Assessment of clinical reasoning skills in veterinary students prior to and after the clinical year of training

OBJECTIVE: To examine the effect of various clinical tracks within the veterinary medical clinical curriculum at Texas A&M University on clinical diagnostic proficiency as determined by pre- and post-training assessment. We expected that the clinical track chosen by the student would impact their measured outcome with bias toward higher scores in their chosen field. DESIGN: Prospective cohort study. STUDY POPULATION: 32 students from the College of Veterinary Medicine and Biomedical Sciences at Texas A&M University. PROCEDURES: By use of standardized, written case scenarios, clinical reasoning was assessed twice: once prior to the clinical (fourth) year of the curriculum and again at completion of the clinical year. Students demonstrated their abilities to collect and organize appropriate clinical data (history, physical examination, and laboratory findings), determine clinical diagnoses, and formulate and implement acceptable treatment modalities. Data from clinical assessments were compared for a given cohort and correlated with other measures (eg, grades, standardized test scores, and species-specific curricular track). RESULTS: Differences were detected in clinical diagnostic proficiency among students in different clinical tracks and for different species groups in the case scenarios. Tracking by species group in the clinical veterinary curriculum appeared to affect development of clinical reasoning and resulted in differential proficiency among cases for differing species groups. CONCLUSIONS AND CLINICAL RELEVANCE: Differences in clinical experiences between small animal tracks and all other track opportunities (large animal, mixed animal, and alternative) influenced the development of clinical proficiency in fourth-year veterinary students during their clinical training period.     

The Objective Structured Clinical Examination (OSCE) as a determinant of veterinary clinical skills

The Objective Structured Clinical Examination (OSCE) has become an excellent tool to evaluate many elements of a student's clinical skills, especially including communication with the patient (human medicine) or client (veterinary medicine); eliciting clinical information from these conversations; some aspects of the physical examination; and many areas of clinical evaluation and assessment. One key factor is that the examination can be structured to compare different students' abilities.     

Increased pulmonary activation of nuclear factor-kappaB (NF-kappaB) in foals inoculated with Rhodococcus equi is associated with increased expression of inflammatory cytokines

Previous studies revealed that foals inoculated with virulent Rhodococcus equi had significantly higher pulmonary levels of interleukin-1beta, interleukin-12 p40, interferon-gamma, and tumor necrosis factor-alpha mRNA compared to foals inoculated with an avirulent plasmid-cured derivative. The purpose of this study was to determine if the increases in cytokine expression were associated with increased pulmonary activation of nuclear factor-kappaB (NF-kappaB). Electrophoretic mobility shift assays were performed on pulmonary nuclear protein extracted from foals treated with phosphate-buffered saline, or inoculated with either virulent or avirulent R. equi. NF-kappaB activation was increased in the nuclear extracts from foals inoculated with virulent R. equi at 14 days after inoculation when increased cytokine expression was also observed. Southwestern histochemistry revealed activated NF-kappaB in multinucleated giant cells that often contained bacteria. These results indicate that the cytokine response to R. equi is at least partially mediated by NF-kappaB activation.     

Increased free cortisol in plasma of dogs with portosystemic encephalopathy (PSE)

Dogs with portosystemic encephalopathy (PSE) are known to develop pituitary-dependent hyperadrenocorticism, but there have been no reports on the plasma protein binding of cortisol in these dogs. Since the liver is involved in the synthesis of corticosteroid-binding globulin (CBG) and other transport proteins for cortisol, the binding characteristics of these proteins and thus the biologically-active free fraction of cortisol might be altered in dogs with PSE. We investigated the total concentration of cortisol and the free fraction and the free cortisol concentration in plasma of thirty-two dogs with PSE due to inherited portosystemic shunts or chronic active hepatitis with cirrhosis. We found a significantly higher free fraction (14.7 ± 5.8%, P<0.0001) and free cortisol concentration (26.3 ± 23.1 nM, P<0.001) in these dogs than in healthy controls (8.2 ± 2.3% and 9.2 ± 7.2 nM, respectively). Moreover, basal concentrations of total cortisol in the dogs with PSE were higher than in the healthy controls (190 ± 146 nM v. 107 ± 65, P<0.01). The per cent free cortisol in plasma was not significantly correlated with the concentration of albumin or the total cortisol in plasma. We conclude that there is decreased binding of cortisol in plasma of dogs with PSE due to decreased hepatic synthesis of cortisol binding proteins. The presence of increased concentrations of free cortisol in these dogs indicates that their basal pituitary-adrenocortical activity was increased, probably due to aberrant neurotransmission in brain centers associated with pituitary function, as a result of hepatic encephalopathy.     

Evolution of a course in veterinary clinical pathology: the application of case-based writing assignments to focus on skill development and facilitation of learning

RATIONALE FOR STUDY: To encourage application and critical thinking, case-based writing assignments and grading rubrics were developed for use in a second-year core clinical pathology course. Objectives were to describe how this teaching technique was adapted to a large-class setting and how student perceptions of the learning experience guided modifications of this teaching technique over two presentations of the course and plans for a third presentation. Our goal was to enhance learning by encouraging application of course material to clinical situations and thereby improve students' ability to organize and communicate information. Furthermore, we evaluated the influence of instructor feedback on the learning process. METHODS: With assistance from the University of Minnesota Center for Writing, assignments and grading rubrics were developed. Students completed course evaluation surveys designed to elicit feedback on the impact of the assignments. RESULTS: Increased learner confidence was reflected in larger self-reported increases in understanding of the material and ability to apply information and in increased feelings of preparedness for class and examinations. A large majority of students advocated the use of such assignments in the course in future years, and modifications to make grading and evaluation of assignments more efficient are underway. CONCLUSIONS: Investment of faculty and student time in case-based writing assignments in the veterinary clinical pathology curriculum appears to increase student engagement with material and learner confidence. Future studies should address the impact of this type of assignment more specifically on clinical reasoning and communication skills and on long-term retention of material.     

Hepatotoxicity associated with CCNU (lomustine) chemotherapy in dogs

One hundred seventy-nine tumor-bearing dogs were treated with 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) between 1995 and 2001. CCNU was given as a single dose of 50-110 mg/m2 body surface area PO. Treatment interval varied, but the minimal interval between CCNU doses was 3 weeks. After treatment, 11 dogs (6.1%) developed hepatic toxicity. The median number of CCNU doses and the median total cumulative CCNU dose were significantly higher in dogs that developed hepatic toxicity (4 doses; 350 mg/m2) than in dogs without hepatic damage (3 doses; 230 mg/m2). Median duration to detection of hepatic toxicity from the last dose of CCNU was 11 weeks (range 2-49 weeks). Common biochemical abnormalities were abnormally high serum liver enzyme activities and hypoalbuminemia. Six dogs with CCNU-associated hepatic toxicity had ascites, and 3 dogs had concurrent pleural effusion. Serum concentrations of bile acids were abnormally high in 4 of 5 dogs tested. Percutaneous ultrasound-guided liver biopsies were performed in 10 dogs, and findings were nonspecific and chronic in nature. Seven dogs were euthanized because of progressive liver failure, and their median survival from diagnosis of liver disease was 9 weeks. Three dogs died of other causes and 1 dog of unknown cause. Although clinical signs resolved in 3 dogs, biochemical abnormalities and histopathologic lesions persisted 4 to 38 months from the time of diagnosis of liver disease. Our findings suggest that CCNU can cause delayed, cumulative dose-related, chronic hepatotoxicity that is irreversible and can be fatal.     

Dermatitis associated with microfilariae (Filarioidea) in 10 dogs

Dermatitis associated with microfilariae of a nematode of the superfamily Filarioidea was diagnosed in 10 dogs from the western United States. Clinically, lesions were single or multiple papules and plaques with alopecia, scarring, erythema, ulceration, or crusting. Eight dogs had lesional pruritus. Microscopically, there was perivascular, periglandular, to interstitial inflammation, with many eosinophils and/or plasma cells, and scarring affecting the dermis and subcutis. Microgranulomas containing microfilaria were seen in six dogs. Microfilariae were noted in microgranulomas or free in the dermis or subcutis, but not in vessels. In one case, an adult female nematode emerged from a biopsy sample that was placed in physiologic saline. Study of this nematode revealed that it was a filarioid of the family Onchocercidae; it was identified as Acanthocheilonema sp. (syn: Dipetalonema ). Antigen tests of five dogs were negative for Dirofilaria immitis . The Knott tests and/or filter tests of nine dogs were negative for microfilariae. An indirect fluorescence antibody test of one dog was also negative for D. immitis . One dog was not evaluated for microfilariae.     

Pathogens associated with mammalian embryo (a review)

The advantages of transporting mammalian preimplantation embryos rather than postnatal living animals include reduced costs of transportation and rapid dissemination of genetic material between countries. However, the risk of transmission of diseases through the embryos must be considered. The disease control potential of embryos will depend on proper handling and washing, and the integrity of zona pellucida. Researches on embryo-pathogen interactions have shown that some pathogens are carried through the gametes and others could not infect the gametes. Some pathogens were found to adhere to the zona pellucida and others could penetrate the zona pellucida. To date, data presented appear to suggest no concrete model guidelines for embryo-pathogen interaction. The interaction seems to depend on the species and the pathogen involved.     

Ketosis in buffalo (Bubalus bubalis): clinical findings and the associated oxidative stress level

As little is known about the oxidant/antioxidant status in buffalo with ketosis, the present study was delineated to assess the oxidative stress level associated with clinical ketosis in water buffalo. A total of 91 parturient buffalo at smallholder farms were studied (61 suspected to be ketotic and 30 healthy). Clinical and biochemical investigations were carried out for each buffalo. Based on clinical findings and the level of beta-hydroxybutyrate (BHB), buffalo were allocated into ketotic (42), sublinical cases (19). Clinically, there was an association between clinical ketosis and anorexia (p < 0.001), constipation (p < 0.001), decreased milk yield (p < 0.001), ruminal stasis (p < 0.001), and loss of body condition (p < 0.01). Biochemically, in clinical ketosis compared with subclinical and control cases, there was a significant increase (p < 0.05) of BHB, malondialdehyde (MDA), nitric oxide (NO), aspartate aminotransferase (AST), L-alanine aminotransferase (ALT). However, there was a significant decrease of glucose, phosphorus, magnesium,total cholesterol and HDL-cholesterol. There was a positive correlation between BHB and MDA (r = 0.433), BHB and NO (r = 0.37), MDA and NO (r = 0.515), and Glucose and phosphorus(r = 0.521). However, there was a negative correlation between BHB and glucose (r = −0.341) and HDL and NO (r = −0.379). The result of the present study indicates that hyperketonemia in buffalo is associated with an increase of oxidative stress levels. Further studies need to be done on the efficacy of antioxidants as an ancillary treatment to relief the oxidative stress caused by ketosis.     

Enterocecocolitis associated with intraepithelial Campylobacter-like bacteria in rabbits (Oryctolagus cuniculus)

We examined 28 suckling, weanling, and young adult rabbits with lethargy, inappetence, and mucinous, semifluid feces. Sixteen of the rabbits had intestinal lesions. In eight of these rabbits, the primary changes were multifocal to diffuse epithelial proliferation and accumulation of lymphocytes, macrophages, or both in the lamina propria of the small intestine, cecum, and sacculated colon. In two of these rabbits, the accumulation of macrophages in the lamina propria was extensive. The other eight rabbits had erosive and suppurative cecocolitis, and four of the rabbits with proliferative lesions also had suppurative cecocolitis. In Warthin-Starry-stained sections of affected intestine, curved or spiral bacteria were visible within degenerated or hyperplastic epithelium, in luminal exudate, or in both. Such organisms were sparse or not found in the other 12 rabbits, which did not have intestinal lesions. The bacteria ultrastructurally resembled intraepithelial Campylobacter-like bacteria previously observed in proliferative enteritis in a variety of species and in acute typhlitis in young rabbits. In immunofluorescence tests, Campylobacter-like bacteria in epithelial cells, crypt lumina, and in luminal exudates in both proliferative and erosive lesions bound monoclonal antibodies and polyclonal antisera prepared against intracellular bacteria found in proliferative enteritis in pigs, hamsters, and ferrets. These observations indicate that a condition similar to proliferative enteritis of swine, hamsters, and other species also occurs in laboratory rabbits.     

A reovirus-like agent (rotavirus) associated with diarrhoea in neonatal pigs

Reovirus-like particles were detected by electron microscopy in the faeces of pigs with diarrhoea. Attempts to adapt the virus to grow in pig kidney cell cultures were unsuccessful. By immunofluorescent staining techniques the pig virus was shown to be antigenically related to the calf rotavirus. Colostrum-deprived piglets were readily infected with the virus. Viral replication occurred in villous epithelial cells in the small intestines of infected pigs, and virus was detected in the faeces for at least 7 days post infection. All infected piglets developed diarrhoea whereas uninfected controls did not.     

Verrucous endocarditis associated with Streptococcus bovis in mink (Mustela vison)

Between 1998 and 2001, mortalities due to verrucous endocarditis were experienced at several mink farms. Gram-positive cocci were isolated from the endocardium of all the animals examined but not always from other internal organs. Almost all the isolates were identified as Streptococcus bovis and only a few isolates belonged to other Streptococcus species. Typing by pulsed-field gel electrophoresis of a selection of isolates revealed several patterns and several different clones. Attempts to reproduce disease by the injection of cultures of a field isolate into healthy mink failed.     

Myopathy in brown pelicans (Pelicanus occidentalis) associated with rancid feed

Three adult brown pelicans (Pelicanus occidentalis) were observed to be weak, anorexic and unresponsive to antibiotics, anti-inflammatory drugs, vitamins including vitamin E, and steroids. Blood chemistry revealed high activities of aspartate aminotransferase, creatinine kinase and lactate dehydrogenase. Radiographs of the birds' leg muscles revealed multiple opacities suggestive of calcification; the gross lesions included white streaks in the leg, wing, and heart muscles, and the microscopical lesions consisted of various degrees of degeneration and necrosis characterised by eosinophilia, variations in fibre size, loss of striations, myolysis, mineralisation, and proliferation of mononuclear cells in the skeletal muscles and the myocardium. The levels of heavy metals, selenium and vitamin E in the birds' livers were not abnormal. The level of peroxide in their diet of capelin fish was high, 69 meq/kg, (normal <20 meq/kg) consistent with rancid feed, and the level of vitamin E was very low, 0.5 iu/kg (normal 20 to 30 iu/kg). It was concluded that the myopathy was probably caused by vitamin E deficiency due to feeding the pelicans a rancid diet.