Clinical Techniques in Equine Practice最新文献

A wide variety of infectious bacterial, viral, and protozoal reproductive pathogens have the potential to be transmitted by the breeding stallion. In addition, nonvenereal diseases can also be spread due to the close proximity of mares and stallions during natural service. Disease spread by assisted breeding techniques is also possible. The equine veterinarian must develop a thorough understanding of the relevant diseases and be able to formulate treatment and management plans to minimize the effects of infection on breeding programs.

Vascular disorders play an important role in male infertility. Various modalities of ultrasound examination can be applied to evaluate testicular vasculature and to objectively measure numerous parameters of testicular perfusion. This paper describes techniques of ultrasound examination of testicular vasculature in the stallion, using gray-scale, color, and power Doppler ultrasound. Results of studies on the normal vascular anatomy in the stallion and its variations, the methods of obtaining most optimal measures of testicular perfusion, and the effects of the physiological and pharmacological factors on testicular blood flow are reviewed. There is a growing body of evidence that evaluation of testicular vasculature has a tremendous clinical relevance and should be included in the diagnostic workup of scrotal diseases.

Testicular degeneration is a common cause of subfertility and infertility in stallions. The disease can broadly be divided into two categories: those cases resulting from a known testicular insult, and idiopathic (senile or age-related) testicular degeneration. This manuscript describes the problem of testicular degeneration in the equine breeding industry and summarizes what is known about the pathophysiology of the disease. Additionally, the clinical signs of testicular degeneration are reviewed so that the clinician can more quickly and accurately arrive at a diagnosis. Differences in the approach to treatment of testicular degeneration arising from a known cause and idiopathic testicular degeneration are discussed as are differences in prognoses. Finally, the practitioner is provided with practical information on how to more effectively manage affected stallions and what, if anything, can be done to improve reproductive performance of these animals both in the field and in a referral setting.

Evaluation of sperm morphology is an important part of stallion breeding soundness evaluation. The objectives of this review are to discuss the pathogenesis of sperm defects and describe some of the sperm abnormalities present in the ejaculate of stallions.

Assessment and management of an enlarged scrotum in the stallion presents a diagnostic and therapeutic challenge. Depending on the etiology and severity of the enlargement, irreversible injury may result to the reproductive system and adjacent structures. Although appearing clinically similar, scrotal enlargements vary widely in their cause. Interventions should be aimed at evaluation of the structures involved, with assessment of the degree of tissue compromise followed by timely and rational medical and surgical therapies.

Standing stallions for natural service is a commitment that should not be entered into without careful thought and planning. It can be a very exciting and financially rewarding endeavor, but without proper thought, it is apt to turn into a disaster. Proper facilities, adequate competent staff, and well-managed horses are a must if the operation is to be successful. The lack of planning and preparation has the potential to turn a worthwhile idea into a nightmare that will likely deliver poor results and could become a liability to the industry. Good stallion management and disease control are a must for even the smallest of operations. Proper planning and competent advice will be time and money well spent no matter what the size of the operation that is planned.

Horse owners worldwide now request that their mares be bred with cooled or frozen-thawed transported semen, owing to the advantages of avoiding mare transport (often with a foal by her side), decreasing disease transmission between farms, and most importantly, the accessibility to a wider genetic pool. This has become commonplace practice as many breed registries now allow the use of transported semen for producing foals worthy of registration. However, problems arise as optimal steps for both semen handling and preparation, as well as for mare breeding management, are not practiced. Therefore, the objective of this manuscript is to provide veterinary practitioners with an overview about optimal management techniques related to both handling semen and mare management for attaining successful results. Common problems and dilemmas encountered will be also discussed and emerging research introduced. Whereas appropriate protocols for handling and preparing semen for cooled-transport will be presented with some detail, it is beyond the scope of this paper to discuss stallion semen cryopreservation, which typically requires extensive equipment investment and expertise and is usually done at referral and specialized centers. This text assumes that the equine veterinary practitioner already has some basic skills in regards to stallion semen collection and evaluation, as well as in performing examination of the mare via transrectal palpation and ultrasonography for breeding management purposes.

The manner in which a stallion is initially introduced to breeding can have long-lasting effects on his breeding behavior, with implications for safety, and breeding efficiency of the horse. So successfully starting a novice stallion in an organized positive manner has become a typically satisfying challenge for our team. This how-to paper details what we at our veterinary school stallion referral clinic believe to be key handling concepts, facilities, equipment, personnel, training schedule and goals for getting novice breeders off to a good start. Also included is the specific breeding shed protocol that is used routinely at our stallion referral clinic for natural service or semen collection, as an example of one method that has worked well with all types of stallions in a teaching environment that involves new student handlers with a variety of levels of skill and experience.

Tendon and ligament injuries are common in athletic horses and can be difficult to treat successfully. Tendons and ligaments are characterized by sparse fibroblasts embedded in a complex structural hierarchy of collagen-rich extracellular matrix (ECM) organized along lines of tension. This precise organizational scheme imparts the necessary mechanical properties for tendons and ligaments to function under high loads. The etiology of tendon and ligament injuries remains the subject of numerous ongoing research projects; however, acute overloading and accumulated microtrauma are the two predominant theories. Under normal physiologic loading, a balance is maintained between the degeneration of ECM and its repair by the resident fibroblast population. When damage occurs faster than it can be repaired, clinical signs of tendonitis or desmitis develop. The molecular and cellular responses that occur during tendon and ligament healing are important to understand, as they provide key points of control that may be targeted for new therapies.

Magnetic resonance (MR) imaging is the gold-standard imaging modality for diagnosing tendon and ligament pathology. MR is capable of detecting lesions that are not visible with other imaging modalities. Pathologic changes in tendons and ligaments are seen on MR as changes in size, shape, and/or signal intensity of the affected structure. All tendons and ligaments have individual characteristics and variations in normal appearance. This chapter describes the normal MR appearance of the tendons and ligaments of the distal limb, as well as discussing the ways in which damage to individual tendons and ligaments affects how they appear on MR images.