The Veterinary clinics of North America. Equine practice.
Publisher:
W.B. Saunders,
Frequency: Three no. a year
Country: United States
Language: English
Start Year:1985 -
ISSN:
0749-0739 (Print)
1558-4224 (Electronic)
0749-0739 (Linking)
1558-4224 (Electronic)
0749-0739 (Linking)
Impact Factor
1.1
2022
| NLM ID: | 8511904 |
| (DNLM): | SR0053812(s) |
| (OCoLC): | 11078671 |
| LCCN: | sn 84006968 |
| Classification: | W1 VE929F |
Cardiovascular Causes of Poor Performance and Exercise Intolerance and Assessment of Safety in the Equine Athlete. Horses have a high prevalence of resting arrhythmias, cardiac murmurs, and valvular regurgitation, and training can increase the prevalence. This makes it challenging for equine veterinarians who are asked to evaluate horses for poor performance to determine the clinical relevance of some findings. In addition, cardiac disease has the potential to cause collapse or sudden death, putting both the horse and rider at risk. Further diagnostics, such as echocardiograms and resting and exercising ECGs can help to sort out the impact of an abnormality found on resting physical examination. However un...
Cardiac Arrhythmias in Horses. Arrhythmias are common in horses. Sinus arrhythmia and first- and second-degree atrioventricular block are frequently found physiologic arrhythmias, but should immediately disappear after stress or exercise. Atrial premature depolarizations are usually not associated with poor performance, but are a potential trigger for atrial fibrillation. Atrial fibrillation results in an abnormal ventricular response during exercise and poses a risk for collapse in some horses. This arrhythmia can usually be treated by quinidine sulfate or transvenous electrical cardioversion. Ventricular premature depolar...
Assessment of the Cardiovascular System in Horses During Prepurchase and Insurance Examinations. Arrhythmias detected on prepurchase examination should be confirmed with an ECG. Exercising ECG determines if the arrhythmia is overdriven during exercise or is a safety concern. An echocardiogram is needed in all horses with a grade 3/6 or louder mid to late systolic, holosystolic, or pansystolic murmur or any holodiastolic decrescendo murmur to identify the cardiac abnormality and its hemodynamic impact. Most horses with arrhythmias and murmurs have a normal performance career and life expectancy and are insurable. Risks for sudden death and congestive heart failure associated with the commo...
Overview of Equine Cardiac Disease. Equine heart diseases can be categorized with morphologic, etiologic, and physiologic diagnoses and classified anatomically as diseases of the pericardium, myocardium, valves (endocardium), and great vessels. An appreciation of normal and pathologic physiology is a key to understanding diagnosis and therapy of heart disease. Pathophysiologic diagnoses include arrhythmias, congestive heart failure, and pulmonary hypertension. Heart rhythm disturbances can occur in isolation or with structural disease. Heart failure stems from arterial filling owing to insufficient cardiac output. Pulmonary hype...
Pericardial Disease, Myocardial Disease, and Great Vessel Abnormalities in Horses. Pericardial, myocardial, and great vessel diseases are relatively rare in horses. The clinical signs are often nonspecific and vague, or related to the underlying cause. Physical examination usually reveals tachycardia, fever, venous distension or jugular pulsation, a weak or bounding arterial pulse, ventral edema, and abnormal cardiac auscultation such as arrhythmia, murmur, or muffled heart sounds. The prognosis depends on the underlying cause and the disease progression, and ranges from full recovery to poor prognosis for survival. This article focuses on the etiology, diagnosis, prognosis,...
Cardiovascular Response to Exercise and Training, Exercise Testing in Horses. The physiology of exercise and training is fascinating, and hundreds of interesting studies have given insight into its mechanisms. Exercise testing is a useful clinical tool that can help veterinarians assess poor performance, fitness, and performance potential and prevent injuries. The clinically applicable aspects of cardiovascular adaptions to training and exercise testing are highlighted in this review. Different exercise tests should be used to evaluate horses performing in different disciplines and levels. Exercise tests that simultaneously assess several body systems can be beneficial ...
Equine Acquired Valvular Disease. Degenerative myxomatous disease is common and is associated with aging. Poor prognostic indicators for equine aortic regurgitation specifically include ventricular ectopy, increased pulse pressure, and hyperkinetic pulses. Valvular prolapse is a functional abnormality diagnosed echocardiographically, about which knowledge is limited. A better understanding of its role in valvular regurgitation is needed. Infective endocarditis presents with fever and other systemic signs accompanying valvular regurgitation. The prognosis is poor, warranting aggressive therapy. Other forms of valvular disease o...
Cardiac Monitoring in Horses. Monitoring variables of cardiac performance in horses is challenging owing to patient size, temperament, and anatomic peculiarities. Blood pressure is a major determinant of afterload, but it is not a reliable surrogate of cardiac performance and tissue perfusion. Cardiac output, together with arterial and venous oxygen content, provides insight as to the adequacy of delivery of blood and oxygen to the body as a whole and can be used to gauge the fluid responsiveness and cardiovascular status of the patient. Measurement of intracardiac pressures serves to assess cardiac filling pressures, myoc...
Equine Echocardiography. This article provides an overview on the principles of transthoracic echocardiography in horses. Indications for echocardiography, equipment, and technical considerations are discussed and a systematic approach for a complete echocardiographic examination in horses is described. Methods for assessment of chamber dimensions, allometric scaling of measurements, assessment of systolic and diastolic ventricular function, assessment of atrial function, hemodynamic assessment, and evaluation of valvular regurgitation are explained, focusing on traditional 2-dimensional (2D), motion-mode, and Doppler...
Equine Congenital Heart Disease. Congenital heart disease (CHD) represents a small proportion of horses undergoing clinical evaluation; however, both simple and complex defects occur during cardiac development leading to many unique malformations. This article reviews cardiac development and the fetal circulation, describes the morphologic method and the sequential segmental approach to CHD analysis, presents a summary of CHD in horses, and offers an overview of lesions that should be considered during evaluation of horses suspected to have CHD. For many forms of equine CHD, therapies are limited because cardiac interventions...
Equine Practice on Wound Management: Wound Cleansing and Hygiene. The goal of wound cleansing and care is the control or removal of tissue infection to allow healing in the most functional, cosmetic, fastest, and least expensive manner possible. This is accomplished through the removal of debris and necrotic tissue while reducing the bacterial load via careful use of mechanical techniques and cleaning agents, accepting that some level of tissue trauma will result. Keep in mind that the benefit of a clean wound must be weighed against the trauma inflicted in the process of cleansing. Veterinary health care professionals should take steps to reduce hospital-ac...
Topical Wound Medications. Topical therapies are used in equine wound healing to clean and decontaminate the wound environment after acute injury and to promote healing and decrease the risk of infection once the wound has initially been treated. Evolving antibiotic resistance has prompted judicious use of systemic antimicrobials, particularly in the treatment of local infections, such as wounds. The use of topical antiseptics to disinfect acute wounds and topical antimicrobials to manage chronic wounds is necessary to achieve successful healing. In addition, many topical medications can alter the wound environment to p...
Regenerative Medicine Therapies for Equine Wound Management. Wound management in horses can strike fear in some and passion in others. Wounds are common injuries in horses of all descriptions and requires exceptional knowledge and care to achieve a successful outcome. New treatments to overcome the critical challenges with equine wounds are always desired: managing dehisced and/or nonhealing wounds, managing exuberant granulation tissue, and ultimately achieving a functional tissue coverage. Regenerative medicine represents a broad set of tools with great promise to manipulate the deficiencies recognized in equine wound healing and improve the outcome.
Diagnostic Approaches to Understanding Equine Limb Wounds. An accurate and timely diagnosis of the systemic and local tissue influences of a wound are essential to target successful treatment measures and reach the best result for an affected horse. A complete physical examination should be completed for any wounded horse and appropriate systemic therapies instituted. Visual and manipulative examinations aid in the complete understanding of wounded tissues. Imaging and invasive diagnostic techniques also have value in determining the extent of a wound. Considering what tissues are involved from an inside-out perspective can assist in developing a comp...
Nonhealing Wounds of the Equine Limb. Nonhealing wounds present a common challenge to the equine practitioner. An underlying source of inflammation and infection is almost always present and needs to be resolved for healing to proceed. Wound débridement is the mainstay for this resolution. In addition, wound closure, wound dressings, and skin grafts can be used to achieve successful wound healing.
Equine Wounds over Synovial Structures. Equine septic synovitis commonly occurs secondary to traumatic wounds. The distal limbs of horses have minimal soft tissue protection, thus wounds in these areas are more likely to involve adjacent synovial structures. Synovial sepsis can be debilitating due to difficulties clearing established infections and the degenerative changes that result from ongoing inflammation. Prompt diagnosis allows for immediate treatment, improving the prognosis. Goals for successful treatment of infected synovial structures due to wounds include early and accurate recognition of the condition, rapid resolution ...
Wound Management: Wounds with Special Challenges. Distal limb wounds in horses heal substantially different than trunk wounds, commonly resulting in exuberant granulation tissue and exposed and sequestered bone. Surgical intervention of severe rectovaginal lacerations in the mare should be delayed until the tissues have heeled and scar tissue has remodeled. Wounds resulting in severe hemorrhage require appropriate emergent fluid therapy and potentially transfusion therapy.
Equine Wound Management: Bandages, Casts, and External Support. Successful management of equine wounds relies on knowledge of the stages of wound healing, factors that can alter those stages, how healing stages can be manipulated, and adherence to the principles of wound healing. Challenges that complicate wound management include the inability to immobilize and/or confine equine patients, and maintain a clean environment during the critical initial stages of healing. Because of these challenges, the equine practitioner relies heavily on bandaging and external coaptation techniques to successfully treat and manage wounds. The type of bandage used is dictat...
Choosing the Best Approach to Wound Management and Closure. This article aims to help the practitioner by providing the tools to decide which type of closure or healing is best in a given situation. An overview of the main criteria and the different approaches to wound closure is presented. Each wound must be considered as a unique problem that requires a clinician to take into account all of its characteristics and limits to determine the best management approach.
Medical Therapy in Equine Wound Management. Suitable use of prophylactic antimicrobial drugs for wounds depends on the accurate selection of appropriate antibiotics, dosing regimen, and duration of use. Regional intravenous delivery and intraosseous infusion of antibiotics are pivotal to a successful outcome for deep-rooted infections, inadequately perfused tissue, and infected wounds containing biofilm. Antibiotic-impregnated polymethylmethacrylate beads are predominantly helpful for wounds that have a poor blood supply and for those containing surgical implants that must remain in place.
Cardiac/Cardiovascular Conditions Affecting Sport Horses. Cardiac murmurs are not uncommonly detected in the equine athlete. Although most are benign in nature, differentiation and quantification of murmurs due to valvular regurgitation are important for prognosis and recommendations. Arrhythmias can be associated with structural disease or occur independently and may range in severity from minimal clinical effect to poor performance to presenting a safety risk to rider and horse. This article discusses commonly encountered cardiac conditions in the sport horse. Physical examination, diagnostic approach, valvular disease, and arrhythmias with an impa...
Borreliosis in Sport Horse Practice. Given the variable clinical signs attributed to Borrelia burgdorferi, including infectious arthritis, neurologic disease, and behavioral changes, B burgdorferi is an important differential for decreased performance in sport horses. The primary vectors (Ixodes tick species) are expanding their range and thus Borrelia species are located in a wider area, making exposure more likely. Due to regionally high seroprevalence and vague clinical signs, diagnosis of Lyme disease in the horse is believed overestimated. Antibiotics are first-line treatment of confirmed Lyme disease. A single positive sero...
Neurologic Conditions Affecting the Equine Athlete. EPM, CVSM, and EDM are currently recognized as the 3 most common neurologic diseases in US horses, with the latter 2 conditions being most prevalent in young animals. Moreover, horses competing at shows and performance events are at greater risk for exposure to highly contagious, neurologic EHV-1 outbreaks. A clinical diagnosis of any neurologic disease should be based on a careful history, complete neurologic examination, and appropriate diagnostic testing and interpretation. However, mild or early neurologic signs can often mimic or be mistaken for an orthopedic condition when horses present...
Lameness Evaluation of the Athletic Horse. Lameness examination is commonly performed in the athletic horse. A skilled lameness diagnostician must have keen clinical and observational skills. Evaluation starts with a detailed history and thorough physical examination. Next, gait evaluation in the moving horse is performed. Lame horses have asymmetrical body movement due to unconscious shift of body weight. Recognition of the resultant head nod and pelvic hike is the basis for lameness diagnosis. Lameness identification is enhanced by circling, limb flexions, and riding. Most lame horses do not exhibit pathognomonic gait characteristics...
Diagnosis of Skeletal Injury in the Sport Horse. This article discusses the basis of image formation of radiography, scintigraphy, PET, computed tomography (fan beam and cone beam), and magnetic resonance as it relates to imaging of musculoskeletal injury in the sport horse. The benefits and drawbacks of each modality are discussed with particular emphasis on sensitivity, specificity, and accuracy of identification of subchondral bone injury. Examples of straightforward as well as confounding lesions are provided, emphasizing the need for appropriate clinical workup and diagnostic analgesia, where appropriate.
Lower Airway Disease in the Athletic Horse. The airways are the first part of the pathway in the oxygen transport chain that is critical to excellent athletic performance, and the lower airways are considered the final gatekeeper before oxygen enters the blood and carbon dioxide exits. Horses are blessed with large airways and lungs that allow them to be superb athletes, but the down side of this largesse on the part of evolution is that unless they are truly elite athletes they may withstand noninfectious disease of the lower respiratory tract for months to years before the owner or trainer notices. The two conditions of the lower resp...
Understanding the Basic Principles of Podiatry. Foot-related lameness is one of the most frequently encountered problems in the equine industry. Therapeutic shoeing is a frequently used preventative discipline for the treatment of many causes of lameness. The primary goal for therapeutic applications is to offset the mechanical limitations and enhance the healing environment. Equine podiatry is a blend of the 2 highly respected professions each contributing to the task at hand, but neither formally educated and trained as collaborative team members with a common thread of podiatry principles.
Endocrine Disorders of the Equine Athlete. Equine athletes are affected by 2 major endocrine/metabolic disorders, insulin dysregulation (ID) and pituitary pars intermedia dysfunction. ID is a risk factor for laminitis in horses, which poses the greatest threat to performance because of the damage that it causes to hoof structures. This article includes an in-depth discussion of ID and other risk factors for laminitis that are grouped together as equine metabolic syndrome. As horses age, the risk of pituitary pars intermedia dysfunction increases, and this endocrine disorder may exacerbate preexisting ID and further increase the risk of...
Equine Manual Therapies in Sport Horse Practice. Manual therapies involve the application of the hands to the body, with a diagnostic or therapeutic intent. Touch therapies, massage, joint mobilization, and manipulation are all critical components in the management of muscular, articular, and neurologic components of select injuries in performance horses. Musculoskeletal conditions that are chronic or recurring, not readily diagnosed, or are not responding to conventional veterinary care may be indicators that manual therapy evaluation and treatment is needed.