DEVELOPMENT OF INTERACTIVE PATIENT-BASED MULTIMEDIA COMPUTER PROGRAMS IN VETERINARY ORTHOPEDIC RADIOLOGY

Three computerized multimedia programs on large and small animal veterinary orthopedic radiology were developed and implemented for the radiology curriculum as an alternative to traditional film-based laboratory learning. Programs utilized "hot words" (colored text words that displayed an overlaid image label that highlighted lesions) and interactive quizzes which responded appropriately to selected answers. "Hot words" helped students develop confidence in accurate lesion detection and the interactive quizzes transformed learning from a passive to an active process. Multiple examples were provided for reinforcement and concepts were incorporated from other clinical disciplines for curriculum integration. Programs were written using a presentation software program, Toolbook® for DOS based platform, and contained radiographic images made by laser-scanning digitization. Multiple students could simultaneously access the programs through a network server. These pilot programs were implemented successfully and computerized multimedia presentation proved to be well suited to teaching radiology. Development of the programs required attention to a number of hardware, software, time and cost factors.     

Integrated parasite management: products for adoption by the Australian sheep industry

The increasing cost of production loss caused by gastrointestinal nematodes (GIN) highlights the importance of good control programs. However, the endemic nature of anthelmintic resistance also reminds of the need for nonchemical options. Both chemical and nonchemical control options need to be integrated into regional parasite management programs (IPM) with the emphasis on component options determined by factors such as major GIN species, regional climate, property size and enterprise structure. The Integrated Parasite Management of Sheep project was established to develop and demonstrate regional parasite control programs, that integrated chemical and nonchemical options, for the main sheep-producing regions of Australia. The project included research about the ecology of the main endo and ecto-parasites of sheep and a national survey of parasite control practices by sheep producers. IPM approaches developed for two contrasting regions of Australia are discussed. Barriers for the adoption of IPM programs include perceived complexity associated with a multi-component approach, time requirements and difficulty. Facilitating the industry adoption of IPM programs is discussed with relevance to the use of small group extension and involvement of the commercial sector. Perceptions of complexity of IPM may be managed by facilitating adoption of components in a step-wise process such that learning outcomes accumulate over time. Extension efforts must address the needs of industry sectors other than sheep producers and explore user pay approaches. The success of these approaches will depend on the relation of the extra profit to producers, through adoption of IPM programs, with remuneration sufficient to attract a commercial service.     

Cost-benefit evaluation of artificial insemination for genetic improvement of wool-producing sheep

SUMMARY The financial costs and benefits associated with the use of artificial insemination (AI) in commercial flocks are evaluated. Benefits are calculated in terms of net present values after summing the discounted value of benefits over 20 years. Two breeding strategies are evaluated. With the first, AI is used to produce flock ewes and wethers. The method is unlikely to be profitable unless high breeding value rams are available for AI programs with fresh semen. With the second, AI is used to produce home-bred rams, which in turn sire flock ewes and wethers. This approach is more likely to be profitable. The cost of AI per lamb weaned from laparoscopic AI programs is about $100. Benefits exceed this cost for rams of very high merit when wool prices are moderate or higher. Flock structure has a significant effect on the benefits. Flocks with low wether retention rates have benefits half that of flocks that retain most wethers to 6 years of age. AI with purchased semen also provides benefits to risk management for owners of commercial flocks who wish to breed their own replacement flock rams.     

Unknown‐parent groups in single‐step genomic evaluation

In single‐step genomic evaluation using best linear unbiased prediction (ssGBLUP), genomic predictions are calculated with a relationship matrix that combines pedigree and genomic information. For missing pedigrees, unknown selection processes, or inclusion of several populations, a BLUP model can include unknown‐parent groups (UPG) in the animal effect. For ssGBLUP, UPG equations also involve contributions from genomic relationships. When those contributions are ignored, UPG solutions and genetic predictions can be biased. Options to eliminate or reduce such bias are presented. First, mixed model equations can be modified to include contributions to UPG elements from genomic relationships (greater software complexity). Second, UPG can be implemented as separate effects (higher cost of computing and data processing). Third, contributions can be ignored when they are relatively small, but they may be small only after refinements to UPG definitions. Fourth, contributions may approximately cancel out when genomic and pedigree relationships are constructed for compatibility; however, different construction steps are required for unknown parents from the same or different populations. Finally, an additional polygenic effect that also includes UPG can be added to the model.     

Differentiating between analytical and diagnostic performance evaluation with a focus on the method comparison study and identification of bias

Prior to introduction of a new method to the diagnostic laboratory, analytical performance must be validated to ensure operation within the manufacturer's specifications and/or within predetermined quality requirements. In addition, the new method may require diagnostic performance assessment to ensure it differentiates between diseased and nondiseased individuals as intended. These 2 phases of assessment, while complementary, are not equivalent and require a different set of experiments, statistical analyses, and interpretation. Studies of analytical performance typically include a method comparison experiment, the purpose of which is to identify bias (inaccuracy) of the “test” (or “index”) method (new method) relative to a “comparative method” (established method). Analysis of method comparison data is facilitated by commercial software programs that present the statistical significance of identified bias; however, the clinical relevance of any bias also should be considered. Studies of diagnostic performance should not be pursued until analytical performance is fully characterized and may not be required for well‐established tests or for those for which results are nonspecific (ie, not referable to a specific disease or condition). Diagnostic performance assessment may include assessment of sensitivity, specificity, predictive values, odds ratios, and/or likelihood ratios. The purpose of this review is to clarify differences between the assessment of analytical and diagnostic performance, and to explore the method comparison study and bias assessment from a perspective not addressed in prior veterinary articles.     

Animal health surveillance: navigation amidst the flotsam of human frailty and fiscal inertia

National veterinary services monitor endemic, emerging and exotic disease situations. They intervene when epidemic tendencies demand. They unravel complex disease situations. They do so as monopolies, in environments of political influence and budgetary restraint. When human, animal health and trade protection dictate, they design import or domestic disease control programs. As much as 80% of program expenditures are on surveillance. Their initiatives are scrutinized by treasuries from which they seek funding, industries from which they seek collaboration and trading partners from whom they seek recognition. In democracies, surveillance and control programs are often the products of a complicated consultative process. It involves individuals who have both a commitment to improving an existing animal health situation and access to the required resources. The generations that designed traditionally risk-averse national surveillance and control programs have given way to a new one which is more epidemiologically informed. Their successors design programs bearing epidemiologically based improvements. The transition, however, has not been overwhelmingly welcomed. Expenditures on surveillance are tolerated out of fear during outbreaks of foreign or re-emergence of indigenous disease. Between epidemics, they decline at the hands of producers' unwillingness and budgetary restraint. Human nature responds to the high cost of surveillance in forms ranging from na?veté through to conspiracy. While legislation cannot subdue such human frailty, several other opportunities exist. Education can remove the majority of problems caused by ignorance, leaving the minority that arise intentionally. Technology decreases the high cost of testing which tempts individuals to cut corners. International standards assist National Veterinary Services to overcome domestic resistance.     

Practice management software for the equine practitioner.

Practice management software benefits the equine practitioner in many ways. Ready access to patient records, rapid entry and lookup of clinical findings, easy invoicing and monitoring of revenues, inventory management, rapid search and sorting of data, reminder and recall maintenance, and integrated word processing are just some of the software functions that assist the successful practitioner. Computer use in veterinary practice may have seemed to many to be a gimmick at one time. Now that computers have become a part of our everyday life, it is clear that they can be an essential component of the modem, successful, and profitable equine practice.     

Decision analysis model for paratuberculosis control in commercial dairy herds

A previous economic test-and-cull decision analysis model has been strengthened and updated with current epidemiologic information. Created using Excel and PrecisionTree software, the model incorporates costs and benefits of herd management changes, diagnostic testing, and different management actions based on test results to control paratuberculosis in commercial dairy herds. This novel "JD-Tree" model includes a herd management decision node (four options), a test/no test decision node (two options), a diagnostic test choice decision node (five options), test result chance nodes (four levels of possible results), and test action decision nodes (three options; cull, manage, no action). The model culminates in a chance node for true infection status. Outcomes are measured as a net cost-benefit value to the producer. The model demonstrates that improving herd management practices to control infection spread (hygiene) is often more cost-effective than testing; not all herds should test as part of a paratuberculosis control program. For many herds, low-cost tests are more useful than more sensitive, higher cost tests. The model also indicates that test-positive cows in early stages of infection may be retained in the herd to generate farm income, provided they are managed properly to limit infection transmission. JD-Tree is a useful instructional tool, helping veterinarians understand the complex interactions affecting the economics of paratuberculosis control and to define the accuracy and cost specifications of better diagnostic tests.     

The case for mandatory inclusion of ethics within the zoological sciences curriculum

Traditionally, undergraduate science curricula include little or no “ethics,” either as theory or practice. However, zoologists are currently enjoying considerable media exposure: some of it positive (as in conservation practice), but more often negative (pertaining to issues such as the use of animals for testing of drugs, and genetic engineering). More than ever before, zoologists are being asked to make value judgments, and many of these involve moral assessment; if we accept that zoologists (along with other scientists) are professionals, then we must accept that they are responsible for any decisions they make, and it then follows that they are accountable, which can have serious ramifications in cases of malpractice. Ethics involves the application of morality in a professional setting. In light of this, teaching ethics is mandatory in degree programs such as engineering and medicine. This paper contends that a key output of zoological education is the undergraduate who is cognizant of the ethical framework and constructs within which he/she must function. The paper concludes with comment on the nature and style of delivery of ethics education.     

Techniques of reporting disease outbreak investigations

Effective communication of results and recommendations among veterinarians and between veterinarians and clients is an essential but often neglected component of an outbreak investigation. Although results have been traditionally related verbally, written reports are essential to minimize possible misunderstandings and provide a reference base for future herd health visits or epidemiologic investigations. A uniform reporting scheme for disease investigations by field veterinarians does not exist, but such a system would be desirable to allow comparisons of disease rates and productivity data among herds. In this article, a report format and style is outlined to facilitate exchange of data among veterinarians and clients. Reports to other veterinarians should include the following elements: history, objectives, methodology, results, causes/hypotheses, financial impact, and recommendations. For a client, a report should emphasize causes, recommendations, and the cost of measures to control the condition. Report planning, writing, and editing are facilitated by use of word-processing software on a microcomputer. Style will vary considerably according to the writer's objectives and individual preference, but headings, subheadings, graphs, and tables can be used to increase the visual appeal and readability of a report. The level of technicality should be appropriate for the audience. Sentences should be well constructed and precise.     

Technical note: Calculation of standard errors of estimates of genetic parameters with the multiple-trait derivative-free restricted maximal likelihood programs

The multiple-trait derivative-free REML set of programs was written to handle partially missing data for multiple-trait analyses as well as single-trait models. Standard errors of genetic parameters were reported for univariate models and for multiple-trait analyses only when all traits were measured on animals with records. In addition to estimating (co)variance components for multiple-trait models with partially missing data, this paper shows how the multiple-trait derivative-free REML set of programs can also estimate SE by augmenting the data file when not all animals have all traits measured. Although the standard practice has been to eliminate records with partially missing data, that practice uses only a subset of the available data. In some situations, the elimination of partial records can result in elimination of all the records, such as one trait measured in one environment and a second trait measured in a different environment. An alternative approach requiring minor modifications of the original data and model was developed that provides estimates of the SE using an augmented data set that gives the same residual log likelihood as the original data for multiple-trait analyses when not all traits are measured. Because the same residual vector is used for the original data and the augmented data, the resulting REML estimators along with their sampling properties are identical for the original and augmented data, so that SE for estimates of genetic parameters can be calculated.     

Importance of diagnostic aspects in ostertagism

Diagnostic methods which reveal only the presence or absence of Ostertagia in grazing animals are of little importance since all will acquire some degree of infection when grazed in the temperate regions of the world. Ostertagia infections may be (1) light--no disease or performance losses occur; (2) moderate--disease may or may not be overtly visible but performance losses occur or (3) heavy--disease is overt with or without death loss. The differentiation of these levels of infection is a quantitative matter insofar as the number of parasites correlates with the degree of pathology and is much less certain than is the presence or absence of infection. Historically, the quantitative parasite egg count in feces (eggs per gram (e.p.g.)), combined with the usual subjective and objective information obtained in clinical examinations has been the procedure used to obtain a quantitative estimate of the level of infection. More recently, the use of plasma pepsinogen levels as an indication of gastric pathology has been adopted by some laboratories. Neither of these methods have met with the desired level of accuracy, but they do have considerable value when their limitations are recognized. In the present era of emphasis on epidemiologically based control programs we are faced with yet another aspect of diagnosis, namely that of a quantitative estimate of numbers of infective stages (L3) on herbage. Methods to assess the number of L3 on forage are not satisfactory for routine clinical use. This paper evaluates the primary objectives of diagnosis as applied to the herd and flock. It briefly evaluates current methodology insofar as the diagnosis of parasitic gastroenteritis is concerned. The use of e.p.g. counts in clinical practice is discussed. Examples applicable to herds of weaner and stocker cattle are presented.     

Practical implications of plant-derived antimicrobials in poultry diets for the control of Salmonella Enteritidis

Several plant-derived antimicrobials have been tested under laboratory or research farm conditions and have been shown to be effective in reducing the colonization and shedding of Salmonella Enteritidis from laying hens and broiler chickens when added to the feed. How well these particular compounds or essential oils work under commercial conditions is yet to be determined. Some of the practical implications of using these compounds in commercial poultry feed or diets are discussed in this paper. In general, an ample supply of many of these compounds exist, they are relatively easily mixed with other feed ingredients, and are effective at relatively small amounts. The cost of adding to the feed is still a variable and the total economic effect can only be estimated at this point.     

The usefulness and limitations of hand-held refractometers in veterinary laboratory medicine: an historical and technical review

Abstract: Medical hand-held refractometers have been used in veterinary practice since their development in the 1960s. They have become ubiquitous for the measurement of protein and urine solute concentrations because of their rapidity of analysis, ease of use, and relatively low cost. Refraction of light offers advantages for the determination of solute concentrations because the measurement requires no chemical alteration of the specimen. Numerous authors have reported that the results of protein estimation by refractometry for domestic mammals correlate well with those obtained by the biuret method, although others have reported both higher and lower refractometric results compared with biuret results. Major discrepancies between biuret and refractometric results have been reported for avian samples. Some of the variation in reported results may be due to differences in design by refractometer manufacturers. Another possible source may be variation in the biuret reagent mixture and assay conditions. Refractometers also can be used to calculate serum water concentration. A table that converts index of refraction to serum water concentration can be used to convert electrolyte concentration from mmol/L of serum to mmol/L of serum water, a more accurate indicator of effective electrolyte concentration. Refractometers are especially useful for determining urine specific gravity on veterinary samples because they require relatively small sample volumes. Specific gravity continues to be the most common unit for reporting total solids concentration. Some solutes, such as acetone, may cause false increases in specific gravity by refractometry, as they increase refraction but are less dense than water.     

The welfare significance of the castration of cattle: a review

Castration is an ancient husbandry procedure used to produce docile cattle for draught work, to reduce unwanted breeding, and to modify carcass quality. All the physical methods used to castrate cattle have side-effects and cause pain. The plasma cortisol response to castration using Burdizzo clamps and, by inference, the acute pain experienced, is less than that caused by surgical, rubber-ring or latex-band castration. The cortisol response may be influenced by the age of the animal castrated, but this has not been well defined. Local anaesthesia virtually eliminates the cortisol response, and thus the acute pain, caused by rubber-ring or latex-band castration, but needs to be combined with a systemic analgesic such as the non-steroidal anti-inflammatory drug ketoprofen to eliminate the cortisol response to Burdizzo or surgical castration. When used alone, ketoprofen sometimes reduces the cortisol response to Burdizzo or surgical castration but may need to be accompanied by local anaesthesia to eliminate the pain-induced behaviour seen during the castration process itself. Thus, pharmacological methods are available to virtually eliminate the acute pain experienced by calves during the 12 h following castration. The use of these methods is an additional cost for farmers and may be limited by the availability of drugs for farmers to use and the scarcity of veterinarians in farm animal practice.     

The welfare significance of the castration of cattle: A review

Castration is an ancient husbandry procedure used to produce docile cattle for draught work, to reduce unwanted breeding, and to modify carcass quality. All the physical methods used to castrate cattle have side-effects and cause pain. The plasma cortisol response to castration using Burdizzo clamps and, by inference, the acute pain experienced, is less than that caused by surgical, rubber-ring or latex-band castration. The cortisol response may be influenced by the age of the animal castrated, but this has not been well defined. Local anaesthesia virtually eliminates the cortisol response, and thus the acute pain, caused by rubber-ring or latex-band castration, but needs to be combined with a systemic analgesic such as the non-steroidal anti-inflammatory drug ketoprofen to eliminate the cortisol response to Burdizzo or surgical castration. When used alone, ketoprofen sometimes reduces the cortisol response to Burdizzo or surgical castration but may need to be accompanied by local anaesthesia to eliminate the pain-induced behaviour seen during the castration process itself. Thus, pharmacological methods are available to virtually eliminate the acute pain experienced by calves during the 12 h following castration. The use of these methods is an additional cost for farmers and may be limited by the availability of drugs for farmers to use and the scarcity of veterinarians in farm animal practice.     

Tremorgenic syndromes in livestock

Grasses that are essential components of livestock grazing programs sometimes are the source of tremorgenic toxicants to the animals consuming them. Morbidity can be high but mortality need not be if management closely observes the cattle daily and removes them at first sign of trouble. Specific treatment generally is not available nor needed. Survivors recover completely within a few days or weeks, except in chronic phalaris poisoning, where sheep and cattle may die after prolonged illness--or at least not make an economical recovery. Certain poisonous plants are responsible for tremorgenic signs in livestock and horses. White snakeroot and rayless goldenrod pose a public health risk to individuals who might drink milk from a goat or cow grazing toxic amounts of these weeds. Poisonous weeds and trees often are a local or regional problem, and often are seasonal. A veterinarian new to the area who has a food animal practice should seek out information relative to poisonous plants, nutritional deficiencies, and diseases endemic to the practice area. The ability of certain fungi to produce toxic metabolites in feed-stuffs creates the potential for tremorgenic or other types of toxicosis in most classes of livestock. Wet grain byproducts from ethanol production and other processes can provide the right culture media for fungi.     

Perceptions of fourth-year veterinary students about the human-animal bond in veterinary practice and in veterinary college curricula

OBJECTIVE: To assess veterinary students' perceptions regarding the importance of addressing the human-animal bond in veterinary practice and their perceptions about the adequacy of curricula on the human-animal bond as presented in US veterinary colleges. DESIGN: Survey. PROCEDURE: Data were collected via a brief questionnaire mailed during the summer of 1996. Questionnaires were returned by 552 senior veterinary students representing 21 of 27 veterinary colleges in the United States. RESULTS: Senior veterinary students believed that the human-animal bond should be a concern of practicing veterinarians, but most did not believe they were receiving adequate instruction about the human-animal bond in their veterinary colleges. Gender was significantly related to differences in perceptions; female students appeared to have more interest in addressing the human-animal bond than male students. Students in small animal programs viewed the human-animal bond differently than those in large animal programs. Finally, students attending schools with extensive human-animal bond or human relations curricula were more likely to believe they were receiving adequate instruction in this area than students in other schools. CONCLUSIONS AND CLINICAL IMPLICATIONS: Curricula addressing the human-animal bond need to be developed and implemented in veterinary colleges in the United States.     

Nutrition and the integument

Although nutritional deficiencies, imbalances and toxicities may be specific, they all tend to produce general, non-specific skin changes. Tests to determine nutrient levels in tissues or serum are expensive and rarely diagnostic. Careful evaluation of genetic factors and the dietary history may give clues to the diagnosis; and test feedings or trial medications may produce clinical response. Except for food hypersensitivities, which may be common in certain individuals, pets fed complete, balanced commercial diets rarely have skin disorders caused by nutritional factors.