1
|
Disturbance Ecology Meets Bovine Tuberculosis (bTB) Epidemiology: A Before-and-After Study on the Association between Forest Clearfelling and bTB Herd Risk in Cattle Herds. Pathogens 2022; 11:pathogens11070807. [PMID: 35890051 PMCID: PMC9321662 DOI: 10.3390/pathogens11070807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 02/01/2023] Open
Abstract
Disturbance ecology refers to the study of discrete processes that disrupt the structure or dynamics of an ecosystem. Such processes can, therefore, affect wildlife species ecology, including those that are important pathogen hosts. We report on an observational before-and-after study on the association between forest clearfelling and bovine tuberculosis (bTB) herd risk in cattle herds, an episystem where badgers (Meles meles) are the primary wildlife spillover host. The study design compared herd bTB breakdown risk for a period of 1 year prior to and after exposure to clearfelling across Ireland at sites cut in 2015–2017. The percent of herds positive rose from 3.47% prior to clearfelling to 4.08% after exposure. After controlling for confounders (e.g., herd size, herd type), we found that cattle herds significantly increased their odds of experiencing a bTB breakdown by 1.2-times (95%CIs: 1.07–1.36) up to 1 year after a clearfell risk period. Disturbance ecology of wildlife reservoirs is an understudied area with regards to shared endemic pathogens. Epidemiological observational studies are the first step in building an evidence base to assess the impact of such disturbance events; however, such studies are limited in inferring the mechanism for any changes in risk observed. The current cohort study suggested an association between clearfelling and bTB risk, which we speculate could relate to wildlife disturbance affecting pathogen spillback to cattle, though the study design precludes causal inference. Further studies are required. However, ultimately, integration of epidemiology with wildlife ecology will be important for understanding the underlying mechanisms involved, and to derive suitable effective management proposals, if required.
Collapse
|
2
|
Downs SH, Prosser A, Ashton A, Ashfield S, Brunton LA, Brouwer A, Upton P, Robertson A, Donnelly CA, Parry JE. Assessing effects from four years of industry-led badger culling in England on the incidence of bovine tuberculosis in cattle, 2013-2017. Sci Rep 2019; 9:14666. [PMID: 31604960 PMCID: PMC6789095 DOI: 10.1038/s41598-019-49957-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 07/30/2019] [Indexed: 11/09/2022] Open
Abstract
The objective was to measure the association between badger culling and bovine tuberculosis (TB) incidents in cattle herds in three areas of England between 2013-2017 (Gloucestershire and Somerset) and 2015-2017 (Dorset). Farming industry-selected licensed culling areas were matched to comparison areas. A TB incident was detection of new Mycobacterium bovis infection (post-mortem confirmed) in at least one animal in a herd. Intervention and comparison area incidence rates were compared in central zones where culling was conducted and surrounding buffer zones, through multivariable Poisson regression analyses. Central zone incidence rates in Gloucestershire (Incidence rate ratio (IRR) 0.34 (95% CI 0.29 to 0.39, p < 0.001) and Somerset (IRR 0.63 (95% CI 0.58 to 0.69, p < 0.001) were lower and no different in Dorset (IRR 1.10, 95% CI 0.96 to 1.27, p = 0.168) than comparison central zone rates. The buffer zone incidence rate was lower for Gloucestershire (IRR 0.64, 95% CI 0.58 to 0.70, p < 0.001), no different for Somerset (IRR 0.97, 95% CI 0.80 to 1.16, p = 0.767) and lower for Dorset (IRR 0.45, 95% CI 0.37 to 0.54, p < 0.001) than comparison buffer zone rates. Industry-led culling was associated with reductions in cattle TB incidence rates after four years but there were variations in effects between areas.
Collapse
Affiliation(s)
- Sara H Downs
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey, KT15 3NB, UK.
| | - Alison Prosser
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey, KT15 3NB, UK
| | - Adam Ashton
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey, KT15 3NB, UK
| | - Stuart Ashfield
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey, KT15 3NB, UK
| | - Lucy A Brunton
- Veterinary Epidemiology, Economics and Public Health Group, The Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, UK
| | - Adam Brouwer
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey, KT15 3NB, UK
| | - Paul Upton
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey, KT15 3NB, UK
| | - Andrew Robertson
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
- National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Nympsfield, Gloucestershire, GL10 3UJ, UK
| | - Christl A Donnelly
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, St Mary's campus, Norfolk Place, London, W2 1PG, UK
- Department of Statistics, University of Oxford, 24-29 St Giles', Oxford, OX1 3LB, UK
| | - Jessica E Parry
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey, KT15 3NB, UK
| |
Collapse
|
3
|
Performativity and a microbe: Exploring Mycobacterium bovis and the political ecologies of bovine tuberculosis. BIOSOCIETIES 2018; 14:179-204. [PMID: 32226469 PMCID: PMC7100403 DOI: 10.1057/s41292-018-0124-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mycobacterium bovis, the bacterium responsible for causing bovine tuberculosis (bTB) in cattle, displays what I call ‘microbial performativity’. Like many other lively disease-causing microorganisms, it has an agency which is difficult to contain, and there is a need for fresh thinking on the challenges of dealing with this slippery and indeterminate microbe. As a practising veterinary scientist who side-stepped mid-career into a parallel training in the social sciences to view bTB from an alternative perspective, I create an interdisciplinary coming-together where veterinary science converges with a political ecology of (animal) health influenced by science and technology studies (STS) and social science and humanities scholarship on performativity. This suitably hybridized nexus creates a place to consider the ecologies of a pathogen which could be considered as life out of control. I consider what this means for efforts to eradicate this disease through combining understandings from the published scientific literature with qualitative interview-based fieldwork with farmers, veterinarians and others involved in the statutory bTB eradication programme in a high incidence region of the UK. This study demonstrates the value of life scientists turning to the social sciences to re-view their familiar professional habitus—challenging assumptions, and offering alternative perspectives on complex problems.
Collapse
|
4
|
Abstract
Simon More and Guy McGrath raise issues relating to the Randomised Badger Culling Trial, that they feel warrant further discussion and study.
Collapse
Affiliation(s)
- Simon J More
- Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Guy McGrath
- Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| |
Collapse
|
5
|
More SJ, Good M. Understanding and managing bTB risk: perspectives from Ireland. Vet Microbiol 2015; 176:209-18. [PMID: 25724333 DOI: 10.1016/j.vetmic.2015.01.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 01/27/2015] [Accepted: 01/31/2015] [Indexed: 01/01/2023]
Abstract
There is substantial variation in herd risk for bovine tuberculosis (bTB) in Ireland, with most herds playing little to no role in the ongoing endemic. In infected areas, bTB persistence (affecting one or a group of herds) is a key feature of the infection. In this paper, we present our current understanding and management of bTB risk in Ireland, based on a detailed review of research and policy. There is close interaction between science and policy in Ireland, seeking both to understand and effectively manage bTB risk. Detailed research on bTB persistence is presented, including current understanding of the relative importance of different infection sources, which can include residual infection in cattle and/or re-infection, either from local sources or following cattle introduction. In recent years, there have been three primary drivers for policy change, including scientific advances, ongoing improvements to programme supports, and ongoing programme review. In this review, three key future programme challenges are identified. Although good progress is being made, eradication has not yet been achieved. Firstly, a key question concerns the additional effort that will be required, to move towards final eradication. Secondly, a percentage of non-infected animals are falsely positive to current testing methods. This is an ongoing challenge, given the imperfect specificity of test methods but will become more so, as the positive predictive value falls with reducing bTB prevalence. Finally, there is a need to re-engage with the farming community, so that they play a much greater role in programme ownership.
Collapse
Affiliation(s)
- Simon J More
- UCD Centre for Veterinary Epidemiology and Risk Analysis, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Margaret Good
- Department of Agriculture, Food and the Marine, Kildare St, Dublin 2, Ireland
| |
Collapse
|
6
|
Ní Bhuachalla D, Corner LA, More SJ, Gormley E. The role of badgers in the epidemiology of Mycobacterium bovis infection (tuberculosis) in cattle in the United Kingdom and the Republic of Ireland: current perspectives on control strategies. VETERINARY MEDICINE-RESEARCH AND REPORTS 2014; 6:27-38. [PMID: 30101094 PMCID: PMC6067767 DOI: 10.2147/vmrr.s53643] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Bovine tuberculosis (TB), caused by infection with Mycobacterium bovis, is a persistent problem in cattle herds in Ireland and the United Kingdom, resulting in hardship for affected farmers and substantial ongoing national exchequer expenditure. There is irrefutable scientific evidence that badgers are a reservoir of M. bovis infection and are implicated in the transmission of infection to cattle. A range of options for the control of TB in badgers is currently available or under development including culling of badgers, vaccination of badgers and cattle, and improved biosecurity to limit contact between the two species. It is unlikely that the eradication of TB from cattle will be achieved without the reservoir of M. bovis infection in badgers being controlled. The chances of success will, however, improve with greater knowledge of the disease in both species and an understanding of the epidemiological drivers of the transmission of infection between badgers and cattle.
Collapse
Affiliation(s)
| | - Leigh Al Corner
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland,
| | - Simon J More
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland, .,Centre for Veterinary Epidemiology and Risk Analysis, University College Dublin, Dublin, Ireland
| | - Eamonn Gormley
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland,
| |
Collapse
|
7
|
Karolemeas K, Donnelly CA, Conlan AJK, Mitchell AP, Clifton-Hadley RS, Upton P, Wood JLN, McKinley TJ. The effect of badger culling on breakdown prolongation and recurrence of bovine tuberculosis in cattle herds in Great Britain. PLoS One 2012; 7:e51342. [PMID: 23236478 PMCID: PMC3517421 DOI: 10.1371/journal.pone.0051342] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 11/01/2012] [Indexed: 11/19/2022] Open
Abstract
Bovine tuberculosis is endemic in cattle herds in Great Britain, with a substantial economic impact. A reservoir of Mycobacterium bovis within the Eurasian badger (Meles meles) population is thought to have hindered disease control. Cattle herd incidents, termed breakdowns, that are either ‘prolonged’ (lasting ≥240 days) or ‘recurrent’ (with another breakdown within a specified time period) may be important foci for onward spread of infection. They drain veterinary resources and can be demoralising for farmers. Randomised Badger Culling Trial (RBCT) data were re-analysed to examine the effects of two culling strategies on breakdown prolongation and recurrence, during and after culling, using a Bayesian hierarchical model. Separate effect estimates were obtained for the ‘core’ trial areas (where culling occurred) and the ‘buffer’ zones (up to 2 km outside of the core areas). For breakdowns that started during the culling period, ‘reactive’ (localised) culling was associated with marginally increased odds of prolongation, with an odds ratio (OR) of 1.7 (95% credible interval [CI] 1.1–2.4) within the core areas. This effect was not present after the culling ceased. There was no notable effect of ‘proactive’ culling on prolongation. In contrast, reactive culling had no effect on breakdown recurrence, though there was evidence of a reduced risk of recurrence in proactive core areas during the culling period (ORs and 95% CIs: 0.82 (0.64–1.0) and 0.69 (0.54–0.86) for 24- and 36-month recurrence respectively). Again these effects were not present after the culling ceased. There seemed to be no effect of culling on breakdown prolongation or recurrence in the buffer zones. These results suggest that the RBCT badger culling strategies are unlikely to reduce either the prolongation or recurrence of breakdowns in the long term, and that reactive strategies (such as employed during the RBCT) are, if anything, likely to impact detrimentally on breakdown persistence.
Collapse
Affiliation(s)
- Katerina Karolemeas
- Disease Dynamics Unit, Department of Veterinary Medicine. University of Cambridge, Cambridge, United Kingdom
| | - Christl A. Donnelly
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College, London, United Kingdom
| | - Andrew J. K. Conlan
- Disease Dynamics Unit, Department of Veterinary Medicine. University of Cambridge, Cambridge, United Kingdom
| | - Andrew P. Mitchell
- Animal Health and Veterinary Laboratories Agency, Weybridge, Surrey, United Kingdom
| | | | - Paul Upton
- Animal Health and Veterinary Laboratories Agency, Weybridge, Surrey, United Kingdom
| | - James L. N. Wood
- Disease Dynamics Unit, Department of Veterinary Medicine. University of Cambridge, Cambridge, United Kingdom
| | - Trevelyan J. McKinley
- Disease Dynamics Unit, Department of Veterinary Medicine. University of Cambridge, Cambridge, United Kingdom
- * E-mail:
| |
Collapse
|
8
|
Mycobacterium bovis: A Model Pathogen at the Interface of Livestock, Wildlife, and Humans. Vet Med Int 2012; 2012:236205. [PMID: 22737588 PMCID: PMC3377356 DOI: 10.1155/2012/236205] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 04/11/2012] [Indexed: 11/18/2022] Open
Abstract
Complex and dynamic interactions involving domestic animals, wildlife, and humans create environments favorable to the emergence of new diseases, or reemergence of diseases in new host species. Today, reservoirs of Mycobacterium bovis, the causative agent of tuberculosis in animals, and sometimes humans, exist in a range of countries and wild animal populations. Free-ranging populations of white-tailed deer in the US, brushtail possum in New Zealand, badger in the Republic of Ireland and the United Kingdom, and wild boar in Spain exemplify established reservoirs of M. bovis. Establishment of these reservoirs is the result of factors such as spillover from livestock, translocation of wildlife, supplemental feeding of wildlife, and wildlife population densities beyond normal habitat carrying capacities. As many countries attempt to eradicate M. bovis from livestock, efforts are impeded by spillback from wildlife reservoirs. It will not be possible to eradicate this important zoonosis from livestock unless transmission between wildlife and domestic animals is halted. Such an endeavor will require a collaborative effort between agricultural, wildlife, environmental, and political interests.
Collapse
|
9
|
O'Connor CM, Haydon DT, Kao RR. An ecological and comparative perspective on the control of bovine tuberculosis in Great Britain and the Republic of Ireland. Prev Vet Med 2011; 104:185-97. [PMID: 22192362 DOI: 10.1016/j.prevetmed.2011.11.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 01/09/2023]
Abstract
Disease ecology involves a systematic approach to understanding the interactions and evolution of host-pathogen systems at the population level, and is essential for developing a comprehensive understanding of the reasons for disease persistence and the most likely means of control. This systems or ecological approach is being increasingly recognised as a progressive method in disease control and is exploited in diverse fields ranging from obesity management in humans to the prevention of infectious disease in animal populations. In this review we discuss bovine tuberculosis (bTB) in Great Britain (GB) within a disease ecology context, and suggest how a comparative ecological perspective helps to reconcile apparent conflicts with the evidence on the effectiveness of badger culling to assist in the control of bTB in GB and the Republic of Ireland (ROI). Our examination shows that failure of past measures to control bTB and the disparity in outcomes of badger culling experiments are the result of a complex relationship amongst the agent, host and environment, i.e. the episystem, of bTB. Here, we stress the role of distinctive bTB episystems and badger culling trial design in the ambiguity and resulting controversy associated with badger culling in GB and ROI. We argue this episystem perspective on bTB control measures in cattle and badger populations provides a useful and informative perspective on the design and implementation of future bTB management in GB, particularly at a time when both scientific and lay communities are concerned about the ongoing epidemic, the cost of current control measures and the execution of future control procedures.
Collapse
Affiliation(s)
- Catherine M O'Connor
- Boyd Orr Centre for Population and Ecosystem Health, Institute for Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Jarrett Building, 464 Bearsden Rd, Glasgow G61 1QH, United Kingdom.
| | | | | |
Collapse
|
10
|
Vial F, Donnelly CA. Localized reactive badger culling increases risk of bovine tuberculosis in nearby cattle herds. Biol Lett 2011; 8:50-3. [PMID: 21752812 DOI: 10.1098/rsbl.2011.0554] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human and livestock diseases can be difficult to control where infection persists in wildlife populations. Control of bovine tuberculosis (bTB) in British cattle is complicated by the maintenance of Mycobacterium bovis (the causative agent of bTB) in badgers, acting as reservoirs of infection. Although over 20 000 badgers were culled to control bTB between 1975 and 1997, the incidence of bTB in cattle has substantially increased in parts of Great Britain in recent decades. Our case-control study, involving 1208 cattle herds, provides further evidence of the detrimental effect of localized reactive badger culling in response to the disclosure of a confirmed bTB herd breakdown in cattle. The presence of any reactive badger culling activity and increased numbers of badgers culled in the vicinity of a herd were associated with significantly increased bTB risk, even after adjusting for other important local risk factors. Such findings may partly explain why some earlier localized approaches to bTB control were ineffective.
Collapse
Affiliation(s)
- Flavie Vial
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | | |
Collapse
|
11
|
Wilson GJ, Carter SP, Delahay RJ. Advances and prospects for management of TB transmission between badgers and cattle. Vet Microbiol 2011; 151:43-50. [DOI: 10.1016/j.vetmic.2011.02.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
12
|
|
13
|
Torgerson PR, Torgerson DJ. Public health and bovine tuberculosis: what's all the fuss about? Trends Microbiol 2010; 18:67-72. [DOI: 10.1016/j.tim.2009.11.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 10/21/2009] [Accepted: 11/05/2009] [Indexed: 10/20/2022]
|
14
|
More SJ. What is needed to eradicate bovine tuberculosis successfully: an Irish perspective. Vet J 2009; 180:275-8. [DOI: 10.1016/j.tvjl.2009.01.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 01/29/2009] [Accepted: 01/31/2009] [Indexed: 11/29/2022]
|
15
|
The effects of annual widespread badger culls on cattle tuberculosis following the cessation of culling. Int J Infect Dis 2008; 12:457-65. [DOI: 10.1016/j.ijid.2008.04.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 04/03/2008] [Accepted: 04/09/2008] [Indexed: 11/24/2022] Open
|
16
|
White PCL, Böhm M, Marion G, Hutchings MR. Control of bovine tuberculosis in British livestock: there is no 'silver bullet'. Trends Microbiol 2008; 16:420-7. [PMID: 18706814 DOI: 10.1016/j.tim.2008.06.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 06/05/2008] [Accepted: 06/18/2008] [Indexed: 11/26/2022]
Abstract
Bovine tuberculosis (bTB; Mycobacterium bovis) is a bacterial infection of cattle that also affects certain wildlife species. Culling badgers (Meles meles), the principal wildlife host, results in perturbation of the badger population and an increased level of disease in cattle. Therefore, the priority for future management must be to minimize the risk of disease transmission by finding new ways to reduce the contact rate among the host community. At the farm level, targeting those individuals that represent an elevated risk of transmission might prove to be effective. At the landscape level, risk mapping can provide the basis for targeted surveillance of the host community. Here, we review the current evidence for bTB persistence in Britain and make recommendations for future management and research.
Collapse
Affiliation(s)
- Piran C L White
- Environment Department, University of York, Heslington, York, YO10 5DD, UK.
| | | | | | | |
Collapse
|
17
|
Bourne FJ, Donnelly CA, Cox DR, Gettinby G, McInerney JP, Morrison WI, Woodroffe R. Re: TB policy and the ISG's findings. Vet Rec 2007; 161:633-5. [PMID: 17982145 DOI: 10.1136/vr.161.18.633-b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
18
|
Gallagher J, Sainsbury RMQ, Muirhead RH, Smith J, Ashton WLG, Davies JI, Cohen J. TB policy and the ISG's findings. Vet Rec 2007; 161:495-6. [DOI: 10.1136/vr.161.14.495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|