Chiropractic: Modality of Movement

Chiropractors have been treating human patients on a professional basis in this country since before the turn of the century, but it has only been in recent years that this alternative form of therapy has been applied to a substantial number of horses and other animals.

The word chiropractic is derived from the Greek words cheir meaning "hand" and praktike meaning "business or to practice." Thus chiropractic literally means to use the hands to diagnose, treat, and prevent disease. Chiropractors use specific, controlled forces or thrusts applied by their hands or with an instrument to a joint or bone to cause a change in joints, muscles, or nerve reflexes.

Perhaps the earliest form of chiropractic adjustment involved Orientals who were skilled in walking on an individual's back with bare feet. In this country, the "father" of the modality was Dr. D. D. Palmer, who back in 1895 gave his first adjustment to a patient. Convinced that there was a need for this form of treatment, he established the Palmer College of Chiropractic and began teaching students how to apply his methods.

Through the years, chiropractors involved in treating humans also plied their craft on animals, but it was not a widely accepted practice in the veterinary community. In recent years, that has changed, as an increasing number of chiropractors are using the modality both to treat and diagnose animal ailments. This is especially true in the equine community.

Need For Education

The demand for chiropractors trained in diagnosing and treating animals resulted in the birth of a school that teaches the chiropractic approach. It is Options For Animals and is located in Hillsdale, Ill. Established in 1989 by Sharon Willoughby, DVM, DC, the school offers a 150-hour course for licensed veterinarians and chiropractors.

Though started as a school that functioned on a part-time basis, enrollment levels have increased to the point where today it operates on an ongoing schedule with an average of 60 students in each class or module.

The school, says Leslie Collins, executive manager, attracts students from all geographic areas of the United States as well as Canada and other countries.

Also offered at Options For Animals is a post-graduate course of 180 hours. Enrollment is limited to students who have completed the 150-hour course. The post-graduate course is offered in three segments, with one segment being available per year. Thus, three years would be involved in completing post-graduate work.

The emphasis at the school is on horses and dogs. Hands-on lab sessions are conducted on horses owned by the school and on dogs normally furnished by support staff. The school does not officially certify graduates as approved animal chiropractors. Instead, the student must first finish the course and pass a written examination. Then, three case studies must be completed by the student and submitted to the American Veterinary Chiropractic Association (AVCA), which is also located in Hillsdale. If the case studies meet with association approval, the student is officially certified by the AVCA.

Veterinarians and chiropractors who graduate from the school and are approved by the AVCA--it is the only one in the country that offers the 150-hour course--are ready to enter the field to use their expertise in both diagnosis and treatment.

Unfortunately, says Kevin Haussler, DVM, DC, a post-graduate researcher, Veterinary Orthopedic Research Laboratory, Department of Anatomy, Physiology and Cell Biology at the School of Veterinary Medicine, University of California, Davis, these are not the only individuals practicing a form of chiropractic in the equine community.

There are, he says, untrained individuals in the field who pass themselves off as chiropractic experts and use everything from rubber mallets and two-by-fours, to stretching a horse between two tractors, in efforts to effect "cures."

Not only do they often harm the animal, he says, but they also denigrate a valuable form of alternative therapy for horses.

To understand the principles and theories behind chiropractic, a brief overview of anatomy of the horse's back needs to be discussed.

Anatomy of the Back

"The horse's spinal column," says Haussler, "has between 51 and 57 individual vertebrae. The typical vertebra consists of a vertebral body and several vertebral processes. The vertebrae protect the spinal cord and nerves. As the nerves exit the spine, they divide into various branches. Some branches go to the joints, muscles, and skin of the back.

"Nerves can sense pain and joint movement. Pain sensors are found in the bones, joints, muscles, ligaments, and blood vessels of the back. The muscles of the head and neck can be categorized into superficial and deep muscle groups. The large, superficial back muscles span large regions of the spine and ensure coordinated back movements. The smaller, deep back muscles connect one or two vertebrae and act to move or stabilize individual vertebrae. The spinal ligaments connect the individual vertebrae and provide joint support.

"The amount and direction of spinal movement is determined mostly by joint size and shape," he says. "The neck and tail are the most mobile regions of the horse's spine. Limited back movement occurs in up and down motion, side-to-side motion, and rotation. Dressage requires a lot of spinal movement and strength. Jumping high fences requires rotation of the back and hind limbs for proper gait and clearance of fences."

When a horse loses its normal range of joint motion, says Joyce Harman, DVM, MRCVS, a practitioner in northern Virginia who utilizes both chiropractic and acupuncture in treating equines, it cannot perform appropriately.

"Chiropractic," she says "is a science that considers horses as an integrated animal. The treatment is focused on the spinal biomechanics--the musculoskeletal, neurological, and vascular relationships. The word that causes the most confusion when chiropractic is discussed in veterinary medical circles is subluxation. The traditional veterinary definition is an incomplete or partial dislocation, less than a luxation. However, the modern chiropractic definition is the alteration of the normal dynamics, an atomical physiological relationship of contiguous articular surfaces. In other words, the loss of normal motion between two bones."

When there is a loss of normal motion between two vertebrae, she further explains, there is a decrease in the normal pumping action of intervertebral discs, leading to faster aging of discs.

"Nerves become irritated at the intervertebral foramen causing aberrant neural activity. The ligaments and muscles become scarred and thickened, producing pain and muscle spasm in the surrounding area."

To return the joints to normal motion and to alleviate the pain and muscle spasms, the chiropractor performs an adjustment on the area of the spine affected.

A chiropractor, says Harman, does not work on the entire spine of a horse in one fell swoop during an adjustment. Because of the size of the animal, she says, that would be virtually impossible. "I only work on two bones (one joint) at a time."

A chiropractic adjustment, she explains, is a short-lever, specific, high-velocity, controlled thrust by a hand or instrument which is directed at a specific articulation.

"An instrument sometimes used," she says, "is called an activator, which looks like a small metal syringe and delivers a precise, rapid force to a very specific area. The techniques for these adjustments are worked out scientifically, taking into account the biomechanics and physics of the joints."

The non-educated person practicing chiropractic, Harman says, often uses "manipulation" in an effort to give an adjustment. Manipulation, she explains, is a term used to describe forceful passive movements of a joint beyond its active range of motion, such as pulling on the animal's neck.

"Manipulations are often very violent," she says, "and are the reasons many veterinarians are rightfully skeptical about chiropractic. Most veterinarians have heard horror stories about chiropractic or have had to repair the damage done when a manipulation overtly damaged a joint, as in the example of a ruptured round ligament in the coxofemoral joint (hip joint)."

A complete chiropractic examination, says Harman, includes a case history, posture analysis, gait analysis (including a lameness examination, if needed), static palpation of the spine, motion palpation of the joints, muscle palpation, and checking for any differences in temperature over the spine.

In general, she says, most practitioners will expect to treat a horse once a week for up to four weeks, then preventively once a month if the horse is competing or is very active. However, she adds, there is variation in treatment frequency depending on the severity of the problem.

Many performance horses, she says, are asked on a daily basis to twist, turn, jump, and stop--activities that create muscle tension and jar their backs and spines. These activities can result in a disruption of normal motion of vertebrae.

The goal, she says, is to restore normal motion before symptoms (signs) of such loss of motion appear. Following the onset symptoms, she says, is degeneration. Regular treatments of active horses can, she maintains, often nip a potential problem in the bud, before it ever reaches the symptom stage and well in advance of degeneration.

Much of Harman's practice involves sport horses. Chiropractic, she says, "forms the basis for everything I do with performance problems."

Her clientele ranges from Olympic level competitors to backyard pleasure horses. One of her patients was a Grand Prix level jumper which could only travel and jump in a straight line because of stiffness in the neck.

She was called to treat the horse and was pleasantly surprised to find that a single adjustment alleviated the problem.

There are a wide variety of reasons for loss of normal motion in addition to an active performance regimen, Harman says. They range from something as simple as an ill-fitting saddle to illness. In between are such causes as trauma in the pasture, accidents in the stall, confinement, pulling back in crossties, poor riding techniques, training devices, racing (with its extreme stress on the entire body), minimal warm-up time, fast starts (especially if the horse is off-balance), ponying, hot walkers, traumatic or difficult birth (especially assisted births), poor conformation, and the horse not suited to the work being asked.

Poor shoeing is also frequently involved, she says.

"Think what it would be like if we had to walk all day in a pair of uneven shoes. It would be extremely uncomfortable to our back. Yet, we ask horses to do this all the time."

Help With Lameness?

Chiropractic, Haussler believes, offers important assistance to veterinarians dealing with lameness problems. The key, he explains, is to find the primary source of pain, rather than merely treating what might be a secondary source.

He uses the analogy of a stubbed toe to explain his point. It goes something like this: If one gets out of bed in the middle of the night and severely stubs a toe, one is going to be immediately aware of primary pain. During the next few days, this may cause the injured person to walk in an abnormal manner, creating muscle tension and stress in the back and neck. After several days, the primary pain from the stubbed toe will have disappeared, but the secondary pain from tense muscles might remain.

So it is with horses.

In equine practice, says Haussler, back problems and leg injuries are often inter-related.

"Examples of this relationship," he says, "are an acute or chronic lower limb injury causing the horse to carry the affected leg abnormally. The abnormal weight bearing and altered gait can subsequently overwork or injure the associated neck or back muscles. Back injuries can, in turn, cause increased forces, lameness, or gait alteration in the feet and legs as the horse tries to protect its sore back.

"The problem facing a veterinarian is to decide whether it is the leg injury or the back injury that is the primary or initial cause of the horse's lameness. Unless the primary cause of the back pain is identified and treated, most horses will have recurring back pain when returned to work after a period of rest or trial of medications.

"Chiropractic provides additional diagnostic and therapeutic means that may assist the equine veterinarian to identify and treat the primary cause of lameness or poor performance," Haussler contends. "Specialized training in the evaluation and conservative treatment (i.e., no drugs or surgery) of back problems places chiropractors in the forefront of treatment of back-related problems. Equine chiropractic is an additional modality in veterinary medicine that can be utilized for diagnosis, treatment, and potential prevention of selected muscle or joint disorders in the horse."

Addressing Chiropractic Myths

Haussler joins Harman in clearing up some myths about what chiropractors actually do when giving an adjustment. Terms such as "out of alignment" or "my back popped out of place," he says, do not accurately describe what happens along the spine of a human or a horse.

"If a bone in your back were truly out of place," he says, "you would need surgery, not treatment by a chiropractor."

While there is movement within the joints, he explains, it is minute and this means that movement affected by the chiropractor is also minute.

Another myth. The popping sound during an adjustment is not the noise made by bones snapping back into place. A cracking or popping sound is often heard during chiropractic adjusting, says Haussler, as the joint is lightly stretched and a pocket of air forms inside the joint.

How, one might logically wonder, can a human give an adjustment to a 1,200-pound horse.

"There is a fallacy," says Haussler, "that chiropractic requires great strength. It does not. An 80-pound chiropractor could give an adjustment to a 2,000-pound rhino in the Toledo zoo. It's finesse, not strength, that's required."

The key in dealing with horses, he says, is to obtain their confidence, which, in turn, causes them to relax. It is virtually impossible, he says, to give an adjustment to a horse which is upset and refuses to stand quietly.

The secret in properly effecting the adjustment itself, he says, is to work on one joint at a time. "A 1,000-pound horse outweighs me, but I outweigh one of its joints."

Haussler went on to explain that the principle common to all chiropractic theories "is that joint fixation affects the normal nerve balance found in healthy individuals. Injury or changes in the vertebrae may cause incoordination, muscle spasms, or altered joint function."

Thus, the role played by the chiropractor during an adjustment is to return the joint to its normal status.

"Veterinary medicine," says Haussler, "is faced with some limitations when dealing with animals that have no obvious localized pain or have a vague, unspecified lameness. Chiropractic provides expertise in the evaluation of joint and back problems that can provide an additional means of diagnosis and early treatment options in certain types of lameness problems, especially conservative treatment of mechanically related musculoskeletal disorders.

"Chiropractors are also trained in the use of physiotherapy techniques, such as heating and cooling modalities, muscle stimulation, TENS (a form of electrically induced pain relief), and therapeutic ultrasound. Strength training exercises, massage, stretching techniques, and other forms of rehabilitation are also used."

Both Harman and Haussler are of the opinion that chiropractic is here to stay as a valid treatment modality. Haussler looks forward to the day when courses on this form of alternative therapy are offered in colleges of veterinary medicine. Already, he says, persons trained in chiropractic are being asked to give seminars and lectures to veterinary students in some colleges.

Chiropractic, he concludes, is not a cure-all, but is a valid treatment procedure for many back and lameness problems.


AVMA Guidelines For Veterinary Chiropractic

Veterinary chiropractic is the examination, diagnosis, and treatment of nonhuman animals through manipulation and adjustments of specific joints and cranial sutures. The term "veterinary chiropractic" should not be interpreted to include dispensing medications, performing surgery, injecting medications, recommending supplements, or replacing traditional veterinary care. While sufficient research exists documenting efficacy of chiropractic in humans, research in veterinary chiropractic is limited. Sufficient clinical and anecdotal evidence exists to indicate that veterinary chiropractic can be beneficial. It is recommended that further research be conducted in veterinary chiropractic to evaluate efficacy, indications, and limitations. The assurance of education in veterinary chiropractic is central to the ability of the veterinary profession to provide this service. Veterinary chiropractic should be performed by licensed veterinarians; however, at this time, some areas of the country do not have an adequate supply of veterinarians educated in veterinary chiropractic. Therefore, it is recommended that, where the state's practice acts permit, licensed chiropractors educated in veterinary chiropractic be allowed to practice this modality under the supervision of, or referral by, a licensed veterinarian who is providing concurrent care.


 Chiropractic--Not Yet The Complete Panacea?

Most people who work with horses would agree that back problems are a major cause of poor performance. For veterinarians this is an area that, despite the dearth of scientific information, can at times be intriguing, frequently perplexing, and often frustrating. It has certainly kept me occupied over the last 25 years. For this reason I was pleased to see Les Sellnow's article on the application of chiropractic to horses. This is, of course, a very controversial area, but he presents it in a much more balanced way than I have seen before.

I have met both Drs. Harman and Haussler and can attest to their credentials, motivation, and experience in this form of physiotherapy. I wholeheartedly agree with their holistic approach to impaired performance and back problems. However, I am not convinced that competition horses require to be continually tweaked and manipulated to keep them in peak performance.

There are a number of other points that concern me. It is clear that chiropractic involves the "potential" rather than "real" movement of joints when manipulated in the appropriate fashion. However, in parts of the back behind the saddle (i.e., lumbar and sacral regions), I do not believe that even in chiropractic terms any movement by manual manipulation is possible.

The anatomical structure of intervertebral discs in the thoracolumbar spine of the horse is very different from those in ourselves and dogs. In my experience, the intervertebral discs in horses do not significantly contribute to back problems. Neither have I been able to confirm that nerves become irritated at the intervertebral faramina causing aberrant neural activity. If there is evidence for this, I should like to see it.

I certainly do subscribe to the concept that the soft tissue structures supporting the spine (i.e., epaxial muscles and ligaments) frequently become damaged and this results in pain and muscle spasm. I see this as one of the major causes of back troubles in horses. It seems to me that the crux of chiropractic and a good deal of the other forms of physiotherapy is to release muscle spasm/tension by causing relaxation. The rest of the healing process is up to the animal. Physiotherapy is, after all, not a cure all, but a means of assisting the body's natural ability to heal itself. Something that healthy horses are very good at doing!

I am not too sure why repeated or long courses of treatment are necessary. By all accounts, there is nowadays considerable interest and involvement in chiropractic for treatment of animals, and it also appears that it can even be used in diagnosis. Nevertheless, despite all this activity, there have been no scientific reports or results of controlled clinical trials on the mode of action or efficiency of chiropractic in horses. I am keen to believe that it is a useful tool in equine practice, but would really like to see some hard evidence.

Furthermore, how does chiropractic differ from the various forms of massage and muscle stimulation currently in use? Why is it necessary to use other forms of physiotherapy in conjunction with chiropractic? In my clinical experience as a veterinarian, the greatest challenge is in "diagnosis." Something in regard to backs we are not always very good at. Dr. Haussler has said there can be knock-on effects from limb problems and lameness putting increased stress on the back leading to pain and stiffness. Management of these cases presents a very different problem from those where the pain originates in the spine. This is where my other criticism of chiropractic comes in, which is the apparent ability to alleviate pain.

I do not dispute the theory that relaxation reduces the pain. What I do question is our ability to precisely define or quantitate back pain in horses. Without this ability, how can you evaluate the success of chiropractic? The usual answer to this is that the animal being more relaxed improves in its performance. In my experience, there are many reasons for this and spontaneous recovery (as in man) is common.

We need to develop a system to precisely evaluate the degree of pain in horses and therefore to be confident of the results of a treatment. As I said at the outset, I do not wish to discredit the use of chiropractic in horses, particularly by properly qualified proponents, but I shall remain a "non-believer" until more evidence to substantiate its claims are produced.

Editor's Note: This series on alternative and complementary veterinary medicine is meant to offer basic information on the history of the therapy, what the therapy is, and how it is being used in the equine industry. Information presented in this series is not intended to promote use of the therapy; simply to offer an objective primer of how it is being applied to horses. We also offer a differing viewpoint in a sidebar entitled "Across The Fence," kind of a friendly neighbor offering a differing opinion. Owners and managers always should discuss their animals' health problems with their veterinarian before using any therapies or medications.

About the Author

Les Sellnow

Les Sellnow is a free-lance writer based near Riverton, Wyo. He specializes in articles on equine research, and operates a ranch where he raises horses and livestock. He has authored several fiction and non-fiction books, including Understanding Equine Lameness and Understanding The Young Horse, published by Eclipse Press and available at or by calling 800/582-5604.

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