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Assessing the strasser method
Equine Foot Science Assessing the Strasser Method: The Perspective of Two Farriers at Referral Veterinary Hospitals Laura Florence BFA, CFa and Patrick Reillyb
T
hroughout much of the United States, conversations of the management of horse’s hooves have revolved around a recent phenomenon and technique known as the Strasser method. Many farriers, veterinarians, and, perhaps most important and surprising, horse owners have developed forceful opinions describing this approach to caring for the equine hoof. Advertisements in horse publications such as the Northeast Equine Journal (Northeast Equine J 15;7:127) advocate that owners learn to care for their animal’s feet themselves, with the aid of a weekend course. Although this may sound like a fad that will be quick to pass, advocates of the Strasser method forcefully expound on the positive effects of this barefoot trimming system. As professionals looking to provide the best care to our clients, what are we to make of this new system? How, and in what instances, should we be incorporating Dr. Strasser’s ideas, or when are they contraindicated?
What Is the Strasser Method? Dr. Hiltrud Strasser, DVM, of Germany presents a holistic view of horse care that admonishes against keeping horses in box stalls for any period, feeding on controlled schedules with no variation in types of feed or vegetation, not allowing for free movement and herd life. Such management, according to Strasser, leads to lameness and can only be rectified by adopting a more natural lifestyle as defined in her book A Lifetime of Soundness. Arguably, her more controversial concepts are directed toward the trimming and shoeing of horses. Strasser’s prescriptive trim deviates significantly from conventional horseshoeing practices. She proposes that horseshoes are detrimental to the horse and should never be used.1
From the University of Pennsylvania School of Veterinary Medicine, New Bolton Centera Kennett Square, Pennsylvania; and Rochester Equine Clinicb, Rochester, New Hampshire Copyright © 2003, Elsevier Inc. All rights reserved 0737-0806/03/2311-0012 $30.00/0 doi:10.1053/j.jevs.2003.10.012
502
Strasser claims her method will eliminate all lameness problems and restore natural function to the afflicted horse.1 Further, she maintains that these problems can be reversed or totally avoided by keeping horses unshod and trimming according to her suggestions.1 This article will examine these aspects of the Strasser method and evaluate them according to the available literature and research.
The Strasser Trim The particular elements of the Strasser trim are well described in her book. The ideal Strasser hoof is broad, with the heels, bulbs, and frog in full contact with the ground, thus supporting the horse and promoting the proper function of the foot. She maintains that the solar surface of the distal phalanx is parallel to the ground surface and that feet should be trimmed to accomplish this positioning. She describes the hairline as having a 30-degree angle when viewed laterally, with a heel height of 3 cm. The hoof should be trimmed to about a 45-degree angle on the front feet and a 55-degree angle on the hind feet.1 The bars are to be trimmed to 1 cm height shorter than the hoof wall and the sole pared from the apex of the frog back to the heels, creating a more concave shape and pliable thinness intended to allow for hoof expansion.1 Dr. Strasser believes this to be the most natural positioning for the distal limb and one that creates optimum health for the horse.
No Shoes The Strasser method rejects the use of horseshoes, stating that they are an “anesthetizing crutch”.1 She maintains that lameness is the result of keeping horses shod and can be reversed or avoided by keeping horses barefoot and trimmed according to her specifications.1 The basic thought process behind Strasser’s opposition to shoes is as follows: shoes interfere with the natural function of the hoof, which leads to a reduction of the neurologic sensations of the hoof. The mechanical interference from the shoe leads to diminished circulation of the hoof.1 Loss of circulation leads to poor-quality hoof
Journal of Equine Veterinary Science
November 2003
Table 1
Strasser advocated values Rochester Equine Clinic*
Dorsal wall angle (front Feet)
Hair line angle
Heel height
45 degrees
30 degrees
3.0 cm
52.38 degrees
23.31 degrees
2.58 cm
Data indicates front feet of horses presented to Rochester Equine Clinic for shoeing 2000-2001. Values were measured using the Metron computerized measuring system by Eponatech. (Reilly, unpublished data).7,8
growth, and this in turn necessitates the use of shoes.1 Strasser admits that a seemingly sound horse may appear lame after removal of its shoes.1 She explains this phenomenon as the resensitizing of the foot after it has experienced lack of circulation from shoeing.1 As professional farriers, how do we interpret this information? The idea of a prescriptive trim or 1 ideal hoof remains questionable. Most farriers and equine veterinarians agree that the equine hoof is not a static form and has individual conformational issues that need to be addressed. The method of trimming is, presumably, critical to maintaining soundness and health. The true angle of the distal phalanx remains debatable. Research of feral horses’ feet does not support the phenomenon of naturally low angles that Strasser recommends.1,2 Most hoof angles, domestic and wild, fall into a slightly higher range of 50 to 55 degrees for the front feet.3,4,5,6 Biomechanical research has shown there are negative effects of low pastern angles (Balch, 1998).4 The benefit or harm of trimming out the bars and sole cannot be confirmed or denied by current research. Many of the horses shod at Rochester Equine Clinic are measured by using the Metron hoof measuring system.7 In an exercise of applying Dr. Strasser’s ideal values (in respect to dorsal wall angle, hairline angle, and heel height) to a hoof exhibiting the average values from our database8 for the same features, we encountered some dilemmas. The average angle of a front hoof was 7.3 degrees higher than the value Strasser advocates. The average heel height was 0.5 cm lower than the ideal heel height Strasser recommends. In applying the Strasser trim to a hoof with typical values for the features described, it would be necessary to increase the height of the heel while lowering to hoof angle. The only way to accomplish this is to increase the toe length. In the case of the hoof with average characteristics, the toe length would have to be increased by more than an inch to fit the
Volume 23, Number 11
Measured picture of a hoof trimmed by Strasser at Tufts University conference in 2002. Strasser acknowledges that the hoof will not meet her requirements in 1 shoeing (Reilly).
Strasser characteristics. Although Dr. Strasser does not expect every hoof to immediately fit her prescribed values, it does show the typical hoof would need to be remodeled considerably to comply. In addition to the nuances of the trimming method described, there is the complicating factor that the Strasser method is designed to be implemented by the horse owner. Because hooves are to be trimmed lightly 2 to 3 times a week, visits from equine professionals are not practical. It is often suggested that horse owners not consult their veterinarians or farrier, because our experiences are tainted by traditional educations systems. At a more insidious level, it has been suggested that farriers have a vested interest as professionals in applying shoes and maintaining lameness for the protection of our livelihoods, which unfortunately positions the farrier, veterinarian, and owner in an oppositional framework that inhibits the responsible care of the horse. As resident farriers at veterinary hospitals, we are obliged to use all of the new information available to us in the treatment of hoof diseases and lameness. We have examined controversial shoeing techniques in the past and assessed which techniques showed clinical improvements and then looked at the research to understand why. The Strasser method is unique in that clinical improvement is not expected, in some cases, for a number of years.1 How then are we to assess the value of this technique without scientific research? Should we use this system when presented with an acute laminitis case with shoes on? How are we to explain to the owners of a horse with navicular syndrome that we are pulling the shoes and he should be sound in the next 3 years? How many
503
horses would experience unnecessary suffering and be deprived of more efficacious treatment of a specific lameness? Strasser herself maintains that this system is
504
not appropriate for horses that spend more than 1 hour a day in a box stall.1 Clinical studies have been done to describe the effects (positive and negative) of horseshoes on the hoof. 9,10 None directly point to a level of damage Strasser claims occurs as a result of shoeing horses. Research has concluded that shoes do increase the level of vibration4 and restrict flexion and spreading of the hoof wall Colles, 1989.10,12,15 These studies do not, however, reach the extreme conclusions Strasser does relative to the effects of horseshoes. Other studies pose compelling questions about the internal functions of the hoof as well as the sensory receptors of the foot and the role of soft tissue structures.13,10 Again, these studies do not support Strasser’s assertions of the damaging effects of horseshoes. Historically, there arose a need for horses to wear shoes. Whether this need arose because of the change in work or from the alteration of the horses’ natural lifestyle is immaterial because we cannot return the horse to a totally natural state. While we wait for science to provide us with more answers, we must strive to find the answers for each horse and consider the effects of new theories. It cannot be argued that poor shoeing and inappropriate trimming of the horse’s foot can lead to damage and lameness.14 However, the goal and role of the farrier is to enhance the horse’s hoof health and aid its ability to perform whatever work it is asked to do, which is often achieved by careful evaluation and assessment of each horse as an individual when trimming and judiciously applying horseshoeing techniques. An underlying question when considering the Strasser method is: How does the farrier incorporate this
Journal of Equine Veterinary Science
November 2003
information into daily practice? When is it an appropriate method to introduce? When presented with difficult lameness cases, such as are seen at our respective institutions, how do we, in good conscience, recommend a method that has not been clinically researched? Dr. Strasser has clearly studied a wide variety of horse history, anatomy, and clinical studies, yet her methods remain promoted primarily through anecdotal evidence and testimonials. It is obvious that the anatomy, physiology, and biomechanics of the horse’s distal limb in sound and lame horses are complex subjects with more questions remaining than answers gained. It is through careful and controlled study that information is gathered and new methods developed. Many of the ideas promoted by Dr. Strasser are refreshing and appealing in their holistic view of how to maintain the optimum health of the domestic horse. Strasser has challenged many of us to reexamine our assumptions (and motives) of how and what we do to the horse in our attempt to “help,” which is always a positive outcome of any controversy, and we have been glad to take the opportunity to critically evaluate the role of the farrier and the work we do. Many of us do not pick up a foot without a stream of questions running forth as we try our best to make the wisest choice each day for each horse we are given to trim or shoe. As conscientious professional farriers, it is also our duty to do no harm, and until we feel confident that new methods have been carefully and humanely tested, we cannot promote the unknown.
Volume 23, Number 11
REFERENCES 1. Strasser H, Kells S. The Hoofcare Specialist’s Handbook: Hoof Orthopedics and Holistic Lameness Rehabilitation. 2001. 2. Strasser H. A Lifetime of Soundness: The Keys to Optimal Horse Health, Lameness Rehabilitation and the High-Performance Barefoot Horse. 1998. 3. Turner T. The use of hoof measurements for the objective assessment of hoof balance. 34th Equine Practitioners Convention Proceedings 1988;299-306. 4. Balch O, Butler D, White K, Metcalf S. Hoof balance and lameness: improper toe length, hoof angle and mediolateral balance. Compendium on Continuing Education for the Practicing Veterinarian, 1995;17:1275-83. 5. Butler D, Principles of Horseshoeing II. LaPonte, CO: Doug Butler, Publisher, 1985. 6. Jackson J. The Natural Horse: Lessons from the Wild for Domestic Horse Care. Flagstaff, AZ: Northland Publishing, 1992. 7. Craig J. Eponatech Metron: software for hoof conformation. Available at: www.eponatech.com. 2000;1-8. 8. Reilley, P. Unpubllished data; 2002. 9. Hinterhofer C, Stanek C, Haider H. Finite element analysis (FEA) as a model to predict effects of farriery on the equine hoof. Equine Vet J Suppl 2001;33:58-662. 10. Colles CM. Technique for assessing hoof function in the horse. Equine Vet J 1989;21:17-22. 11. Dyrhe-Poulsen P, Smedegaard HH, Roed J, Korsgaard E. Equine hoof function investigated by pressure transducers inside the hoof and accelerometers mounted on the first phalanx. Equine Vet J 1994;26:362-6. 12. Turner T. Proper shoeing and shoeing principles for the management of navicular syndrome. 34th Equine Practitioners Convention Proceedings 1988;299-306. 13. Bowker RM, Brewer AM, Vex KB, Guida LA, Linder KE, Sonea IM, et al. Sensory receptors in the equine foot. Am J Vet Res 1993;54:1840-4. 14. Balch O, Butler D, White K, Metcalf S. Hoof balance and lameness: foot bruising and limb contact. Compendium on Continuing Education for the Practicing Veterinarian 1995;17:1503-9. 15. Turner T, Stork C. Hoof abnormalities and the relation to lameness. 34th Equine Practitioners Convention Proceedings 1988;293-297.
505
T
hroughout much of the United States, conversations of the management of horse’s hooves have revolved around a recent phenomenon and technique known as the Strasser method. Many farriers, veterinarians, and, perhaps most important and surprising, horse owners have developed forceful opinions describing this approach to caring for the equine hoof. Advertisements in horse publications such as the Northeast Equine Journal (Northeast Equine J 15;7:127) advocate that owners learn to care for their animal’s feet themselves, with the aid of a weekend course. Although this may sound like a fad that will be quick to pass, advocates of the Strasser method forcefully expound on the positive effects of this barefoot trimming system. As professionals looking to provide the best care to our clients, what are we to make of this new system? How, and in what instances, should we be incorporating Dr. Strasser’s ideas, or when are they contraindicated?
What Is the Strasser Method? Dr. Hiltrud Strasser, DVM, of Germany presents a holistic view of horse care that admonishes against keeping horses in box stalls for any period, feeding on controlled schedules with no variation in types of feed or vegetation, not allowing for free movement and herd life. Such management, according to Strasser, leads to lameness and can only be rectified by adopting a more natural lifestyle as defined in her book A Lifetime of Soundness. Arguably, her more controversial concepts are directed toward the trimming and shoeing of horses. Strasser’s prescriptive trim deviates significantly from conventional horseshoeing practices. She proposes that horseshoes are detrimental to the horse and should never be used.1
From the University of Pennsylvania School of Veterinary Medicine, New Bolton Centera Kennett Square, Pennsylvania; and Rochester Equine Clinicb, Rochester, New Hampshire Copyright © 2003, Elsevier Inc. All rights reserved 0737-0806/03/2311-0012 $30.00/0 doi:10.1053/j.jevs.2003.10.012
502
Strasser claims her method will eliminate all lameness problems and restore natural function to the afflicted horse.1 Further, she maintains that these problems can be reversed or totally avoided by keeping horses unshod and trimming according to her suggestions.1 This article will examine these aspects of the Strasser method and evaluate them according to the available literature and research.
The Strasser Trim The particular elements of the Strasser trim are well described in her book. The ideal Strasser hoof is broad, with the heels, bulbs, and frog in full contact with the ground, thus supporting the horse and promoting the proper function of the foot. She maintains that the solar surface of the distal phalanx is parallel to the ground surface and that feet should be trimmed to accomplish this positioning. She describes the hairline as having a 30-degree angle when viewed laterally, with a heel height of 3 cm. The hoof should be trimmed to about a 45-degree angle on the front feet and a 55-degree angle on the hind feet.1 The bars are to be trimmed to 1 cm height shorter than the hoof wall and the sole pared from the apex of the frog back to the heels, creating a more concave shape and pliable thinness intended to allow for hoof expansion.1 Dr. Strasser believes this to be the most natural positioning for the distal limb and one that creates optimum health for the horse.
No Shoes The Strasser method rejects the use of horseshoes, stating that they are an “anesthetizing crutch”.1 She maintains that lameness is the result of keeping horses shod and can be reversed or avoided by keeping horses barefoot and trimmed according to her specifications.1 The basic thought process behind Strasser’s opposition to shoes is as follows: shoes interfere with the natural function of the hoof, which leads to a reduction of the neurologic sensations of the hoof. The mechanical interference from the shoe leads to diminished circulation of the hoof.1 Loss of circulation leads to poor-quality hoof
Journal of Equine Veterinary Science
November 2003
Table 1
Strasser advocated values Rochester Equine Clinic*
Dorsal wall angle (front Feet)
Hair line angle
Heel height
45 degrees
30 degrees
3.0 cm
52.38 degrees
23.31 degrees
2.58 cm
Data indicates front feet of horses presented to Rochester Equine Clinic for shoeing 2000-2001. Values were measured using the Metron computerized measuring system by Eponatech. (Reilly, unpublished data).7,8
growth, and this in turn necessitates the use of shoes.1 Strasser admits that a seemingly sound horse may appear lame after removal of its shoes.1 She explains this phenomenon as the resensitizing of the foot after it has experienced lack of circulation from shoeing.1 As professional farriers, how do we interpret this information? The idea of a prescriptive trim or 1 ideal hoof remains questionable. Most farriers and equine veterinarians agree that the equine hoof is not a static form and has individual conformational issues that need to be addressed. The method of trimming is, presumably, critical to maintaining soundness and health. The true angle of the distal phalanx remains debatable. Research of feral horses’ feet does not support the phenomenon of naturally low angles that Strasser recommends.1,2 Most hoof angles, domestic and wild, fall into a slightly higher range of 50 to 55 degrees for the front feet.3,4,5,6 Biomechanical research has shown there are negative effects of low pastern angles (Balch, 1998).4 The benefit or harm of trimming out the bars and sole cannot be confirmed or denied by current research. Many of the horses shod at Rochester Equine Clinic are measured by using the Metron hoof measuring system.7 In an exercise of applying Dr. Strasser’s ideal values (in respect to dorsal wall angle, hairline angle, and heel height) to a hoof exhibiting the average values from our database8 for the same features, we encountered some dilemmas. The average angle of a front hoof was 7.3 degrees higher than the value Strasser advocates. The average heel height was 0.5 cm lower than the ideal heel height Strasser recommends. In applying the Strasser trim to a hoof with typical values for the features described, it would be necessary to increase the height of the heel while lowering to hoof angle. The only way to accomplish this is to increase the toe length. In the case of the hoof with average characteristics, the toe length would have to be increased by more than an inch to fit the
Volume 23, Number 11
Measured picture of a hoof trimmed by Strasser at Tufts University conference in 2002. Strasser acknowledges that the hoof will not meet her requirements in 1 shoeing (Reilly).
Strasser characteristics. Although Dr. Strasser does not expect every hoof to immediately fit her prescribed values, it does show the typical hoof would need to be remodeled considerably to comply. In addition to the nuances of the trimming method described, there is the complicating factor that the Strasser method is designed to be implemented by the horse owner. Because hooves are to be trimmed lightly 2 to 3 times a week, visits from equine professionals are not practical. It is often suggested that horse owners not consult their veterinarians or farrier, because our experiences are tainted by traditional educations systems. At a more insidious level, it has been suggested that farriers have a vested interest as professionals in applying shoes and maintaining lameness for the protection of our livelihoods, which unfortunately positions the farrier, veterinarian, and owner in an oppositional framework that inhibits the responsible care of the horse. As resident farriers at veterinary hospitals, we are obliged to use all of the new information available to us in the treatment of hoof diseases and lameness. We have examined controversial shoeing techniques in the past and assessed which techniques showed clinical improvements and then looked at the research to understand why. The Strasser method is unique in that clinical improvement is not expected, in some cases, for a number of years.1 How then are we to assess the value of this technique without scientific research? Should we use this system when presented with an acute laminitis case with shoes on? How are we to explain to the owners of a horse with navicular syndrome that we are pulling the shoes and he should be sound in the next 3 years? How many
503
horses would experience unnecessary suffering and be deprived of more efficacious treatment of a specific lameness? Strasser herself maintains that this system is
504
not appropriate for horses that spend more than 1 hour a day in a box stall.1 Clinical studies have been done to describe the effects (positive and negative) of horseshoes on the hoof. 9,10 None directly point to a level of damage Strasser claims occurs as a result of shoeing horses. Research has concluded that shoes do increase the level of vibration4 and restrict flexion and spreading of the hoof wall Colles, 1989.10,12,15 These studies do not, however, reach the extreme conclusions Strasser does relative to the effects of horseshoes. Other studies pose compelling questions about the internal functions of the hoof as well as the sensory receptors of the foot and the role of soft tissue structures.13,10 Again, these studies do not support Strasser’s assertions of the damaging effects of horseshoes. Historically, there arose a need for horses to wear shoes. Whether this need arose because of the change in work or from the alteration of the horses’ natural lifestyle is immaterial because we cannot return the horse to a totally natural state. While we wait for science to provide us with more answers, we must strive to find the answers for each horse and consider the effects of new theories. It cannot be argued that poor shoeing and inappropriate trimming of the horse’s foot can lead to damage and lameness.14 However, the goal and role of the farrier is to enhance the horse’s hoof health and aid its ability to perform whatever work it is asked to do, which is often achieved by careful evaluation and assessment of each horse as an individual when trimming and judiciously applying horseshoeing techniques. An underlying question when considering the Strasser method is: How does the farrier incorporate this
Journal of Equine Veterinary Science
November 2003
information into daily practice? When is it an appropriate method to introduce? When presented with difficult lameness cases, such as are seen at our respective institutions, how do we, in good conscience, recommend a method that has not been clinically researched? Dr. Strasser has clearly studied a wide variety of horse history, anatomy, and clinical studies, yet her methods remain promoted primarily through anecdotal evidence and testimonials. It is obvious that the anatomy, physiology, and biomechanics of the horse’s distal limb in sound and lame horses are complex subjects with more questions remaining than answers gained. It is through careful and controlled study that information is gathered and new methods developed. Many of the ideas promoted by Dr. Strasser are refreshing and appealing in their holistic view of how to maintain the optimum health of the domestic horse. Strasser has challenged many of us to reexamine our assumptions (and motives) of how and what we do to the horse in our attempt to “help,” which is always a positive outcome of any controversy, and we have been glad to take the opportunity to critically evaluate the role of the farrier and the work we do. Many of us do not pick up a foot without a stream of questions running forth as we try our best to make the wisest choice each day for each horse we are given to trim or shoe. As conscientious professional farriers, it is also our duty to do no harm, and until we feel confident that new methods have been carefully and humanely tested, we cannot promote the unknown.
Volume 23, Number 11
REFERENCES 1. Strasser H, Kells S. The Hoofcare Specialist’s Handbook: Hoof Orthopedics and Holistic Lameness Rehabilitation. 2001. 2. Strasser H. A Lifetime of Soundness: The Keys to Optimal Horse Health, Lameness Rehabilitation and the High-Performance Barefoot Horse. 1998. 3. Turner T. The use of hoof measurements for the objective assessment of hoof balance. 34th Equine Practitioners Convention Proceedings 1988;299-306. 4. Balch O, Butler D, White K, Metcalf S. Hoof balance and lameness: improper toe length, hoof angle and mediolateral balance. Compendium on Continuing Education for the Practicing Veterinarian, 1995;17:1275-83. 5. Butler D, Principles of Horseshoeing II. LaPonte, CO: Doug Butler, Publisher, 1985. 6. Jackson J. The Natural Horse: Lessons from the Wild for Domestic Horse Care. Flagstaff, AZ: Northland Publishing, 1992. 7. Craig J. Eponatech Metron: software for hoof conformation. Available at: www.eponatech.com. 2000;1-8. 8. Reilley, P. Unpubllished data; 2002. 9. Hinterhofer C, Stanek C, Haider H. Finite element analysis (FEA) as a model to predict effects of farriery on the equine hoof. Equine Vet J Suppl 2001;33:58-662. 10. Colles CM. Technique for assessing hoof function in the horse. Equine Vet J 1989;21:17-22. 11. Dyrhe-Poulsen P, Smedegaard HH, Roed J, Korsgaard E. Equine hoof function investigated by pressure transducers inside the hoof and accelerometers mounted on the first phalanx. Equine Vet J 1994;26:362-6. 12. Turner T. Proper shoeing and shoeing principles for the management of navicular syndrome. 34th Equine Practitioners Convention Proceedings 1988;299-306. 13. Bowker RM, Brewer AM, Vex KB, Guida LA, Linder KE, Sonea IM, et al. Sensory receptors in the equine foot. Am J Vet Res 1993;54:1840-4. 14. Balch O, Butler D, White K, Metcalf S. Hoof balance and lameness: foot bruising and limb contact. Compendium on Continuing Education for the Practicing Veterinarian 1995;17:1503-9. 15. Turner T, Stork C. Hoof abnormalities and the relation to lameness. 34th Equine Practitioners Convention Proceedings 1988;293-297.
505