Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
PREPUBLICATION COPY A Review of Methods for Detecting Soreness in Horses Committee on a Review of Methods for Detecting Soreness in Horses Board on Agriculture and Natural Resources Division on Earth and Life Studies A Consensus Study Report of
THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001 This activity was supported by contracts between the National Academy of Sciences and Tennessee Department of Agriculture, Tennessee Walking Horse Breeders Foundation, U.S. Department of Agriculture - Animal and Plant Health Inspection Service under contract numbers 10003803 and 10005226. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project. Digital Object Identifier: https://doi.org/10.17226/25949 Additional copies of this publication are available from the National Academies Press, 500 Fifth Street, NW, Keck 360, Washington, DC 20001; (800) 624-6242 or (202) 334-3313; http://www.nap.edu. Copyright 2021 by the National Academy of Sciences. All rights reserved. Printed in the United States of America Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2021. A Review of Methods for Detecting Soreness in Horses. Washington, DC: The National Academies Press. https://doi.org/10.17226/25949.
The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. John L. Anderson is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.nationalacademies.org.
Consensus Study Reports published by the National Academies of Sciences, Engineering, and Medicine document the evidence-based consensus on the studyâs statement of task by an authoring committee of experts. Reports typically include findings, conclusions, and recommendations based on information gathered by the committee and the committeeâs deliberations. Each report has been subjected to a rigorous and independent peer-review process and it represents the position of the National Academies on the statement of task. Proceedings published by the National Academies of Sciences, Engineering, and Medicine chronicle the presentations and discussions at a workshop, symposium, or other event convened by the National Academies. The statements and opinions contained in proceedings are those of the participants and are not endorsed by other participants, the planning committee, or the National Academies. For information about other products and activities of the National Academies, please visit www.nationalacademies.org/about/whatwedo.
COMMITTEE ON A REVIEW OF METHODS FOR DETECTING SORENESS IN HORSES Members JERRY BLACK (Chair), Colorado State University ROBIN FOSTER, Private Consultant; University of Puget Sound; University of Washington PAMELA EVE GINN, University of Florida, Gainesville SARAH LE JEUNE, University of California, Davis BART SUTHERLAND, Private Practitioner, Oxford, Mississippi TRACY ACE TURNER, Turner Equine Sports Medicine and Surgery, Stillwater, Minnesota SUSAN L. WHITE, University of Georgia, Athens (Emerita) Staff CAMILLA YANDOC ABLES, Study Director JENNA BRISCOE, Research Associate SARAH KWON, Senior Program Assistant Report Editor ROBERT POOL Prepublication Copy v
BOARD ON AGRICULTURE AND NATURAL RESOURCES Members CHARLES W. RICE (Chair), Kansas State University, Manhattan ARISTOS ARISTIDOU (NAE), Cargill, Inc., Minneapolis, MN SHANE C. BURGESS, University of Arizona, Tucson SUSAN CAPALBO, Oregon State University, Corvallis GAIL CZARNECKI-MAULDEN, NestlÃ© Purina PetCare, St. Louis, MO BERNADETTE DUNHAM, Milken Institute of Public Health, George Washington University, Washington, DC GEBISA EJETA, Purdue University, West Lafayette, IN JAMES S. FAMIGLIETTI, University of Saskatchewan, Saskatoon, Canada FRED GOULD (NAS), North Carolina State University, Raleigh JOHN HAMER, DCVC Bio, San Francisco, CA DOUGLAS B. JACKSON-SMITH, Ohio State University, Wooster JAMES W. JONES (NAE), University of Florida, Gainesville ERMIAS KEBREAB, University of California, Davis STEPHEN S. KELLEY, North Carolina State University, Raleigh JAN E. LEACH, Colorado State University, Fort Collins ROBIN LOUGEE, IBM Research, Yorktown Heights, NY JILL J. MC CLUSKEY, Washington State University, Richland KAREN I. PLAUT, Purdue University, West Lafayette, IN RICARDO SALVADOR, Union of Concerned Scientists, Washington, DC V. ALARIC SAMPLE, George Mason University, Fairfax, VA Staff ROBIN A. SCHOEN, Director CAMILLA YANDOC ABLES, Senior Program Officer KARA N. LANEY, Senior Program Officer JENNA BRISCOE, Research Associate SARAH KWON, Senior Program Assistant vi Prepublication Copy
Acknowledgment of Reviewers This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We thank the following individuals for their review of this report: Kent Allen, Virginia Equine Imaging Jeffrey Baker, Department of Veterans Affairs Keith Dane, Humane Society of the United States David Gardiner, Animal Reference Pathology Camie Heleski, University of Kentucky Tom Lenz, Equus Curito Equine Center Susannah Lewis, Rainland Farm Equine Clinic Smith Lilly, Mercer Springs Farm Mark Matson, International Walking Horse Association Sue McDonnell, University of Pennsylvania Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report, nor did they see the final draft before its release. The review of this report was overseen by Dr. Brian D. Nielsen, Michigan State University, and Dr. Barbara Schaal (NAS), Washington University in St. Louis. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies. Prepublication Copy vii
Preface The Tennessee walking horse (TWH) is an integral part of the American culture of the South, where its origins can be traced to the 18th century. The breed evolved out of necessities for horses used for transportation and utility on the farms and plantations of the southern United States and was known for its stamina, smooth gait, and even disposition. During the last century and today the horse has been used primarily for pleasure and show competition. As the popularity of the TWH grew, so did the desire among owners and trainers to showcase its beauty, quality, and athletic abilities at horse show competitions. Unique and natural to the breed is a smooth four-beat ârunning walkâ gait. In the 1950s the accentuated or exaggerated running walk, known as the âbig lickâ became popular at high-level competitions. The combination of exaggerated high-action step in front and long stride behind is still considered desirable in todayâs horse show competitions, and it is often achieved through soring. Soring is the practice of applying a substance or mechanical device to the lower limb of a horse that will create enough pain that the horse will exaggerate its gait to relieve the discomfort. Soring became popular at TWH shows in the mid-20th century, and by 1970 it became enough of a public concern for the welfare of the horse that Congress put into law the Horse Protection Act (HPA). The HPA specifically addresses the practice of soring by prohibiting the showing, exhibition, or sale of TWHs that are found to be sore. Progress has been made, but sadly soring is still being done even after 50 years of HPA enforcement. By all accounts from both the public and equine health and welfare professionals, soring is considered an inhumane practice and must be eliminated. To the credit of the Tennessee walking horse industry and the U.S. Department of Agriculture (USDA), funding was provided for a National Academies of Sciences, Engineering, and Medicine (the National Academies) committee to conduct a review of the methods for detecting soreness in horses, in hopes of advancing the goal of ultimately eliminating the act of soring in horses and improving the welfare of TWHs. I want to thank the experienced scientists and clinicians in a variety of equine disciplines who served on the committee for their remarkable dedication to the work involved in preparing this report. Those efforts include hours of literature reviews, multiple committee meetings, working with and learning from numerous presenters who have expertise in various aspects of health and welfare of the horse, and writing working drafts with many edits to make the report readable and of high quality. I also want to thank our wonderful team from the National Academies who worked diligently for many months to keep us on track and gave their total support throughout the entire process. On the committeeâs behalf, I especially want to thank our study director, Camilla Yandoc Ables, for her assistance through virtually every aspect of the development of this report. Her leadership, knowledge, and determination to assist the committee in every way possible to produce a report that will significantly contribute to the scientific literature for the welfare of these great horses cannot be understated. The committee would also like to thank the rest of the National Academies team, Robin Schoen, Jenna Briscoe, and Sarah Kwon, for their invaluable assistance to the committee. Special thanks to Rachel Reed, representative of the SHOW HIO, for the horse inspection videos; Paul Stromberg and Lynne Cassone for the slides that helped greatly with the review of the scar rule; and the representatives of the study sponsors, Tom Blankenship and Aaron Rhyner, for all the information and assistance they provided to the committee. Last, I want to thank the numerous scientists, equine professionals, individuals previously with the Animal Care Horse Protection Program at USDAâs Animal and Plant Health Inspection Service, and members of the public who contributed to the committeeâs knowledge and understanding of issues important to the study and ultimately to the industry. Jerry B. Black, Chair Committee on a Review of Methods for Detecting Soreness in Horses Prepublication Copy ix
Contents SUMMARY ..............................................................................................................................1 1 INTRODUCTION............................................................................................................ 11 The Tennessee Walking Horse, 11 The Horse Protection Act of 1970, 12 Purpose of the Study and Committeeâs Charge, 15 Committeeâs Approach to Its Charge, 16 Organization of the Report, 18 References, 18 2 METHODS USED TO IDENTIFY SORENESS IN WALKING HORSES ........................... 20 The Inspection Process, 20 Horse Inspectorsâ Qualifications and Training, 25 Methods Currently Used to Inspect Horses for Soreness, 27 Methods for Detecting Soreness Not Currently Used in Horse Inspections for HPA Enforcement, 34 Recommendations, 41 References, 42 3 NEW AND EMERGING METHODS, APPROACHES, AND TECHNOLOGIES FOR DETECTI NG PAIN AND ITS CAUSES ............................................................................ 45 Introduction, 45 Variability of Pain Expression, 50 Behavioral Assessment of Pain, 51 Behavioral Indicators of Pain, 53 Physiological Assessment of Pain, 63 Clinical Assessment of Pain, 65 Recommendations, 67 References, 68 4 REVIEW OF THE SCAR RULE FOR DETERMINING COMPLIANCE WITH THE HORSE PROTECTION ACT ........................................................................................... 73 The Horse Protection Act and Application of the Scar Rule, 73 Clinical Dermatologic Examination, Microscopic Anatomy of the Skin, and Pertinent Definitions, 74 Microscopic Evaluation of Skin Biopsies of Tennessee Walking Horses Found to Be in Violation of the Scar Rule, 77 Evaluation of the Scar Rule Criteria for Compliance with the Horse Protection Act, 81 Recommendation, 84 References, 85 APPENDIXES A BIOGRAPHICAL SKETCHES OF COMMI TTEE MEMBERS ......................................... 86 B OPEN SESSION AND WEBI NAR AGENDAS................................................................... 89 Prepublication Copy xi
Contents C THE HORSE PROTECTION ACT OF 1970 â REGULATIONS ....................................... 92 LIST OF BOXES, FIGURES, AND TABLES BOXES S-1 Statement of Task, 3 1-1 Horse Protection Efforts in the United States (1970 to 2019), 13 1-2 9 C.F.R. Â§ 11.3 Scar Rule, 15 1-3 Statement of Task, 16 2-1 International Federation for Equestrian Sports Limb Sensitivity Testing Procedure, 29 2-2 Committeeâs Observations Based on Videos of Inspections Performed by Designated Qualified Persons, 29 4-1 Ultrasonography to Study Pastern Tissue Injury in Tennessee Walking Horses, 84 FIGURES 2-1a Horse inspection process when a designated qualified person (DQP) is present at a horse show (no veterinary medical officer), 22 2-1b Horse inspection process when a designated qualified person (DQP) and a veterinary medical officer (VMO) are present at a horse show, 23 2-2 Horse inspection process when there is one VMO at a horse show, 24 2-3 Horse inspection process when there are two veterinary medical officers (VMOs) at a horse show, 25 2-4 Thermographic images of horse palmar pastern, 35 2-5 Thermographic images of fore pasterns of two different horses, 35 2-6 Radiographs showing hoof wall width and sole depth, 38 2-7 Radiographs of illegal substances inside hoof packages, 38 2-8 Radiograph showing a rotation of >5 degrees, 39 2-9 Radiographs of a lateral view of an illegal metal pad and a legal weight on the sole of the package and a dorsal palmar view of an illegal metal pad and a legal weight on the sole of the package, 39 3-1 Horse Grimace Scale, 57 3-2 âPain faceâ diagram for clinical use, 59 3-3 Photographs captured from videotaped standing inspections by designated qualified persons before (left) and during (right) palpation, 60 4-1 Diagram of the skin illustrating the types of endogenous and exogenous factors that can affect the integrity of the skin, 74 4-2 Microscopic anatomy of the skin, 75 4-3 Examples of primary and secondary lesions of the skin, 76 4-4 Example of the evolution of a lesion over time, 78 4-5a Photomicrograph of the caudal pastern of the skin of a horse included in the Stromberg study, 78 4-5b Photomicrograph of the normal skin of the caudal pastern of a horse, 78 4-6 Lichenified skin on the mane of a horse, 78 4-7 Microscopic image of lichenification, 79 xii Prepublication Copy
Contents 4-8 Normal appearance of the skin of the palmar aspect of a horse, 81 4-9 Pastern of a chronically sored horse in violation of the scar rule, 81 TABLES 3-1 Score Sheet for the EQUUS-COMPASS Composite Pain Scale, 54 3-2 Obel Laminitis Grades for Rating a Horseâs Withdrawal from Pressure/Palpation of Localized Area, 55 3-3 Facial Features of Horses in Pain, 56 3-4 Score Sheet for the Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP) Scale, 59 3-5 Behavioral Assessment Scales Basis, Pros, and Cons, 61 Prepublication Copy xiii