A molecular epidemiological approach to combating footrot an endemic disease of sheep
Lead Research Organisation:
University of Warwick
Department Name: Biological Sciences
Abstract
Lameness in sheep is painful. In Great Britain over 95% of flocks have approximately 10% of sheep lame at any one time and 80% of this lameness is caused by footrot. There are approximately 1.6 million lame sheep in GB at any time. Footrot is estimated to cost the UK industry £31 million per year and is a huge worry to sheep farmers who do not feel that advice to manage this disease is successful. Footrot is an infectious disease caused by invasion of the skin between the claws of the foot with a bacterium called Dichelobacter nodosus. Surprisingly little is known about how this bacterium causes disease and how it survives (on the sheep or in the environment) when it is not causing disease. Over the past 7 years we have studied practical aspects of control of footrot. The key results were that farmers who treated lame sheep promptly with injectable antibiotics had low levels of lame sheep in their flocks (4% versus 12%) and also that trimming feet (traditionally used to control footrot) was associated with high levels of disease. These facts suggest that the bacteria may be much more widely spread in the environment than previously suspected from research in Australia. We know that the environment plays a role in disease occurrence. D. nodosus survives better in warm wet weather. We also know that there are several strains of the bacterium that can affect the severity of disease. However, we do not know which aspects of the environment or the bacterial strains are important in determining disease severity and persistence on farms. The bacteria may survive in pasture, in the gut or on feet of the non-diseased sheep. During our work we collected a large store of D. nodosus from swabs of sheep with and without disease and also stored bacterial DNA from the feet of sheep. We also have two years data from approximately 800 ewes and their lambs. Every occurrence of lameness has been recorded and investigated and samples taken to investigate whether D. nodosus was present. From these data we can form mathematical models that describe when a sheep became lame, how long she was lame for and factors that influenced the speed with which she recovered and, unfortunately for some, became lame again. The plan of work we propose is to analyse the data above as described and to add in new findings about D. nodosus from laboratory studies into the ability of strains to cause disease and their survival in the environment. Using results from these studies and our models we will be able to work out which strains of D. nodosus cause most disease and how important the environment and host are in their survival. The ultimate aim is to provide better advice on control of footrot and so lower the occurrence of this disease.
Technical Summary
Footrot, caused by the bacterium Dichelobacter nodosus, is an endemic disease of enormous economic and welfare importance that has undermined the sustainability of the sheep industry for centuries. Little progress has been made in the understanding of disease persistence and a multidisciplinary approach using state-of-the-art molecular techniques and mathematical models is very timely. Farmers identify footrot as their greatest cause of concern in sheep health and recent advances in molecular tools and epidemiological analyses, particularly approaches to strain variation and predictive modelling, make this a feasible project. Current understanding of the relationship between D. nodosus and FR cannot distinguish between 4 hypotheses. These differ in terms of whether D. nodosus survives in the foot or the environment, whether such survival is short or long-term, and hence how transmission occurs. The involvement of other saprophytic, commensal and pathogenic bacteria and the genetic and virulence variation within D. nodosus are other variables to be considered. The over-arching aim is to study the population dynamics and population genetics of D. nodosus with a view to enhancing FR control strategies. We propose a multidisciplinary research programme that uses existing datasets (epidemiological and biological) and exploits recent scientific developments in epidemiology and molecular biology to further our understanding of FR in sheep. Our aim is to use these original data and new molecular biological categorisations and generate mathematical and statistical models to test the hypotheses and eliminate all but one. We will conclude the programme of work by using the remaining hypothesis to design a cohort study in year 4 of the proposal. Healthy and clinically affected sheep will be sampled, collecting data that will be determined from the first three years work. Biological and epidemiological analysis will be used to further our understanding from years 1-3.
Publications
Muzafar M
(2015)
The role of the environment in transmission of Dichelobacter nodosus between ewes and their lambs.
in Veterinary microbiology
Muzafar M
(2016)
Survival of the ovine footrot pathogen Dichelobacter nodosus in different soils
in Anaerobe
O'Kane H
(2017)
Associations between sheep farmer attitudes, beliefs, emotions and personality, and their barriers to uptake of best practice: The example of footrot.
in Preventive veterinary medicine
Prosser NS
(2020)
Serogroups of Dichelobacter nodosus, the cause of footrot in sheep, are randomly distributed across England.
in Scientific reports
Russell CL
(2014)
Multiple locus VNTR analysis highlights that geographical clustering and distribution of Dichelobacter nodosus, the causal agent of footrot in sheep, correlates with inter-country movements.
in Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases
Russell VN
(2013)
The interaction of host genetics and disease processes in chronic livestock disease: a simulation model of ovine footrot.
in Preventive veterinary medicine
Smith EM
(2014)
Dynamics and impact of footrot and climate on hoof horn length in 50 ewes from one farm over a period of 10 months.
in Veterinary journal (London, England : 1997)
Winter JR
(2015)
Changes in prevalence of, and risk factors for, lameness in random samples of English sheep flocks: 2004-2013.
in Preventive veterinary medicine
Winter JR
(2018)
Quantifying the beliefs of key players in the UK sheep industry on the efficacy of two treatments for footrot.
in Veterinary journal (London, England : 1997)
Description | Dichelobacter nodosus is the cause of footrot and its load increases before disease expression occurs. D. nodosus is detected on healthy feet for several weeks and on fresh footprints and fresh faeces on the floor of barns. There are no differences in the strains of D. nodosus in a flock and the severity of disease expressed. There are genetic differences in D. nodosus from different countries. There are differences in the bacterial species on the healthy and diseased feet. Hoof horn growth and wear is very seasonally dependent. Repeated cases of disease are more likely when sheep are treated by trimming feet rather than with antibiotic injection. |
Exploitation Route | Researchers working on footrot in sheep and veterinarians and farmers for practical outputs from the project |
Sectors | Agriculture Food and Drink |
URL | https://www.birmingham.ac.uk/research/microbiology-infection/research/microbial-epidemiology-farmed-livestock/index.aspx |
Description | Treatment of lame sheep - promotion of better treatment of lame sheep has been widely distributed through England and Wales as part of KE with EBLEX and HCC. Policy - the research was used by the Farm Animal Welfare Committee in an Opinion on Lameness in Sheep and target reductions in lameness were set Society and education - Results have been used to fund two further studentships |
First Year Of Impact | 2006 |
Sector | Agriculture, Food and Drink,Education |
Impact Types | Societal Economic |
Description | Cited in Farm Animal Welfare Council |
Geographic Reach | National |
Policy Influence Type | Citation in other policy documents |
Impact | Some evidence that prevalence of lameness in sheep has fallen |
Description | Development of new information on control of footrot and lameness for AHDB Beef & Lamb |
Geographic Reach | National |
Policy Influence Type | Influenced training of practitioners or researchers |
Impact | Bulletin sent to all 16000 members of sheep Better Returns Programme in England Written by PhD CASE students and Green Impact - Reduction in the number of sheep becoming lame, better health and productivity, economic gain to farmers |
URL | http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/07/BRP-Focus-on-lameness.pdf |
Description | Lecture to farm animal vet students on management of footrot |
Geographic Reach | National |
Policy Influence Type | Influenced training of practitioners or researchers |
Impact | 70 students attended the talk and heard new information on management of footrot and lameness |
Description | On farm event to 28 farmers of one veterinary practice in worcestershire |
Geographic Reach | Local/Municipal/Regional |
Policy Influence Type | Influenced training of practitioners or researchers |
Impact | the 28 farmers had new information on how to manage footrot and lameness in sheep |
Description | Technology exchange event to farmers Feb 2016 |
Geographic Reach | National |
Policy Influence Type | Influenced training of practitioners or researchers |
Impact | 67 farmers attended the one day event, 81% stated they would change management of footrot as a result of what they heard |
Description | BBSRC CASE studentship |
Amount | £70,000 (GBP) |
Organisation | Biotechnology and Biological Sciences Research Council (BBSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2009 |
End | 09/2013 |
Description | BBSRC-GCRF |
Amount | £150,000 (GBP) |
Funding ID | BBSRC-GCRF-IAA/22 |
Organisation | Biotechnology and Biological Sciences Research Council (BBSRC) |
Sector | Public |
Country | United Kingdom |
Start | 08/2016 |
End | 03/2017 |
Description | Development, testing and roll out of an online lameness recording system for sheep farmers |
Amount | £52,883 (GBP) |
Organisation | Animal Welfare Foundation |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 09/2016 |
End | 09/2017 |
Description | National roll out of an online lameness recording system for UK sheep farmers |
Amount | £28,599 (GBP) |
Organisation | Biotechnology and Biological Sciences Research Council (BBSRC) |
Sector | Public |
Country | United Kingdom |
Start | 11/2019 |
End | 02/2020 |
Description | Warwick Chancellor's award |
Amount | £70,000 (GBP) |
Organisation | University of Warwick |
Sector | Academic/University |
Country | United Kingdom |
Start | 09/2011 |
End | 09/2015 |
Description | AHDB |
Organisation | Agricultural and Horticulture Development Board |
Country | United Kingdom |
Sector | Charity/Non Profit |
PI Contribution | We work closely with AHDB Beef & Lamb providing summaries of research that are farmer friendly. Myself and PhD students attend farmer shows and events and talk to farmers. We work with AHDB to prepare knowledge exchange material |
Collaborator Contribution | AHDB are the CASE partner on a number of PhDs supporting industry relevant research on footrot and mastitis in sheep, giving students experience of an SME and talking to farmers to explain research |
Impact | http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/03/BRP-Reducing-lameness-manual-7-080316.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2014/08/brp-Decision-tree-for-lameness-270814.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/07/BRP-Focus-on-lameness.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2014/07/brp-Lameness080714.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2014/12/BRP-Udder-health-leaflet-181214.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/07/BRP-plus-Understanding-mastitis-in-sheep-180716.pdf |
Start Year | 2006 |
Description | AHDB |
Organisation | Agricultural and Horticulture Development Board |
Country | United Kingdom |
Sector | Charity/Non Profit |
PI Contribution | We work closely with AHDB Beef & Lamb providing summaries of research that are farmer friendly. Myself and PhD students attend farmer shows and events and talk to farmers. We work with AHDB to prepare knowledge exchange material |
Collaborator Contribution | AHDB are the CASE partner on a number of PhDs supporting industry relevant research on footrot and mastitis in sheep, giving students experience of an SME and talking to farmers to explain research |
Impact | http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/03/BRP-Reducing-lameness-manual-7-080316.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2014/08/brp-Decision-tree-for-lameness-270814.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/07/BRP-Focus-on-lameness.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2014/07/brp-Lameness080714.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2014/12/BRP-Udder-health-leaflet-181214.pdf http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/07/BRP-plus-Understanding-mastitis-in-sheep-180716.pdf |
Start Year | 2006 |
Description | Animal Welfare Research Network (AWRN) |
Organisation | University of Bristol |
Department | Advanced Composites Centre for Innovation and Science (ACCIS) |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Professor Laura Green is a co-investigator on the AWRN |
Collaborator Contribution | on the organising committee for the network. In 2016, organised a speed dating session at the first event In 2017, speaking on grant writing skills at the annual meeting In 2017, organised for neuroscientists to speak at an interdisciplinary workshop between neurobiology and welfare |
Impact | none |
Start Year | 2016 |
Description | Presentation to Lleyn pedigree sheep breeder's AGM |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Industry/Business |
Results and Impact | Presentation on managing footrot and mastitis in sheep |
Year(s) Of Engagement Activity | 2016 |
URL | http://www.lleynsheep.com/ |