John R. Pascoe

Penetrating wounds of the thorax in 15 horses

Clinical features, treatment and outcome of 15 horses with penetrating thoracic wounds are described. The most common cause of trauma was collision with an object (10 horses). Concurrent clinical findings included subcutaneous emphysema (12 horses), pneumothorax (12 horses), haemothorax (5 horses) and pneumomediastinum (6 horses). Axillary wounds were present in 5 horses. Foreign bodies were identified and removed from 2 horses. Wounds were sutured (6 horses) or packed (7 horses). Air was evacuated from the pleural cavities of 11 horses. Eleven horses (73%) were discharged from the hospital. All horses subjected to euthanasia had severe trauma to structures outside the thoracic cavity including perforation of the colon (2 horses), renal trauma (1 horse) and a luxated thoracolumbar vertebra (1 horse). From this study, it can be concluded that 1) the prognosis for horses with penetrating thoracic wounds, without extrathoracic injury, is favourable; 2) a thorough evaluation including the abdominal cavity should be performed and 3) horses with axillary wounds should be monitored closely for respiratory distress until the wound has completely healed.

Displacements, malpositions, and miscellaneous injuries of the mare's urogenital tract.

Although they are pivotal events in the continued production of new generations of horses, breeding and foaling are not without risk to the mare. This article reviews the accidents that can occur and result in injury, displacement, and malpositions of the urogenital tract of the mare.

Intestinal Healing and Methods of Anastomosis

Optimal intestinal healing occurs when like layers of the intestinal wall are aligned. Hand-sewn, double-layer, end-to-end anastomosis that apposes the mucosa and produces slight inversion of the seromuscular layer is recommended to minimize adhesion formation and provide reasonable alignment of the intestinal layers. Stapled, everted, triangulated, end-to-end anastomosis is not recommended because of extensive adhesion formation and poor healing of the intestinal layers. The preferred stapled techniques create an inverting, side-to-side stoma between the bowel segments.

Exercise-induced pulmonary hemorrhage

Exercise-induced pulmonary hemorrhage (EIPH) is characterizedby the presence of blood in the tracheobronchial airways after exercise. Most breeds used for strenuous exercise are affected. The prevalence of EIPH, irrespective of geographical location, has been reported to vary from 30% in Standardbred racehorses to 70% in Thoroughbred horses used for racing, jumping, eventing, steeplechase and polo. In addition to endoscopic confirmation, pulmonary hemorrhage can be recognized by identification of hemosiderophages (macrophages containing intracytoplasmic hemosiderin) in aspirates of tracheobronchial secretions. Detailed examinations of lungs from horses with a confirmed history of EIPH have identified certain consistent morphologic features that provide strong circumstantial evidence for bronchial arterial bleeding. Evidence of pulmonary hemorrhage is characteristically seen in the dorsocaudal regions of the caudal lung lobes. Stained a light brown-bronze color these regions are symmetrically distributed and in the inflated lung have a fine reticular pattern. The subpleural bronchial arteries are more prominent and appear enlarged and more tortuous in stained regions of the lung. Subgross examination of transverse slices of the caudal lung suggest that the hemorrhage occurs primarily in the dorsal bronchopulmonary segments with the dorsobasal bronchopulmonary segment being most severely involved. Affected regions have gross evidence of small airway disease with increased bronchial arterial supply around these airways and within the parenchyma. On microscopy, affected parenchymal regions have extensive interstitial fibrosis. Large accumulations of hemosiderophages are located within airspaces, terminal airways and within the increased connective tissue around airspaces and airways. Microangiographs of lung sections perfused with latex and barium sulfate revealed marked proliferation of the bronchial arterial circulation in lung regions with evidence of pulmonary hemorrhage. The expanded vascular network appeared to be focused on diseased small airways.

FACILITATION OF ASIAN ELEPHANT (ELEPHAS MAXIMUS) STANDING IMMOBILIZATION AND ANESTHESIA WITH A SLING

Abstract An Asian elephant (Elephas maximus) required general anesthesia for orthopedic foot surgery. The elephant was unable to lie down, so it was placed in a custom-made sling, administered i.m. etorphine hydrochloride in the standing position, and lowered to lateral recumbency. General anesthesia was maintained with isoflurane administered through an endotracheal tube. After surgery, the isoflurane anesthesia was terminated, with immobilization maintained with additional i.v. etorphine. The elephant was lifted to the vertical position, and the immobilizing effects of etorphine were reversed with naltrexone. The suspension system and hoist for the sling were designed specifically for the elephant house.

The effect of doxapram-induced hyperventilation on respiratory mechanics in horses

To investigate the influence of increased respiratory frequency on respiratory mechanics in the horse, measurements were made in two groups of seven tracheostomized horses before and after the administration of doxapram. The horses in group I had normal base line values for respiratory mechanics, whereas the horses in group II had significantly lower values of dynamic compliance (Cdyn), higher respiratory resistance (R), and a higher total change in pleural pressure (delta P). The administration of 0.3 mg kg-1 doxapram intravenously resulted in a significant increase in respiratory frequency (fR), R, delta P, tidal volume (VT), and peak to peak respiratory flow (V), and a decrease in Cdyn in both groups of horses. The group II horses had significantly greater increases in R and delta P than the horses in group I.

Perspectives on animal analgesia.

Animal welfare issues engender lively discussion, vigorous debate, and often reveal polar opinions. Well being, comfort, and pain are central topics in the conversation surrounding human interaction with animals whether as a food source, or as working or companion animals. Surgery is the nexus for one facet of this dialog. Progress in understanding the physiology of pain, and in particular the amelioration of pain, has profoundly influenced surgical practice. Whereas approaches to analgesia differ and are to some extent influenced by the target species, there is nevertheless general agreement about the importance of perioperative pain management in optimizing anesthesia, patient comfort, healing, and convalescence. Titrating pain medication to achieved a desired effect can be challenging in people and is even more complex in our animal patients. Beyond empiricism and clinical judgment, what evidence do we have for the efficacy of the drugs we select for perioperative pain management in an individual patient or for a specific type of surgical procedure and its anticipated postoperative course? Experimental studies and clinical trials using pain scoring systems are two methods used to develop the evidence that frames the foundation for clinical practice. Recently, the question of the journals’ philosophy on including negative controls in veterinary clinical trials of perioperative pain management was raised by investigators interested in submitting a report to Veterinary Surgery. In developing a response, it became apparent that within our veterinary surgical community, there were divergent, if not polar, opinions on the question. One cohort of responses argued that not providing pain relief was contrary to the standard of care, if not malpractice, whereas others reasoned that establishing a standard of care requires objective evidence of efficacy, which in turn requires reliable objective methods for assessing pain in our animal species. Our veterinary anesthesia colleagues are engaged in similar discourse and varied opinions stimulated an editorial for publication in Veterinary Anesthesia and Analgesia. Surgeons need to be active participants in this discussion, so it seemed timely to simultaneously publish the editorial in the July issue of both journals. The accompanying editorial is not intended as a reflection of journal policy or philosophy but rather a catalyst for reflection and discourse.

Academic Veterinary Surgery: An Imperiled Future?

THE CURRENT exodus of specialists from academic practice in North America continues seemingly unabated. Complex issues underpin this phenomenon, but key catalysts are unprecedented private sector demand for specialists, financial opportunity, lifestyle, access to sophisticated diagnostics, and arguably, generational discord with arcane academic expectations. As institutions and teaching hospitals struggle to adjust and respond, a larger concern looms. Traditionally, academic practice has been the primary resource for disciplinary growth. In particular, it has been the source for most new knowledge that fuels the evolution of, and advances in, a clinical discipline. The continued erosion of academic clinical staffing is having profound effects on training and knowledge generation. Veterinary surgery, particularly small animal surgery, is not unique in this dilemma. Chronic shortages of specialists in veterinary anatomic and clinical pathology, toxicology, oncology, ophthalmology, diagnostic imaging, and clinical nutrition are equally sobering. Academic institutions have been the historical incubator for residency training programs. Specialty certification training requirements appropriately prescribe ratios of mentors to trainees. With few exceptions, most institutions have not increased positions for specialist training, so loss of faculty has compounded the problem by further limiting training opportunities. In some disciplines, large private referral centers have responded by developing residency training programs to meet their own needs. In 2007, for the first time in veterinary surgery, the number of private practice residency training programs, but not training positions, exceeded the number of academic based training programs. Should we be concerned? One of the remarkably gratifying outcomes of specialty colleges like ACVS and ECVS is that they have fully realized the visions of their founding Diplomates. The current problems reflect the wisdom and success of that vision and the extraordinary dedication of a continuum of Diplomates to ensure its realization. It also echoes the undeniable success of the academic incubator. New challenges can be resolved with equal inspiration and dedication. The growth of private practice residencies is laudable and should be encouraged just as academic practice adjusts to its new challenges and evolves. These are not isolated events and creative partnerships between academic practice and private practice are critical to nurture a robust, evolving surgical discipline. There are many aspects of this relationship that need to be explored and the leadership of ACVS is proactively tackling these through a series of taskforces. Individual Diplomate participation in these efforts is essential to define a continuing vision for our college. One of the three objectives of the ACVS is ‘‘the encouragement of its members to pursue original investigations and to contribute to the veterinary literature.’’ From an editorial and scientific perspective, I am deeply concerned about the impact of academic faculty losses on knowledge generation for our specialty. It has the potential to imperil our future. Most of these former faculty were highly motivated by curiosity and the thrill of discovery, and contributed substantially to new surgical knowledge. Perhaps it is too early to gauge, but initial impressions suggest that the demands of private practice have substantially limited their continuing intellectual contributions to surgical knowledge, at least through peer-reviewed publication, which arguably remains the legitimate currency of most scientific advances. This is not an indictment of those individuals but rather a wake-up call to all of us to reconsider not only the importance of discovery, but the value of its impartial communication to our colleagues and the larger community of scientists and pet owners. Private referral practice represents a vastly under utilized resource for new knowledge whether affirming, reaffirming, or refuting the validity of current surgical practices, or developing new approaches for improved surgical care of our patients. As the number of private sector residency training positions increases, it will be critical for the specialty colleges to ensure that resources that facilitate generation, and critical assessment, of knowledge are fostered. The publication requirement for eligibility for specialty certification remains a strong stimulus for knowledge generation but more is required. Tools and training need to be developed for program directors, mentors, and trainees, to facilitate clinical trials and original clinical research in private practice, and where appropriate, partnerships with academic colleagues to pursue more basic surgical research.