Advances in Laminitis, Part I, An Issue of Veterinary Clinics: Equine Practice

Christopher C. Pollitt

Description

Articles include: The Anatomy and Physiology of the Lamellar, Dermal-Epidermal Interface, Carbohydrate Alimentary Overload Laminitis, Events in the Hindgut, Therapeutic Hypothermia (cryotherapy) to Prevent and Treat Acute Laminitis, Acute Laminits: Supportive Medical Therapy, First Aid for the Foot: Therapeutic and Mechanical Support, Serial Venography after Carbohydrate-Induced Laminitis, Venography and Its Clinical Application in North America, Chronic Laminitis: Strategic Hoof Wall Resection, The Laminar Wedge of Chronic Laminitis, Lysis of the Distal Phalanx in Chronic Laminitis, Chronic Laminitis Foot Support: Clogs, Homecare for the Chronic Laminitis Case, The Pharmacological Basis for the Treatment of Developmental and Acute Laminitis, and Black Walnut Extract Laminitis: An Inflammatory Model.

Sujets

• Equine
• Veterinary Medicine
• Medical
• Médecine

Informations

• Publié par: Saunders
• Date de parution: 10 mai 2010
• Nombre de lectures: 0
• EAN13: 9781455700752
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Veterinary Clinics of North America: Equine Practice , Vol. 26, No. 1, April 2010
ISSN: 0749-0739
doi: 10.1016/S0749-0739(10)00014-3

Contributors
Veterinary Clinics of North America: Equine Practice
Advances in Laminitis, Part I
Christopher C. Pollitt
School of Veterinary Science, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
ISSN  0749-0739
Volume 26 • Number 1 • April 2010

Contents
Cover
Contributors
Forthcoming Issues
Preface
A Historical Perspective of Laminitis
80 Causes, Predispositions, and Pathways of Laminitis
Laminitis Treatment: A Personal Memoir
The Anatomy and Physiology of the Suspensory Apparatus of the Distal Phalanx
Overview of Current Laminitis Research
Carbohydrate Alimentary Overload Laminitis
Microbial Events in the Hindgut During Carbohydrate-induced Equine Laminitis
Black Walnut Extract: An Inflammatory Model
Acute Laminitis: Medical and Supportive Therapy
The Pharmacologic Basis for the Treatment of Developmental and Acute Laminitis
Therapeutic Hypothermia (Cryotherapy) to Prevent and Treat Acute Laminitis
Progression of Venographic Changes After Experimentally Induced Laminitis
Clinical Presentation, Diagnosis, and Prognosis of Chronic Laminitis in North America
Pathology of the Distal Phalanx in Equine Laminitis: More Than Just Skin Deep
Equine Venography and Its Clinical Application in North America
The Lamellar Wedge
Chronic Laminitis: Strategic Hoof Wall Resection
The Use of the Wooden Shoe (Steward Clog) in Treating Laminitis
Home Care for Horses with Chronic Laminitis
Index
Veterinary Clinics of North America: Equine Practice , Vol. 26, No. 1, April 2010
ISSN: 0749-0739
doi: 10.1016/S0749-0739(10)00016-7

Forthcoming Issues
Veterinary Clinics of North America: Equine Practice , Vol. 26, No. 1, April 2010
ISSN: 0749-0739
doi: 10.1016/j.cveq.2010.02.001

Preface

Christopher C. Pollitt, BVSc, PhD
School of Veterinary Science, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
The Laminitis Institute, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, Kennett Square, PA, USA
E-mail address: [e-mail]

Christopher C. Pollitt, BVSc, PhD Guest Editor
Despite centuries of close contact with mankind, horses still develop laminitis. This may cripple them, shorten their working lives, and euthanasia may be recommended because of the dreadful suffering. The causes of laminitis remain a mystery despite a considerable international research effort. With increasing intensity, teams of research scientists and postgraduate students have, for the past 70 years, studied the causes, prevention, and therapy for laminitis. As usual with research into difficult biologic problems, every question answered seems to generate more unknowns. Poor funding for laminitis research prevents rapid progress, but nevertheless some aspects of laminitis have become a little clearer although others seem more complex and unreachable. The current importance of laminitis is reflected in the decision by the editors of Veterinary Clinics of North America: Equine Practice to dedicate not just 1, but 2 issues to the topic of laminitis. The first issue deals mainly with laminitis associated with septic/inflammatory conditions and the second concentrates on metabolic and endocrinopathic laminitis. Both issues include articles on treatment/preventive strategies and how to cope with chronic laminitis, the aftermath of the acute stage.
Ten years have passed since David Hood edited the landmark edition in this series entitled Laminitis . Readers are encouraged to consult the 1999 issue, as much of the material is current and needs little revision. In particular, the terminology for the stages of laminitis, outlined in Fig. 1, p. 289, 1 has been universally adopted and is used throughout the current editions. Thus, there is an initial developmental phase when the inducing mechanisms begin to operate and lead to the onset of lameness. This is the phase when preventive strategies have the best chance of succeeding (see article by Andrew van Eps in this issue), but unfortunately, it is relatively asymptomatic and may not be recognized in clinical practice. All too frequently, a therapeutic opportunity is lost. In the second acute phase of laminitis, the clinical signs are clear and have never been better described than by Nils Obel in 1948. 2 Obel’s 4 degrees of lameness range from mild to very severe. Part of the description of the first mild stage includes paddling or shifting weight from 1 foot to the other every few seconds while in the standing position. Although strictly speaking not a gait abnormality or true lameness, shifting weight while standing still is an important observation as even this early subtle clinical sign is associated with histologic and ultrastructural lesions (see article by Pollitt and Visser in this issue).
As in the 1999 edition, Henry Heymering has provided a historical perspective on laminitis which is always salutary to read. Confronted by the same phenomenon of developing and then acute laminitis, the veterinary scientific minds of the distant and recent past have repeatedly developed opposing etiologic and pathophysiologic opinions. Understanding laminitis has yet to fall to the scientific method. Read Heymering’ article from the beginning and you will be rewarded by this pearl at the end: “We have had nearly 2000 years of bleeding as treatment, 1700 years of exercise as treatment, and more than 40 years of phenylbutazone as treatment – without proof of effectiveness in treating laminitis. Although longevity suggests effectiveness, until we have proof of our treatments, future generations may find them as quaint and misdirected as we find ‘the skin of the weasel cut up in small pieces, together with butter, putrid egg, and vinegar’ as the treatment recommended by Heresbach (1577).” Senior veterinary practitioners have personal experience of the confusion in the laminitis literature and a memoir by Donald Walsh relates the frustration of living through times of high expectation and bitter disappointment with what was delivered by laminitis researchers. It behooves laminitis researchers to listen to equine clinicians as they are still waiting for effective preventive and therapeutic strategies. Clinicians play an important role in laminitis research and retrospective analyses of their clinical records are urgently needed to shed light on what is truly making a difference in terms of prevention and treatment.
Responding to Nils Obel’s 1948 statement that “a profound knowledge of the anatomical changes in the initial stages must be considered a prerequisite for the study of the patho-physiology of the disease,” a revision entitled “The anatomy and physiology of the suspensory apparatus of the distal phalanx” is provided. The laminitis literature receives a comprehensive review and this is followed by articles with the latest information on the effect of laminitis induced by carbohydrate overload and black walnut extract. Current therapy is covered by 2 articles and a third reviews the preventive potential of distal limb hypothermia (cryotherapy). There are 2 articles on venography, 1 research based and the other clinical; these are to bring the reader up-to-date with the progress being made with this informative diagnostic technique. Chronic laminitis and its sequelae are reviewed from a clinician’s viewpoint and then by a pathologist. Specific bone pathology of the distal phalanx following severe chronic laminitis has received little attention in the past and this article delivers important new information that segues appropriately into discussions on the destructive potential of the lamellar wedge and the indication for strategic hoof wall resection. For the first time in the veterinary literature, software that takes the information generated by the computed tomography scanner and renders it into a virtual three-dimensional model using MIMICS (Materialise, Belgium), is used to illustrate the lamellar wedge and its association with the pathologic lysis of the distal phalanx in severe chronic laminitis.
The final articles offer advice on supporting the chronically affected foot and how best to care for afflicted horses in their home environment. Of necessity, the topics of some articles reappear in Part II of this series as other experts are recruited to advance laminitis understanding.

Acknowledgments
I am grateful to Dr Simon Turner and John Vassallo for the opportunity to serve as guest editor and author of the Veterinary Clinics of North America: Equine Practice . The contributing authors are thanked for devoting the time to share their knowledge and experience with an audience that will learn much about laminitis within the pages of Parts I and II of Advances in Laminitis .

References

   1. D.M. Hood. Laminitis in the horse. Vet Clin North Am Equine Pract . 1999;15:287-294.
   2. N. Obel. Studies of the histopathology of acute laminitis: Almgvist and Wilcsells Bottrykeri Ab Uppsala. (PhD thesis). Royal Veterinary College: Stockholm, Sweden; 1948.
Veterinary Clinics of North America: Equine Practice , Vol. 26, No. 1, April 2010
ISSN: 0749-0739
doi: 10.1016/j.cveq.2009.12.004

A Historical Perspective of Laminitis

Henry W. Heymering, CJF, RMF
8621A Hunters Drive, Frederick, MD 21701, USA
E-mail address: horseu@earthli