droopy, they are considered lopped. Either way, this is generally of minimal concern.
Muzzle Wide nostrils are necessary for the horse to breathe freely. The muzzle should be small with large, open, thin-walled nostrils to intake large volumes of oxygen. Firm, muscular lips are needed to select and grasp food.
Neck The neck should be slim and rise straight up from the chest to the poll, where it bends to reach the head. The neck, although slender, should be muscular and slightly arched along the topline, from withers to poll, with a straight underline
Withers High withers provide the rider with a “surer” seat and a stronger grip on the shoulders. Well-defined, medium high, sloping withers usually indicate longer shoulder muscles, which allow for increased extension of the forelegs and freer movement of the hindlegs. They also help keep a saddle in place.
Chest A very broad chest is not only handsome and strong, it is better adapted to carry the legs far apart from one another. Well-defined and fairly wide, without being extremely wide or overly narrow. An overly narrow chest will result in the forelegs being too close together, and too much width will cause a rolling motion when the horse is in motion. A slight pectoral bulge should be visible from the side.  
Forelegs Moderately sloping pasterns leading up to stout cannon bones and forearms. Knees that are supple in bending indicate an overall suppleness in the legs. Long, sloping shoulders, angled toward the front to meet the upper arm, which angles toward the back to meet the forearm, then straight down from the elbow to the fetlock, where the foreleg angles toward the front again through the pastern to meet the hoof. The angles of the shoulder, pastern and hoof wall should be equal to maximize shock-absorption.
Back A double back is both better looking than a single back and easier to sit upon. Based on this description, one can only assume he is referring to a groove along the spine rather than a ridge. The back should be relatively short, straight and wide to support the weight of the horse’s ribs, muscles and organs, as well as the weight of a rider while allowing the horse to maintain balance.
Loin A broad short loin makes it easier for the horse to raise his foreleg and follow with the hindquarters. The loin plays a key role in impulsion and is most effective at supporting the lumbar vertebrae and transferring power forward from the hindlegs when it is short and well developed.
Barrel Deep sides rounded at the belly indicate strength and a healthy appetite, and make it easier for a rider to sit on the horse. The barrel should be deep and wide to accommodate the horse’s large heart and expanding lungs with a spacious rib cage to protect them, along with the internal organs. Backward sloping, largely-spaced ribs allow for full expansion of the lungs.    
Hind legs Xenophon states nothing specifically about the hindlegs, and instead refers the reader to his specifications for the forelegs. Providing most of the power for locomotion, the hind legs also absorb a great deal of concussive force.  Well muscled and strong, the angles of the stifle and hock are less than those of the shoulder and upper arm. The point of buttock, point of hock, and back of the cannon should line up with one another in a straight line.  
Hind-quarters Proportional to the sides of the chest, the hindquarters should be broad and full. Appearing square and symmetrical when viewed from behind, with a rounded croup, the muscular, powerful  hindquarters play a key role in moving the horse.
Feet The horn should be thick with high walls of the hoof to keep the frog off of the ground. Well-proportioned and set squarely on the legs with rounded toes and broad heels, the feet should be balanced and symmetrical, allowing for even distribution of concussive forces.
Starting from the top
The head, neck & chest

According to Xenophon, the head should be bony, with a small jaw and large poll. Equine Research (ER) specifies that the head should be proportional to the size of the body, long with well-defined features and ample room for the nasal passages, teeth, tongue and top of the windpipe. The angle where the head meets the neck must not be too acute, otherwise it may restrict the horse’s breathing by compressing the larynx. ER describes the jaws as being strong and broad with sufficient width between them to accommodate the large amount of airflow required for optimal respiration. To ensure proper grinding of food and even wear of the teeth, the jaws should meet evenly and have good up-and-down and side-to-side motions. Whereas as Xenophon simply states that the jaws should be symmetrical. He likewise simply indicates that wide nostrils are necessary for the horse to breathe freely, which is accurate, however, that’s where his description of the muzzle ends. In addition to a small muzzle with large, open, thin-walled nostrils, firm, muscular lips are needed to select and grasp food (ER).

Horse’s with deep-set eyes may have a slightly limited field of vision, whereas prominent, round eyes that are widely-spaced at the sides of the head enable horses to see nearly 360 degrees. The eyes should also be bright, clear, alert, and intelligent in appearance (ER). Xenophon does not elaborate on what to look for in the eyes, apart from their prominent position on the head to enable the horse to see farther. Likewise, he says simply that ears should be small, whereas, according to ER, ears should be proportional in size to the head. If they are too long, the horse is said to have mule ears, too far apart or droopy, they are considered lopped. Either way, this is generally of minimal concern.

Moving down from the head, Xenophon prized a slim neck rising straight up from the chest to the poll, where it bent to reach the head. However, the neck, although slender, should be muscular and slightly arched along the topline, from withers to poll, with a straight underline (ER). At the base of the neck, the withers should be well-defined, medium high, and sloping. This indicates longer shoulder muscles, which allow for increased extension of the forelegs and freer movement of the  hindlegs. They also help keep a saddle in place (ER). This last feature is what was prized by Xenophon, as high withers provide the rider with a “surer” seat and a stronger grip on the shoulders.

Handsome and strong, Xenophon indicates that a very broad chest is better adapted to carry the horse’s legs far apart from one another. The ideal chest according to ER should be well-defined and fairly wide, without being extremely wide or overly narrow. An overly narrow chest will result in the forelegs being too close together, and too much width will cause a rolling motion when the horse is in motion. And a slight pectoral bulge should be visible from the side.  

The legs: supple & powerful

The forelegs should consist of long, sloping shoulders, angled toward the front to meet the upper arm, which angles toward the back to meet the forearm, then straight down from the elbow to the fetlock, where the foreleg angles toward the front again through the pastern to meet the hoof. The angles of the shoulder, pastern and hoof wall should be equal to maximize shock-absorption (ER). Xenophon describes the forelegs in simpler terms, with an emphasis on suppleness and moderately sloping pasterns leading up to stout cannon bones and forearms. Knees that are supple in bending indicate an overall suppleness in the legs, and refers the reader to these same specifications for the hindlegs, greatly underestimating their importance in locomotion.

Providing most of the power for locomotion, the hindlegs also absorb a great deal of concussive force.  Well muscled and strong, the angles of the stifle and hock are less than those of the shoulder and upper arm. The point of buttock, point of hock, and back of the cannon should line up with one another in a straight line (ER). Proportional to the sides of the chest, the hindquarters should be broad and full (Xenophon). Appearing square and symmetrical when viewed from behind, with a rounded croup, the muscular, powerful  hindquarters play a key role in moving the horse (ER).

The loin plays a key role in impulsion and is most effective at supporting the lumbar vertebrae and transferring power forward from the hindlegs when it is short and well developed (ER). Xenophon was definitely in tune with this, as he indicates that a broad short loin makes it easier for the horse to raise his foreleg and follow with the hindquarters.

The End.

References

Equine Research. (2004). Horse Conformation: Structure, Soundness, and Performance. Guilford CT: The Lyons Press.

Hood, D.M. and C.K. Larson. 2013. Building the Equine Hoof. Eden Prairie, Minnesota: Zinpro Corporation.

Xenophon. (1893). The Art of Horsemanship. Translated by M.H. Morgan. Boston: Little, Brown, And Company.

 

To Shoe or Not to Shoe? Part 4: Benefits of Being Barefoot

Photo: Alexandra Beckstett, The Horse Managing Editor
A Healthier Foot

Allowing a horse to go barefoot for even just part of the year can be beneficial and promote soundness. In the article “Barefoot Benefits” Gabrielle Pullen (2001) summarizes Robert Bowker’s examination of 125 barefoot horses (never shod) and 10 show horses (previously always shod) that had their shoes removed for the non-competition seasons. His findings demonstrated that when allowed to go barefoot, a horse’s feet will eventually regain characteristics associated with a “healthier” foot.

In the 10 show horses studied, conformation of the feet showed signs of change within three weeks of shoe removal, exhibiting a widening of the hooves, increased shallowness of the soles, callus formation on the toe of the soles, and a shortened breakover distance. After six to nine weeks foot width increased, the frogs became larger and had more contact with the ground, increasing the weight-bearing area of the sole and reducing stress on the hoof walls. Bowker found that “these horse’s adapted barefoot hoof characteristics [were] the same as those found in sound hooves with no internal problems” (Pullen, 2001).

Proprioception

In addition to the flexible properties of the hoof previously described, the hoof also has a significant role in the horse’s sense of proprioception. Proprioception is “the perception by an animal of stimuli relating to its own position, posture, equilibrium, or internal condition” (Encyclopedia Britannica).

Robert Bowker’s research postulates that the hoof has receptors that are similar to those that stimulate skin sensations in other species, which might explain why horse’s feet respond differently to different surfaces. If the hoof is, in fact, a sensitive and responsive organ, then altering its surface by applying shoes will likely interfere with the horse’s innate sense of proprioception (Pullen, 2001).

According to the veterinarian Tomas Teskey (2005) and the farrier Ward Edwards (2012), horseshoes significantly impair a horse’s sense of proprioception. Similar to a gloved hand, the shod hoof has dulled sensitivity and is only able to get a general feel of the surface it is in contact with. When there is a lack of sensory feedback, the horse may inadvertently pay less attention to where its feet are landing and be less surefooted. Its ability to compensate and adjust weight on uneven or slippery footing will also be inhibited, making the horse more prone to injury.

To Shoe or Not to Shoe? That is the Question

In conclusion, I’d like to reiterate a few points from Part 1.

When deciding whether or not to shoe a horse, a number of factors must be carefully considered, including the genetics and breed of the horse, individual hoof conformation, the climate the horse lives in, and the type of footing on which it works or performs. Ultimately, hoof structure is the determining factor in deciding what is best for a particular horse (O’Grady, 2007).

If a horse is in good health, has good conformation, and its hooves are properly cared for, there’s no reason for shoes or other footwear under normal circumstances. However, the case can definitely be made to shoe a horse for therapeutic or work/performance purposes. Each horse must be considered individually. It is unreasonable to think that all horses must be shod, or conversely, that all horses should be barefoot.

References

Edwards, W. (2012). “Barefoot Benefits.” Farrier Service Plus: Whole Horse Farriery. Retrieved from http://www.farrierserviceplus.com/tag/proprioception/

Encyclopedia Britannica. “Proprioception.” Retrieved from https://www.britannica.com/science/proprioception

O’Grady, S. (2007). “Barefoot vs. Shod? It depends…” Virginia Therapeutic Farriery. Originally published in American Farriers Journal Jan/Feb 2007. Retrieved from http://www.equipodiatry.com/article_barefoot_v_shod.htm

Pullen, G. (2001). “Barefoot Benefits.” The Horse Jul 1, 2001. Retrieved from http://www.thehorse.com/articles/10855/barefoot-benefits

Teskey, T. (2005). “The Unfettered Foot” A Paradigm Change for Equine Podiatry.” Journal of Equine Veterinary Science 25(2) (2005) 77-83

To Shoe or Not to Shoe? Part 3: The Shod Horse

Photo credit: David Goldman, Associated Press
Performance and Therapy

Despite the hoof being a very resilient and adaptive structure, horses engaging in strenuous performance sports often require shoes for extra support, protection to preserve the hoof capsule and structures contained within it, and traction for the safety of both horse and rider (Bryant, 1999). Horseshoes can be shaped to compensate for hoof irregularities while offering support to the feet and legs and protecting the toe of the hoof from wear. The majority of shoes remain open at the heel to allow for the natural flexion and expansion of the hoof when it comes into contact with the ground, leaving the frog and sole uncovered because of their important role in shock absorption (Bryant, 1999; O’Grady, 2008).

A variety of shoeing materials and styles are used based on the discipline in which the horse performs, the breed and natural conformation of the horse, and the ground surface it performs on. For example, Thoroughbreds are shod with very thin aluminum shoes called racing plates, whereas hunters wear much thicker, but still lightweight, aluminum shoes. In contrast, high-stepping horses like the Tennessee Walker are often (controversially) outfitted with weighted shoes and pads on hooves with an extra long toe and disproportionately short heel to exaggerate their natural gait, as the heavier shoe forces the horse to heighten its step (Bryant, 1999; Montgomery, 2014).

For therapeutic purposes, shoes can be used to provide additional heel support to horses that have low heels, treat cases of laminitis and navicular disease, and repair quarter cracks by shifting the weight distribution on the hoof wall (Bryant, 1999).

The Farriers Role

The role of the farrier is to maintain and promote a healthy hoof wall, an appropriate sole depth, and soft tissue structures of a sufficient mass to properly support the bones, tendons, and ligaments within the hoof (O’Grady, 2007). There are three main forces that are altered by farriery – independent of the application of shoes – and play a role in foot pathology and therapy. These are 1) ground reaction force – the upward force of the ground on the hoof; 2) the force of the horse’s weight transmitted downward through the limb; and 3) the upward pull of the deep digital flexor tendon (Corp-Minamiji, 2015).

Once the hoof has been evenly trimmed and balanced by the farrier, a variety of shoes can be applied for performance and therapeutic purposes. The following list highlights those that are used in therapy (Bryant, 1999; Corp-Minamiji, 2015; O’Grady, 2008).

  1. Straight bar shoes provide extra heel support for damaged or under-run heels and stabilize the downward pressure of the foot, creating an evener distribution of weight.
  2. In feet with well-developed frogs, the heart-bar shoe may be used. This shoe covers the frog and transfers some of the weight from the wall of the hoof to the soft tissues, which can be helpful in treating cases of laminitis and quarter cracks.
  3. The oval egg-bar covers the back portion of the hoof to offer extra support for horses with low heels.
  4. The practice of wedging with pads and/or rails applied to the shoe shifts the forces on the foot and affects the position of the coffin joint, which can be beneficial for horses that have advanced cases of laminitis with coffin bone rotation.
  5. Wooden shoes cut from plywood are strictly used for therapeutic purposes, easing breakover and decreasing force on the lamella.  
  6. Glue-on shoes can be used on horses to eliminate the need for nails in cases where the horse has poor-quality feet but requires shoes for a short time.

Under the right circumstances, horseshoes can be highly beneficial to the health, comfort, and conformation of a horse, however, not all shoes are created equal. For example, O’Grady (2008) indicates that egg-bar and other bar-type shoes increase concussive forces from hard surfaces, and Ovnicek (2003) believes that “conventional shoes (non-orthopedic) can stand in the way of the hoof’s natural function”.

A Few Problems with Horseshoes

“Horseshoes are a necessary evil!” say some (Pullen, 2001). “Forcing the flexible hoof to function when restricted by a rigid, steel shoe is a powerful prescription for promoting the hoof’s deterioration”, says Tomas Teskey (2005), one of the more vocal critics.

The hoof is a flexible structure designed to expand and contract in response to the ground surface (footing), moisture and concussive force. The natural response of the hoof is to flex outward 2 to 4 millimeters when it is bearing weight. The degree of flexion is in response to the hardness of the footing. When shod this movement is impeded and the hoof is not able to function as it normally would. “If you draw a chalk line around the foot of a shod horse standing on hard ground, then do the same thing 15 minutes after the shoe has been pulled, you will find that the foot has expanded beyond the original line” (Pullen, 2001).

Furthermore, when a horse is shod, the majority of its weight is loaded onto the perimeter of the hoof wall. According to Robert Bowker, “only a small percentage of the load should be on the hoof wall, with the sole, frog, and bars bearing the majority” of the force, which will strengthen the foot and reduce the concussive force transmitted to the bone through connective tissues (DeFee Mendik, 2016).

Improperly fitted shoes can also cause a variety of problems, including hoof cracks, low heels, and sheared heels. Sheared heels are caused by uneven heel trimming in shod horses but are rare in barefoot horses because the taller heel is naturally worn down (Equine Research, 2004).

References

Bryant, J. (1999). “A Footwear Primer.” The Horse. Retrieved from www.thehorse.com/articles/10364/a-footwearprimer

Corp-Minamiji, C. (2015). “Therapeutic Shoeing Part 2: Hardware and Healing.” The Horse. Retrieved from www.thehorse.com/articles/28437/therapeutic-shoeing-part-2-hardware-and-healing

DeFee Mendik, N. (2016) “Back to Barefoot.” The Horse. Retrieved from http://www.thehorse.com/articles/31022/back-to-barefoot

Equine Research. (2004). Horse Conformation: Structure, Soundness, and Performance. Guilford, Connecticut: The Lyons Press.

Montgomery, M. (2014). “Exposed! Tennessee Walking Horse Celebration: Celebrating Cruelty?” One Green Planet. Retrieved from www.onegreenplanet.org/animalsandnature/exposed-tennessee-walking-horse-celebration-celebrating-cruelty

O’Grady, S. (2007). “Barefoot vs. Shod? It depends…” Virginia Therapeutic Farriery. Originally published in American Farriers Journal Jan/Feb 2007. Retrieved from http://www.equipodiatry.com/article_barefoot_v_shod.htm

O’Grady, S. (2008). “Basic Farriery for the Performance Horse.” Veterinary Clinics: Equine Practice vol. 24 (2008) 203-218

Ovnicek, G. et al. (2003). “Natural balance trimming and shoeing: its theory and application.” Vet Clin Equine 19 (2003) 353-377

Pullen, G. (2001). “Barefoot Benefits.” The Horse. Retrieved from http://www.thehorse.com/articles/10855/barefoot-benefits

Teskey, T. (2005). “The Unfettered Foot” A Paradigm Change for Equine Podiatry.” Journal of Equine Veterinary Science 25(2) (2005) 77-83

To Shoe or Not to Shoe? Part 2: The Horn of Plenty

An intricate and complicated host of tissues, blood vessels, tendons, ligaments and bones comprise the [horse’s] foot, and the whole package is sealed within a hard, horny shell – the hoof wall. – Lester Sellnow, 2001

Image: Anatomy of a Healthy Hoof, Animal Health Trust
Structure of the Hoof

The hoof has evolved to serve a number of important functions for the horse, including supporting an incredible amount of weight, absorbing shock, providing traction and conducting moisture. The hoof wall is essentially a self-replenishing keratinized horn. More specifically, it is a series of keratinized cells arranged in parallel tubules that run perpendicular from the coronary band at the top to the bottom surface of the wall. The outermost layer that forms the hoof wall begins at the coronet, the band separating the skin of the lower leg from the hoof, and is composed of the stratum externum (periople) and the stratum tectorium (Hood & Larson, 2013; Sellnow 2001).

The periople is similar to the cuticle of the human fingernail. It protects the junction between the horn and the skin, and extends less than ¾ of an inch down from the coronary band around the entire hoof, and to the bulbs of the heels at the back. The bulbs are the most flexible part of the hoof, allowing the foot to change shape in response to weight-bearing forces upon ground contact. The stratum tectorium is a thin shiny layer similar to the human fingernail. It gives the hoof a glossy appearance and helps retain moisture (Equine Research, 2004; Hood & Larson, 2013; Sellnow, 2001).

The stratum medium, the middle layer of the hoof wall, is the densest portion of the hoof, and as such, bears most of the weight of the horse. This layer consists of two zones. The outer zone is quite rigid and serves as a barrier between the foot and the external environment, while the inner zone is quite flexible and elastic, contributing to the hoof capsule’s ability to change shape in response to force. The innermost part of the hoof wall is the stratum internum (insensitive laminar layer). It consists of hundreds of alternating epidermal and dermal folds called laminae. Approximately 600 insensitive primary laminae project from the inside surface of the hoof wall, each one branching off into secondary and tertiary laminae. The laminae secure the coffin bone and attach it to the hoof wall  (Hood & Larson, 2013).

The solar surface of the hoof is directly exposed to the ground. Its main function is to support the internal weight of the foot and dissipate concussive forces in the leg. In most domestic horses the outer wall is the primary weight-bearing structure, while the sole takes on more of this role on softer footing. Other sections of the solar surface that come into contact with the ground are the heels, frog, and bars, with the heels being the first part of the foot to make contact when the horse is in motion. The size and hardness of the frog changes in response to water content and ground contact, and plays an important role in biomechanical function and shock absorption with its ability to widen and dissipate concussive force when the heel strikes the ground. The bars are thought to act as a spring, adding to the biomechanical forces that simultaneously cause the hoof to flatten and the heels to expand  (Equine Research, 2004; Hood & Larson, 2013).

The Feral Hoof

The hooves of feral and domestic horses are not the same. They differ vastly in shape, look and feel. Horse’s hooves have developed over thousands of years to adapt to a range of ground conditions, and the hooves of feral horses are shaped by their environment. Even though some feral horses tend to have a ‘conventional’ looking hoof shape that has been used as a model for domestic hoof care, the way in which the hoof capsule functions and interacts with the ground is in sharp contrast to the way the hooves of domestic horses are typically managed, and should not be readily adopted.

In contrast to the domestic horse, feral horses have thicker, stronger hoof walls that sometimes become rounded and have little to no ground contact. In many cases, particularly for horses living in dry conditions with hard footing, the sole has more contact with the ground than does the hoof wall. This ground contact of the sole changes the shape and function of the frog, which becomes much larger. In the words of Gene Ovnicek, the soles of feral horses are “calloused and the frog like a patch of leather” (Jurga, 2001). Robert Bowker has discovered similar findings, indicating that for the most part feral horses bear “their weight on their soles and frogs, which [are] enormous compared to the frogs of domestic horses” (Jurga, 2001).

At the opposite end of the spectrum, the hooves of horses living in sandy environments tend to develop spike-like hooks on their heels, which are present to a lesser degree on horses living in prairie, sod or gravel environments. In any of these softer conditions, horses are prone to hoof growth rates that exceed natural wear, resulting in a longer, flared hoof capsule (Jurga, 2001; Ovnicek, 2003).

Brian Hampson and Chris Pollitt (2011) elaborate that the balance between hoof capsule wear and growth rate in horses living in environments with hard footing results in a short hoof capsule that is worn to the level of the peripheral sole, leading to the sole bearing a significant portion of the horse’s weight. It is this hoof shape that has been promoted as being an ideal model for the domestic horse. However, Hampson and Pollitt believe this is actually detrimental to foot health, as indicated by the high incidence of laminitis and other foot pathologies in the horses they have studied.

The majority of the feral hooves studied by Hampson and Pollitt (this included 14 separate studies with horses ranging in number from 12 to 100 per group) showed extremely high incidences of pathology, ranging from less severe abnormalities like hoof wall cracks, flares, imbalances, narrow and uneven heels, to more serious abnormalities in the horses living in hard, rocky or desert environments, like concussive laminitis, rotated coffin bones, excessive hoof wall thickness, and ungual cartilage calcification (sidebone).

Basically, although the hooves of feral horses look robust and have been naturally modified to withstand locomotion in their respective environments, there are many negative pathologies, which, somehow, the horses are able to live with and continue to thrive under natural and sometimes harsh conditions (Hampson & Pollitt, 2011).

The “feral” or “natural” hoof, although touted by some based on the strength and durability of the hooves of feral horses living in hard, rocky environments, is not suitable for domestic horses because a) they do not wear their hooves enough naturally to maintain a healthy hoof length, and b) while the hooves of feral horses are “self-trimmed” because of distances travelled for food and water, they do have a high incidence of foot pathology.  In the case of domestic horses, whether the hoof is shod or bare, the skills and knowledge of a good farrier are essential to maintaining healthy, balanced feet.

References

Animal Health Trust. “Learn About Laminitis.” Retrieved from http://www.aht.org.uk/cms-display/cal_laminitis.html

Hampson, B.A. & C.C. Pollitt. (2011). Improving the Foot Health of the Domestic Horse: The relevance of the feral horse foot model. Australian Government, Rural Industries Research and Development Corporation: RIRDC Publication No. 11/140, RIRDC Project No. PRJ-002510. November 2011

Equine Research. (2004). Horse Conformation: Structure, Soundness, and Performance. Guilford, Connecticut: The Lyons Press.

Hood, D.M. & C.K. Larson. (2013). Building the Equine Hoof. Eden Prairie, Minnesota: Zinpro Corporation.

Jurga, F. (2001). “The Natural Hoof – A Sign of the Times.” The Horse Oct. 10, 2001. Retrieved from http://www.thehorse.com/articles/10671/the-natural-hoof-a-sign-of-the-times

Ovnicek, G. et al. (2003). “Natural balance trimming and shoeing: its theory and application.” Vet Clin Equine 19 (2003) 353-377

Sellnow, L. (2001). “The Equine Foot – Form and Function.” The Horse Oct 15, 2001. Retrieved from http://www.thehorse.com/articles/10753/the-equine-foot-form-and-function