The application of risk analysis in aquatic animal health management

Risk analysis has only been regularly used in the management of aquatic animal health in recent years. The Agreement on the Application of Sanitary and Phytosanitary measures (SPS) stimulated the application of risk analysis to investigate disease risks associated with international trade (import risk analysis-IRA). A majority (9 of 17) of the risk analyses reviewed were IRA. The other major focus has been the parasite of Atlantic salmon--Gyrodactylus salaris. Six studies investigated the spread of this parasite, between countries, rivers and from farmed to wild stocks, and clearly demonstrated that risk analysis can support aquatic animal health policy development, from international trade and biosecurity to disease interaction between wild and farmed stocks. Other applications of risk analysis included the spread of vertically transmitted pathogens and disease emergence in aquaculture. The Covello-Merkhofer, risk analysis model was most commonly used and appears to be a flexible tool not only for IRA but also the investigation of disease spread in other contexts. The limitations of the identified risk assessments were discussed. A majority were qualitative, partly due to the lack of data for quantitative analysis, and this, it can be argued, constrained their usefulness for trade purposes (i.e. setting appropriate sanitary measures); in other instances, a qualitative result was found to be adequate for decision making. A lack of information about the disease hazards of the large number of fish species traded is likely to constrain quantitative analysis for a number of years. The consequence assessment element of a risk analysis was most likely to be omitted, or limited in scope and depth, rarely extending beyond examining the evidence of susceptibility of farmed and wild species to the identified hazard. The reasons for this are discussed and recommendations made to develop guidelines for a consistent, systematic and multi-disciplinary approach to consequence assessment. Risk analysis has improved decision making in aquatic animal health management by providing a transparent method for using the available scientific information. The lack of data is the main constraint to the application of risk analysis in aquatic animal health. The identification of critical parameters is an important output from risk analysis models which should be used to prioritise research.     

锌对动物体健康影响的研究进展

微量元素锌(Zn)是动物必需的矿物质元素,其作用及临床应用是当前微量元素营养研究中较为突出的一种。大量研究证明,锌在动物生长发育过程中具有极其重要的生理功能和营养作用。1影响锌吸收与代谢的因素———因子间的互作食物中的组氨酸、谷氨酸利于锌的吸收;多量谷物、牛奶显著抑制锌的吸收;周期表上与锌邻近的钙、汞、镉、铅、铁、铜等元素,可在分子水平上与锌相竞争,故如果上述元素过量可抑制锌的吸收;反之,锌过量也可抑制硒的吸收而产生类似维生素E缺乏症。在饲粮中使用高铜、高锌,必须同时使用高铁。过多的钙可与植酸锌形成锌—植酸—…     

Structure discovery in Bayesian networks: an analytical tool for analysing complex animal health data

Analysing animal health data can be a complex task as the health status of individuals or groups of animals, might depend on many inter-related variables. The objective is to differentiate variables that are directly associated with health status and therefore promising targets for intervention, from variables that are indirectly associated with health status and can therefore at best only affect this indirectly through association with other variables. Bayesian network (BN) modelling is a machine learning technique for empirically identifying associations in complex and high dimensional data, so-called "structure discovery". An introduction to structure discovery using BN modelling is presented, comprising the key assumptions required by the methodology, along with a discussion of advantages and limitations. To demonstrate the various steps required to apply BN structure discovery to animal health data, illustrative analyses of data collected during a previously published study concerned with exposure to bovine viral diarrhoea virus in beef cow-calf herds in Scotland are presented.     

Data warehouse for assessing animal health, welfare, risk management and -communication

The objective of this paper is to give an overview of existing databases in Denmark and describe some of the most important of these in relation to establishment of the Danish Veterinary and Food Administrations' veterinary data warehouse. The purpose of the data warehouse and possible use of the data are described. Finally, sharing of data and validity of data is discussed. There are databases in other countries describing animal husbandry and veterinary antimicrobial consumption, but Denmark will be the first country relating all data concerning animal husbandry, -health and -welfare in Danish production animals to each other in a data warehouse. Moreover, creating access to these data for researchers and authorities will hopefully result in easier and more substantial risk based control, risk management and risk communication by the authorities and access to data for researchers for epidemiological studies in animal health and welfare.     

Developing a working partnership for animal health and welfare

The Animal Health and Welfare Board for England was established last year to act as the main source of advice to Defra ministers on animal health and welfare policy. Its recommendations will affect the health and welfare of all kept animals, including farm animals, horses and pets. Board member Mark Tufnell, whose responsibilities include liaising with the veterinary profession, describes its objectives and way of working.     

Fluoroquinolones in animal health

The fluoroquinolones are a series of synthetic antibacterial agents that are undergoing extensive investigation for both human and veterinary use in the treatment of a variety of bacterial infections. These agents work through the inhibition of DNA gyrase, interfering with the supercoiling of bacterial chromosomal material. As a result, these agents are rapidly bactericidal primarily against gram-negative bacteria, mycoplasma, and some grampositive bacteria, with most having little to no activity against group D streptococci and obligate anaerobic bacteria. Resistance develops slowly and is almost always chromosomal and not plasmid-mediated. However, development of resistance to the fluoroquinolones and transfer of that resistance among animal and human pathogens have become a hotly debated issue among microbiologists. The fluoroquinolones are a current antimicrobial class whose use in veterinary medicine is being scrutinized. From a pharmacokinetic perspective, these agents are variably but well absorbed from the gastrointestinal tract and almost completely absorbed from parenteral injection sites, and they are well distributed to various tissues in the body. The fluoroquinolones are metabolized and renally excreted, with many of them having approximately equal excretion by the hepatic and the renal excretory systems. The primary toxicity observed at therapeutic doses involves the gastrointestinal system and phototoxicity, although at higher doses central nervous system toxicity and ocular cataracts are observed. Administration to immature animals may result in erosive arthropathies at weight-bearing joints, and administration of high doses to pregnant animals results in maternotoxicity and occasionally embryonic death. The fluoroquinolones are approved for indications such as urinary tract infections and soft tissue infections in dogs and cats and colibacillosis in poultry. Approval for bovine respiratory disease in the United States is being sought. Other indications for which the fluoroquinolones have been used in animal health include deep-seated infections, prostatitis, and other bacterial infections resistant to standard antimicrobial therapy.     

Need for a new kind of partnership on animal health

The report from the England Advisory Group on Responsibility and Cost Sharing recommends a new approach built around the idea of an England Partnership Board. Rosemary Radcliffe, the group's chair, gives her perspective.     

Communication in production animal medicine: modelling a complex interaction with the example of dairy herd health medicine

Background

The importance of communication skills in veterinary medicine is increasingly recognised. Appropriate communication skills towards the client are of utmost importance in both companion animal practice and production animal field and consultancy work. The need for building a relationship with the client, alongside developing a structure for the consultation is widely recognised and applies to both types of veterinary practice.

Results

Veterinary advisory practice in production animal medicine is, however, characterised by a more complex communication on different levels. While the person-orientated communication is a permanent process between veterinarian and client with a rather personal perspective and defines the roles of interaction, the problem-orientated communication deals with emerging difficulties; the objective is to solve an acute health problem. The solution - orientated communication is a form of communication in which both veterinarian and client address longstanding situations or problems with the objective to improve herd health and subsequently productivity performance. All three forms of communication overlap.

Conclusions

Based on this model, it appears useful for a veterinary practice to offer both a curative and an advisory service, but to keep these two separated when deemed appropriate. In veterinary education, the strategies and techniques necessary for solution orientated communication should be included in the teaching of communication skills.     

Molecular cross-sectional survey of gastric habronemosis in horses

Gastric habronemosis of horses caused by Habronema microstoma and Habronema muscae (Nematoda, Spirurida) is characterized by catarrhal gastritis, diarrhoea, progressive weight loss and ulcers. Despite its importance in the equine industry and in clinical practice, knowledge of the epidemiology of this infection is still incomplete as diagnosis in live animals is challenging. A two-step semi-nested PCR assay using ribosomal DNA (rDNA) markers has recently been used for the molecular diagnosis in vivo of gastric habronemosis based on the detection of H. microstoma and/or H. muscae DNA in equine faeces. To evaluate the field efficacy of this assay, a molecular epidemiological survey was carried out on equid gastric habronemosis in central Italy. One hundred and fifty-three individual faecal samples were collected from live native horses and subjected to both coprological examination and the two-step semi-nested PCR. When flotation procedures were performed no horse tested positive for Habronema spp. larvated eggs while 96 animals (61.2%) were positive for other endoparasites (i.e. strongyles, oxyurids, ascarids). Two-step semi-nested PCR detected 86 samples (53.6%) that were positive for H. microstoma and/or H. muscae DNA. H. microstoma prevalences showed statistically significant differences; the highest prevalence was observed in horses infected by other gastrointestinal parasites and concomitantly by H. muscae. No statistical differences were found between the prevalence of Habronema spp. infection and sex, age, breeding management, and antiparasitic treatments. This field survey provided further information on habronemosis and its epidemiology.     

Evaluation of a monitoring system for assessing animal health in dairy cattle

A monitoring system to assess animal health in dairy farms was developed and applied on 44 farms in an epidemiological study. The objective of the study was to evaluate the applicability of the system for long term monitoring of health data. For this purpose, the quality of the collected data and the acceptance of the system by farmers and veterinarians were investigated. Farmers recorded all health events using a form. Collected data was entered into a central database on a monthly basis. The recording of health data was easy to do and did not take a lot of time. Most of the farmers (89%) used less than 20 minutes per week for the recording. This time need was independent of the herd size. 66% of the farmers found it useful to record health data, especially for improving their overview on health of each single cow. Treatments were reported in 81% of the cases, inseminations and calving in 80% of the cases. All events were reported correctly and precise.     

Promoting transboundary animal disease risk management via a multiple health and husbandry intervention strategies in upland Lao PDR

Surveys of smallholder farmer knowledge, attitude, practice (KAP) and income were conducted in 2011 and 2012 in five northern provinces of Lao People’s Democratic Republic (Lao PDR; n?=?200 farmers). Participating villages were classified as either from a livelihood development project (LV; n?=?80 farmers) or a livestock research project that contained both ‘high-intervention’ (HI; n?=?60 farmers) or ‘low-intervention’ (LI; n?=?60 farmers) villages. Farmer training plus a suite of health and productivity interventions were implemented in HI sites; only vaccination was implemented in LI sites, whilst various interventions and limited vaccination were introduced to LV sites. Farmer interviews were conducted with survey questions on socioeconomic variables and KAP of large ruminant health and disease risk management, enabling determination of quantitative and dichotomous qualitative traits and comparison of results from HI, LI and LV villages. The average farmer income from sales of large ruminants in HI was USD 621, in LI was USD 547 and in LV was USD 225 (p?<?0.001). The predicted mean of total knowledge scores (/42) in the 2012 survey in HI was 28, in LI was 22 and in LV was 17 (p?<?0.001). We conclude that improved KAP of large ruminant health and production can be achieved by intensive training, although with some farmers yet to apply their knowledge on husbandry and biosecurity practices, continued learning support and closed linkage of research and development projects to improve extension capacity is recommended. This multiple participatory approach promoting biosecurity in addition to vaccination may provide a more sustainable pathway for the advancement of Lao PDR on the Progressive Control Pathway for foot and mouth disease control.     

Threshold-linear versus linear-linear analysis of birth weight and calving ease using an animal model: I. Variance component estimation.

Birth weight and calving difficulty were analyzed with Bayesian methodology using univariate linear models, a bivariate linear model, a threshold model for calving difficulty, and a joint threshold-linear model using a probit approach. Field data included 26,006 records of Gelbvieh cattle. Simulated populations were generated using parameters estimated from the field data. The Gibbs sampler was used to obtain estimates of the marginal posterior mean and standard deviation of the (co)variance components, heritabilities, and correlations. In the univariate analyses, the posterior mean of direct heritability for calving difficulty was .23 with the threshold model and .18 with the linear model. Maternal heritabilities were .10 and .08, respectively. In the bivariate analysis, posterior means of direct heritability for calving difficulty were .21 and .18 for the bivariate linear-threshold and linear-linear model, respectively. Maternal heritabilities were .09 and .06, respectively. Direct heritability for birth weight was .25 for the univariate model and .26 for bivariate models. Maternal heritability was .05 for the linear-threshold model and the univariate model and .06 for the bivariate linear model. Genetic correlation between direct genetic effects in both traits was .81 for the linear-threshold model and .79 for the bivariate linear. Residual correlation was .35 for the bivariate linear model and .50 for the bivariate linear-threshold. A simulation study confirmed that the posterior mean of the marginal distribution was suitable as a point estimate for univariate threshold and bivariate linear-threshold models.