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Biomedical subjects

Pamela A Wilkins

Publications and source records attributed to Pamela A Wilkins.

At least 19 recordsLinked to original sources

Congenital vulvar deformity in 6 alpacas.

CASE DESCRIPTION: 6 female alpacas, ranging in age from < 1 day to > 2 years, were examined because of primary owner complaints related to urogenital malformation. CLINICAL FINDINGS: In all instances, the vulva was totally to subtotally imperforate. One neonate had failure of passive transfer of immunity and mild azotemia at the time of initial examination. No additional urogenital malformations were detected in any of the alpacas. TREATMENT AND OUTCOME: Vulvoplasty performed via local anesthesia was successful in all alpacas. The neonate with failure of passive transfer received a plasma transfusion. Postsurgical wound management was limited to topically applied medications. CLINICAL RELEVANCE: Congenital vulvar deformity in alpacas may result in interference with urine outflow. Neonates with a completely imperforate vulva may be brought to veterinarians for examination on an emergency basis. Less severely affected alpacas may be examined later in life with owner complaints ranging from stranguria or dysuria to urogenital malformation. No other primary abnormalities of the urogenital tract in alpacas have been reported, to the authors' knowledge. Vulvoplasty, performed with local anesthesia, resolves obstructed urine flow. Because it is possible that this condition is heritable, affected alpacas, and possibly their sires and dams, should not be used for breeding.

Animals↗

Advanced techniques in the diagnosis and management of infectious pulmonary diseases in horses.

Techniques for novel approaches to the diagnosis and management of equine pulmonary disease continue to be developed and used in clinical practice. Diagnostic techniques involving immunoassays and nucleic acid-based tests not only decrease the time in which results become available but increase the sensitivity and specificity of test results. These assays do not substitute for careful clinical evaluation but can shorten the time to a confirmed accurate diagnosis, and thus allow for early initiation of therapeutic strategies and prevention protocols. With further understanding of the molecular biology and immunology of equine pulmonary disease, diagnostic and management techniques should become further refined.

Animals↗

Margins and outcome of screen-detected breast cancer with extensive in situ component.

BACKGROUND: In situ disease surrounding invasive tumours is an important consideration in the management of patients with early breast cancer. This study of screen-detected breast cancers assessed the influence of in situ disease including an extensive in situ component (defined as ductal carcinoma in situ involving more than 25% of the area within the invasive tumour) on surgical management, local recurrence and survival of a group of patients. METHODS: A total of 595 cases of invasive breast cancer detected at St Vincent's BreastScreen were retrospectively reviewed to determine presence and extent of in situ disease, the surgical procedure and adequacy of excision. Outcome was examined in a cohort of 126 cases. RESULTS: A total of 438 (74%) patients had in situ foci in or around the invasive tumour and 107 (18%) were defined as extensive in situ component (EIC)-positive. The initial procedure was mastectomy in 20% of the cases and breast-conserving surgery in 80% including 18% who underwent further surgery. Re-excision (P = 0.02) or mastectomy (P = 0.01) was more often required in patients with EIC. After definitive local excision, margins were close or involved with invasive disease in 3% but the patients with EIC were more likely to have margins close or involved with in situ disease (16 vs 2%; P = 0.001). There were seven deaths and one local invasive recurrence in the follow-up group and none of the deaths were in patients who were EIC-positive. CONCLUSIONS: EIC predicts for a higher rate of re-excision and/or mastectomy. For patients with EIC, there is an acceptably low risk of local recurrence if margins are clear.

Adult↗

Rupture of the gastrocnemius muscle in six foals.

Rupture of the gastrocnemius muscle and subsequent disruption of the reciprocal mechanism of the hind limb was diagnosed in 6 foals examined at 7 hours to 3 weeks of age. In 2 foals, the musculoskeletal injury was detected as an ancillary finding to clinical signs of neurologic dysfunction ascribed to hypoxic ischemic insult during delivery, whereas in the other 4 foals, musculoskeletal injury, manifested as inability to rise or stand unsupported, was the chief complaint at admission. Five foals had a history of dystocia and assisted delivery. Common clinical signs were inability to rise, disruption of the reciprocal mechanism, swelling in the caudal aspect of the thigh, instability of the stifle joint, and stifle joint effusion. For mild gastrocnemius injury, exercise restriction via forced recumbency, with minimal or no bandaging, may be sufficient treatment. For more severe disruption of the muscle, limb stabilization via splinting and intensive nursing and monitoring are necessary. Four foals had important concurrent problems, including musculoskeletal deformations (joint contractures), hypoxic ischemic disease, and failure of passive transfer and associated problems (ie, sepsis, polyarthritis, and pneumonia). Moderate to severe gastrocnemius muscle injury is difficult to treat successfully, and the long-term prognosis for athletic function should be regarded as guarded.

Animals↗

Comparison of thermal dilution and electrical impedance dilution methods for measurement of cardiac output in standing and exercising horses.

OBJECTIVE: To compare cardiac output measured in the pulmonary artery and a carotid artery by use of thermal and electrical impedance dilution. Animals-7 fit, clinically normal Standardbreds between 2 and 5 years of age. PROCEDURE: Transient changes in electrical impedance and temperature of blood were induced by bolus injections of ice-cold saline hypertonic (6% and 9% NaCl) solutions. Cardiac output was calculated by applying Stewart-Hamilton principles to the indicator dilution transients. Measurements were made during sequential exercise episodes on a level treadmill over approximately an 8-fold range of cardiac output values. RESULTS: We detected agreement between cardiac output determined by use of electrical impedance dilution at the pulmonary artery and carotid artery. Cardiac output from thermal dilution measured at the carotid artery exceeded that measured at the pulmonary artery. Cardiac output from the thermal dilution technique exceeded cardiac output from the electrical impedance dilution technique at both locations. CONCLUSIONS AND CLINICAL RELEVANCE: The electrical impedance indicator is conserved on first transit; therefore cardiac output measured by electrical impedance dilution at the carotid artery is reliable over a large range of values. Thermal dilution provides a larger estimate of cardiac output, compared with the electrical impedance dilution technique, probably because of a loss of indicator. The transpulmonary electrical impedance dilution technique may have potential for clinical application, particularly in animals in which catheterization of the pulmonary artery is not appropriate or blood loss must be minimized.

Animals↗

Acute respiratory distress syndrome.

Several combination therapies have been described throughout this article: in all likelihood, it is combination therapy that will allow improved survival of ARDS patients. As medicine moves into the future, clinical trials evaluating the efficacy of therapies for ARDS will be performed. In human critical care medicine, a large forward step was taken when ALI and ARDS were clearly defined. Unfortunately. as good as the definition is, ALI and ARDS occur secondary to many different underlying pathologic processes,perhaps obscuring the benefits of certain therapies for ARDS based on the underlying condition, for example, trauma versus sepsis. Selection of patients entering any ARDS trial is crucial: not only must those patients meet the strict definition of ARDS but the underlying disease process should be clearly identified. Identification of patients suffering from different disease processes before the onset of ARDS will allow for stratification of outcomes according to the intervention and the underlying pathology--comparing apples to apples and not to oranges. We are in a unique position in veterinary medicine. Although frequently financially limited by our clients, we have the opportunity to achieve several goals. First, we need to clearly define what constitutes ALI and ARDS in veterinary medicine. Do we want to rely on the human definitions? Probably not; however, as a group, we need to determine what we will accept as definitions. For example, we may not be able perform right heart catheterizations on all our patients to meet the wedge pressure requirement of human beings of less than 18 mm Hg. Do we agree that a PAOP of less than 18 mmHg is appropriate for animals, and is it appropriate for all animals? Will we accept another measure, for example, pulmonary artery diameter increases with echocardiographic evidence of acceptable left heart function? What is acceptable left heart function? As veterinarians, what do we consider to be hypoxemia? Is it the same in all species that we work with? What do we define as acute onset? Most human ARDS cases occur while patients are in hospital being treated for other problems, whereas many of our patients present already in respiratory distress. If we are unable to ventilate patients for economic or practical reasons, what do we use as the equivalent of the Pao2/Flo, ratio'? Reliance on the pathologist is not reasonable, because many disease processes can look similar to ARDS under the microscope. If anything, ALI and ARDS are clinical diagnoses. It is time for veterinarians to reach a consensus on the definition for ALI and ARDS in our patients. Only when we have a consensus of definition can rational prospective clinical trials of therapies be designed.

Animals↗

Nutrition and the critically ill horse.

A nutritional plan should be incorporated into every treatment plan of the critically ill patient. Weight loss and cachexia are the result of prevalence of catabolic processes over anabolic processes in addition to absolute or relative increased demands and decreased food intake.

Animal Nutritional Physiological Phenomena↗

Lower respiratory problems of the neonate.

The newborn foal can experience problems of the lower respiratory tract that are unique to the neonate. The transition to extrauterine life usually occurs rapidly and in a coordinated manner, but problems associated with the peripartum period, including placentitis, dystocia, infection, and trauma, can result in conditions that compromise gas exchange in the newborn foal. This article reviews the normal transition and presents some of the problems seen in these small patients.

Adaptation, Physiological↗

Lower airway diseases of the adult horse.

Lower airway problems of the adult horse are commonly encountered by the practitioner. Particularly susceptible populations include horses transported for any significant distance and young horses grouped together for training and/or competition. This article presents some of the commonly encountered problems of this patient population, including bacterial pneumonia/pleuropneumonia and influenza, and some uncommon ones, including pulmonary edema, pneumothorax/hemothorax, and acuterespiratory distress syndrome. Information is presented that should allow the practitioner to diagnose these problems accurately and initiate rational treatment plans.

Animals↗

Clinicopathologic evidence of disseminated intravascular coagulation in horses with acute colitis.

OBJECTIVE: To detect subclinical disseminated intravascular coagulation (DIC) in horses with colitis and to determine any association between the diagnosis of subclinical DIC and outcome or occurrence of complications in horses with colitis. DESIGN: Prospective study. ANIMALS: 37 horses admitted to a veterinary teaching hospital for treatment of acute colitis. PROCEDURE: Coagulation profiles were obtained on each horse 0, 24, and 48 hours after admission. Six tests were performed: platelet count, plasma fibrinogen concentration, prothrombin time, activated partial thromboplastin time, antithrombin activity, and serum fibrin degradation products concentration. RESULTS: A clinicopathologic diagnosis of subclinical DIC was made if 3 of the 6 tests had abnormal results at any 1 sample period. No horse had clinical signs of DIC at the time of sampling. Twelve of 37 (32%) horses met the criteria for diagnosis of subclinical DIC within a 1-year period. Outcome was defined as survival or nonsurvival. Five of 12 horses with subclinical DIC and 2 of 25 horses without subclinical DIC did not survive. Crude odds ratio analysis revealed a horse with acute colitis was 8 times as likely to die or be euthanatized if a diagnosis of subclinical DIC was made. CONCLUSIONS AND CLINICAL RELEVANCE: Clinicopathologic evidence of DIC is common and is significantly associated with a poor outcome in horses with acute colitis. Treatment of subclinical DIC may influence outcome in horses with acute colitis.

Acute Disease↗

Life-threatening hemorrhage from enterotomies and anastomoses in 7 horses.

OBJECTIVE: To report our experience with horses that presumptively had severe intraluminal hemorrhage from enterotomy or anastomosis. STUDY DESIGN: Clinical study. ANIMALS: Six adult horses and 1 adult donkey. METHODS: A retrospective study was conducted at the University of Illinois (April 1994 to December 2001) to determine the clinical course and outcome of horses with melena and/or anemia and evidence of life-threatening hemorrhage from intestinal incisions. Medical records of all horses that had colic surgery were reviewed to determine the proportion of horses with this complication. In addition, horses that fit the same criteria identified in 3 other veterinary clinics were included. RESULTS: Three horses (1.3%) of those that had enterotomy or anastomosis at the University of Illinois and 4 horses from other clinics had complications presumptively related to severe hemorrhage from these intestinal procedures. Melena became evident within 72 hours of surgery and lasted 12 to 96 hours. Six horses had an acute and severe drop in packed cell volume (PCV), increased heart rates, and other signs of acute hemorrhage, and 1 horse had signs of colic postoperatively. Horses were administered intravenous formalin (3 horses) and whole blood transfusions (4 horses). Repeat celiotomy was performed on 2 horses. In 1 of these horses, a bleeding artery was ligated in the edge of the original enterotomy, and, in the other, a 25-cm-diameter intraluminal blood clot was found occluding the pelvic flexure. A horse that had jejunocolostomy for cecal impaction was not treated for hemorrhagic shock but was euthanatized and necropsied. Necropsy revealed blood-filled bowel from the jejunocolostomy to the anus. One of the remaining 6 horses died of enterocolitis and 5 survived to discharge. CONCLUSIONS: Hemorrhage from incisional edges, particularly in the large intestine, should be considered a rare but possibly fatal complication of enterotomy or anastomosis in horses. CLINICAL RELEVANCE: To prevent fatal hemorrhage from incisional edges during enterotomy or anastomosis, large vessels should be ligated at the original surgery, and hemostatic effects of different closure techniques should be considered. No intraoperative or postoperative findings were useful to predict this complication, and response to supportive medical therapy was favorable.

Anastomosis, Surgical↗

Multiple rib fracture in a neonatal foal using a nylon strand suture repair technique.

OBJECTIVES: To report rib fracture repair using the Securos Cranial Cruciate Ligament Repair System (SCCLRS; Securos Veterinary Orthopedics, Charlton, MA) in a neonatal foal. STUDY DESIGN: Case report. ANIMALS: A 1-day-old Standardbred foal with fracture of left ribs 2-9. METHODS: Four days after admission the foal was anesthetized and rib fractures were repaired using open reduction and the SCCLRS. RESULTS: Rib fractures were successfully stabilized and the foal was discharged 7 days postoperatively without further complications. CONCLUSIONS: The SCCLRS provided a straightforward, effective method of rib fracture repair in neonatal foals. CLINICAL RELEVANCE: Effective rib fracture repair in neonatal foals can be achieved with the SCCLRS.

Animals↗

Botulism in foals less than 6 months of age: 30 cases (1989-2002).

Botulism has been recognized as a clinical entity in foals since the 1960s. Also known as "Shaker foal" disease, the toxicoinfectious form of botulism affects foals, with the highest incidence in the United States seen in Kentucky and the mid-Atlantic region. The disease is characterized by progressive muscular weakness caused by the action of botulism neurotoxin at cholinergic neuromuscular junctions. Increased number of episodes and duration of recumbency, muscular trembling, and dysphagia are seen in affected foals. Left untreated, the disease can be rapidly fatal, with death occuring secondary to respiratory muscle paralysis within 24 to 72 hours of the onset of clinical signs. Very mildly affected foals can survive with minimal treatment Despite advances made in treatment of these foals, including administration of botulism antitoxin early in the course of the disease, there is still an impression that the disease carries a high mortality rate. The purpose of this study was to evaluate outcome in 30 foals <6 months of age diagnosed with botulism between 1989 and 2002 at the George D. Widener Large Animal Hospital, New Bolton Center. Two foals were euthanized for economic reasons early in the disease course, and I died while being treated. Survival of treated cases was greater than 96%. Approximately 50% of the cases required oxygen therapy, whereas 30% required mechanical ventilation. All foals, excepting 1 mildly affected foal, received botulism antitoxin. Mean duration of hospitalization was 14 days. With appropriate treatment, foals with botulism have a high survival rate.

Animals↗

Hemangiosarcoma in 11 young horses.

Hemangiosarcoma is a rare neoplasm of horses and hemangiosarcoma in young horses might behave differently than in mature horses. The purpose of this study was to identify the characteristics of hemangiosarcoma occurring in horses < or = 3 years of age. Medical records from 1982 to 2004 were searched for horses < or = 3 years of age with a histopathologic diagnosis of hemangiosarcoma. Eleven records were identified. Thoroughbred and Thoroughbred crosses predominated. Age ranged from 9 days to 3 years. All horses presented with cutaneous or leg swellings or joint effusion. Physical examination findings included tachycardia, fever, and depression. Laboratory abnormalities included anemia (5/11), hyperfibrinogenemia (4/11), hypofibrinogenemia (3/11), thrombocytopenia (2/11), and neutrophilic leukocytosis (1/11). Ultrasonographic and radiographic evaluation was not diagnostic in any case. Antemortem histopathologic diagnosis was obtained in 10 cases. Six of 11 horses were euthanized. Surgical resection was performed in 5 horses, 2 of which were later euthanized. Diagnosis was confirmed histologically at postmortem examination in all euthanized horses. Two cases resolved spontaneously. Early histopathologic diagnosis may allow cure if the mass is localized and amenable to surgical resection. In cases where the horse is medically stable, and masses are not interfering with quality of life, a period of observation may be warranted.

Age Factors↗