safeguarding quarterly report small ruminant diseases...overview 2 issues & trends 4 horizon...

Emerging Threats Quarterly Report

Safeguarding public and

animal health

Small ruminant diseases

Annual Report: Quarter 4 2014

Date: February 2014

VIDA diagnoses are recorded on the APHA FarmFile database and SAC Consultancy: Veterinary Services LIMS database and comply with agreed diagnostic criteria against which regular validations and audits are undertaken. The investigational expertise and comprehensive diagnostic laboratory facilities of both APHA and SAC C VS are widely acknowledged, and unusual disease problems tend to be referred to either. However recognised conditions where there is either no diagnostic test, or for which a clinical diagnosis offers sufficient specificity to negate the need for laboratory investigation, are unlikely to be represented. The report may therefore be biased in favour of unusual incidents or those diseases that require laboratory investigation for confirmation. APHA VICs have UKAS Accreditation and comply with ISO 17025 standard. SAC C VS have UKAS accreditation at their central diagnostic laboratory and at the Aberdeen, Edinburgh, Perth, Ayr, Dumfries, Inverness, St Boswells and Thurso Disease Surveillance Centres which comply with ISO 17025 standard. From September 2014 APHA contracted the services of third party Post Mortem providers. During October to December 2014, these services were provided by the Royal Veterinary College, the University of Bristol and SACCVS. These providers contribute to the VIDA diagnoses recorded on the APHA FarmFile database and comply with agreed diagnostic criteria. To achieve a VIDA diagnosis, all testing must be carried out by a laboratory with ISO 17025 accreditation.

Contents page

Overview 2

Issues & Trends 4

Horizon Scanning 7

New & Emerging Diseases 8

Changes in disease patterns and risk factors 10

Unusual diagnoses 19

APHA staff Small Ruminant publications 20

Other publications 21

Highlights

Contagious Agalactiae 5

BTV in Europe 7

Post-weaning Encephalopathy 19

Suspected Neuronal Storage Disease 20

GB Small Ruminant Disease Surveillance Quarterly report

Oct – Dec 2014 Date 16th February 2015

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INTRODUCTION

This report contains analysis of disease data from APHA and SAC Consulting: Veterinary Services (SAC C VS) division of the Scottish Rural College (SRUC) from samples submitted for diagnosis to regional laboratories in the 4th quarter of 2014 compared to the equivalent quarter of previous years and examination of Annual trends. It aims to identify emerging small ruminant disease related threats. The production of the report is underpinned by a large quantity of surveillance data and information, compiled as part of the Defra Animal and Plant Health Directorate. Further information can be found on the APHA Vet Gateway: http://ahvla.defra.gov.uk/vet-gateway/surveillance/reports.htm

OVERVIEW

Weather:

In October the weather was unsettled and wet and remained so through most of the month, interspersed with short periods of drier weather. With winds frequently from the south, well above average temperatures were recorded. The remnants of Hurricane Gonzalo caused strong winds and localised heavy rainfall, over the northern half of the UK. November was also unsettled. Low pressure was often over or to the west of the UK for the first half of the month bringing rain and strong winds at times. It was unseasonably mild with above average temperatures. Sightings of frog spawn were reported in Cornwall. In December rainfall totals were mostly below average in the south and east. A vigorous Atlantic low pressure system brought wind gusts of up to 70 mph across the north of the UK on 10th December and caused widespread power & transport disruption in Scotland. On Boxing Day there were some snowfalls in Wales & Northern England with the lowest UK temperature readings of the year recorded at New Year. Industry

A robust lamb trade in December saw 181.5p/kg achieved, the SQQ moving up over 30p since the low point of the year in late September. The deadweight trade prices for December SQQ reached 422.7p/kg, up almost 70p over the past three months and around 25p/kg higher than the same time in 2013. At 1.17 million head, UK lamb slaughtering’s in November were significantly ahead of year earlier levels. However, although forage supplies have been abundant this year, quality may have been relatively poor and lambs slow to finish. Nevertheless the level of throughputs supports the expectation of a bigger lamb crop this year. The number of store lambs sold through GB auction markets, was up 21% on last year between July and November, with many of the additional 220,000 animals involved yet to be finished. The cull ewe trade average at GB auction marts was over £72 per head, up around £22 over the past three months and at the same time last year (Fig 1). UK adult sheep slaughtering’s in November were back 19% at 134,000 head. This takes the adult kill in 2014 so far to 1.68 million head, back 11% year on year. UK sheep meat imports were similar to 2013 over the summer but they have subsequently fallen. Australia filled its EU import quota early, while the New Zealand new season got off to a slow start. Both exporters have struggled to fulfil orders for the Christmas market, which has

http://ahvla.defra.gov.uk/vet-gateway/surveillance/reports.htm



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seen UK buyers switching to domestic lamb instead. UK sheep meat imports in October were behind year earlier levels again. Looking to the future, it would seem that Australia and New Zealand will continue to dominate red meat trade with China, especially in the case of sheep meat. Lower tariff rates as a result of FTAs contribute to their competitive advantage. The UK currently has no access to the Chinese market for beef and lamb and it would clearly help if the EU could also agree an FTA or something similar with China

Fig 1: GB Live weight Lamb SQQ and GB cull ewe averages

. Source EBLEX Cattle and Sheep Market Update http://www.eblex.org.uk/wp/wp-content/uploads/2014/12/Cattle-sheep-market-update-Dec-231214.pdf

Fallen Stock The following graphs (Fig 2) plot the fallen stock figures for England Scotland, Wales and Northern Ireland, as recorded by National Fallen Sock Company (NFSCo). The figures do not include all collections, just those put through the NFSCo scheme. Consequently conclusions should be drawn according to the trends, rather than the specific figures. From these we can see that sheep mortality for 2014 has returned to average levels after the bad weather spike in 2013. The graphs below are taken from the NFSCo Annual Report 2014 http://www.nfsco.co.uk/news-detail.php?NewsID=57

http://www.eblex.org.uk/wp/wp-content/uploads/2014/12/Cattle-sheep-market-update-Dec-231214.pdf

http://www.nfsco.co.uk/news-detail.php?NewsID=57

http://www.nfsco.co.uk/news-detail.php?NewsID=57



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Fig 2: Fallen Stock Trends GB

ISSUES & TRENDS From September 2014 AHVLA introduced additional providers of subsidised post-mortem examinations (PMEs), together with new carcase collection sites and subsidised carcase transport arrangements, to support veterinary businesses in their diagnostic work. These include the Royal Veterinary College (RVC) serving an area of the East of England, University of Bristol serving an area of the South West England and SAC St Boswells serving an area of the North East of England. At the time of writing this report, submissions had been received at all centres, VIDA diagnostic criteria applied and incorporated into the database disease analysis review. From February 2015 other providers of subsidised post-mortem examinations will commence and include: the University of Surrey operating out of sites located in the North West, South West, South East, West Midlands and East of England and with Iechyd Da providing services to practitioners in Wales and operating initially out of Aberystwyth. TB in sheep and Goats The statistics for Bovine tuberculosis (BTb) in non-bovine species are reported on www.gov.uk https://www.gov.uk/government/statistical-data-sets/other-tb-statistics. At the time of writing the latest report is for the second quarter of 2014 where 1 of 8 sheep and 16 of 16 goats tested had returned a positive culture. Due to the long culture period for BTb there is always a lag in reporting cases. The link will show reports as they are compiled and added.

https://www.gov.uk/government/statistical-data-sets/other-tb-statistics



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TSE’s in sheep and goats Active disease surveillance European law requires all Member States to carry out active disease surveillance for bovine spongiform encephalopathy (BSE) in cattle, and scrapie in sheep and goats. This data is used to determine the TSE disease status of each country. Compulsory Scrapie Flocks Scheme Since 2004, disease control measures require sheep flocks and goat herds to join the Compulsory Scrapie Flocks Scheme (CSFS) when a case of scrapie is confirmed. Subsequent cases of scrapie in these flocks and herds are reported separately. APHA provides summary statistics on the number of submissions tested and cases found through the CSFS testing routes (initial cull, annual cull and fallen stock) in Great Britain. Passive disease surveillance Passive disease surveillance takes place when an animal with clinical signs suspicious of a TSE disease is reported to an APHA office, and further investigation determines whether the animal was affected by BSE or scrapie. Current statistics for Scrapie are available on www.gov.uk https://www.gov.uk/government/statistics/active-tse-surveillance-statistics Encouragingly there have been no reports of classical scrapie in sheep in 2014, although 10 cases of atypical scrapie were reported. In goats 21 were confirmed with classical scrapie. Contagious Agalactiae Mycoplasma agalactiae the causative organism of contagious agalactia (CA), an OIE listed and notifiable disease, was detected in one of four goats imported into Wales from France. This was detected in a post–import test and effective action to control the disease risk was successfully implemented. The case was reported to APHA in October and affected and in-contact goats were euthanased on 25th October 2014. Any suspicion of CA during a farm visit or other investigation must be immediately reported to Animal Health (APHA). Mycoplasma agalactiae is the main causative organism of contagious agalactia, but other exotic Mycoplasma species which are also reportable, cause similar clinical conditions. This includes Mycoplasma capricolum subsp. capricolum; M. putrefaciens and M. mycoides subsp. capri which now incorporates M. mycoides subsp. mycoides large colony. Surveillance for CA is pro-active and relies on submissions of samples from cases showing signs of mastitis, or udder abnormality, which are tested by APHA. This work is funded by Defra. In addition to this passive surveillance all imported animals from countries that have the disease are post import tested.

Diagnostic submissions:

Sheep non-carcase submissions (Table1) across GB decreased by 5% this quarter compared to the previous quarter in 2013 but increased by 22% to SAC C VS investigation centres. The number of sheep carcases submitted to APHA for this quarter was equivalent to 2013 and increased to SAC C VS centres by 8% compared to the previous quarter in 2013. A comparison of Annual Sheep and Goat submission is shown in Fig 4.

http://www.gov.uk/

https://www.gov.uk/government/statistics/active-tse-surveillance-statistics



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Table 1: Sheep submissions 2014 Quarter 3

(Comparison % change to previous year shown in brackets) Non Carcase Submissions Carcase Submissions

Oct-Dec APHA SAC Total APHA SAC Total GrTotal

2014 611 (↓5%) 465 (↑22%) 1,076 (↑5%) 211 185 (↑8%) 396 (↑4%) 1,472 (↑5%)

2013 645 379 1,024 211 171 382 1,406

2012 799 361 1,160 328 271 599 1,759

2011 621 295 916 255 189 444 1,360

2010 630 286 916 223 137 360 1,276

Fig 4: Annual Sheep & Goat submissions 2014

For goat diagnostic submissions to APHA and SAC C VS there was a decrease of 10% in non-carcase submissions (Table 2). The number of goat carcase submissions is lower compared with sheep carcase submissions nevertheless the number of goat carcase submissions remains at the same level over the last 5 years and the number submitted to SAC C VS have increased from an average of 3 during 2010 - 2011 to 7 in 2014. With low numbers it is difficult to interpret this as any general trend.

Table 2: Goat submissions 2014 Quarter 4 (Comparison % change to previous year shown in brackets)

Non Carcase Submissions Carcase Submissions

Oct-Dec APHA SAC Total APHA Scotland Total GrTotal

2014 100 (↓10%) 42 (↓10%) 142 (↓10%) 22 7 29 171

2013 111 46 157 22 3 25 182

2012 94 45 139 22 4 26 165

2011 90 31 121 13 3 16 137

2010 78 23 101 22 3 25 126



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HORIZON-SCANNING

Bluetongue virus (BTV) Bluetongue (BTV-4 and BTV-1) has continued to cause outbreaks across the southern EU Member States and bordering countries. Many of these countries are now in vector free period, and it will several weeks before we know if the virus has over wintered. Wild animals have become infected with bluetongue in Bulgaria, resulting in deaths in deer and wild sheep. The sequence data provided by the Pirbright Institute Community Reference Laboratory show that bluetongue is moving around the southern Mediterranean region still (Fig 3) and therefore awareness should be maintained for new incursions or spread through vector movement. The situation in Greece, Bulgaria and possibly wider in the Balkan region does not significantly increase the risk of disease incursion to the UK, which remains at “low” or “rare but does occur”. APHA undertake surveillance for BTV by post import testing of all sheep and goats imported from countries that have BTV. Our Import team report that there have been no sheep or goats imported from countries affected by BTV during 2014. Control measures for trade in live animals are in place in line with the Bluetongue Regulation, EC/1266/2007. The UK has published an updated Bluetongue disease control strategy which is available on the UK.gov website: http//www.gov.uk/government/publications/bluetongue-gb-disease-control-strategy

Fig 3: Current BTV outbreaks in Europe 2014

https://www.gov.uk/government/publications/bluetongue-gb-disease-control-strategy



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SCANNING SURVEILLANCE FOR NEW AND EMERGING DISEASES IN SMALL RUMINANTS

Monitoring the trends in diagnoses of known diseases cannot, by definition, detect either new diseases or changes in endemic diseases that would prevent a diagnosis from being reached (for example a change in the pathogen that compromised the usual diagnostic test). Such new or emerging diseases would probably first be detected by observation of increased numbers of submissions for clinical and/or pathological syndromes for which a diagnosis could not be reached in the normal way. Submissions for which no diagnosis is reached (DNR) despite testing deemed to allow reasonable potential for a diagnosis to be reached are regularly analysed to look for increases in undiagnosed disease which could indicate the presence of a new or emerging disease. Undiagnosed disease submissions are summarised broadly by the clinical presentation of disease and, once this has been determined by further investigation, the body system affected. Both groups are investigated and trends in the levels are compared over time. Data recording by APHA and SAC was harmonised from 2007. In this report GB data from the third quarter of 2014 is compared with the data from the equivalent quarter in 2013 and has also been compared with pooled data for the five previous years. Supplementary analysis of APHA DNR data is also undertaken using an early detection system (EDS). This uses a statistical algorithm to estimate an expected number of DNR reports and a threshold value. If the current number of DNR reports exceeds the threshold (i.e. exceedance score>1), this indicates that the number of reports is statistically higher than expected.

Analysis of Diagnosis Not Reached (DNR)* SHEEP Annual:

There was no significant change in the overall %DNR; 20.5% for prior years compared to 19.8% for 2014.

There were statistically significant increases for the syndrome and presenting sign “skin” for GB and SAC when comparing the annual figures for 2014 with previous years (Table 3 & 4).

Quarter 4:

There was a significant reduction in overall %DNR for GB for the 4th quarter 2014 (10.7%) compared to equivalent previous quarters (13.6%).

There was an equivalent significant reduction for APHA figures (12.6 to 7.1%). The changes for SAC (15.5 to 15.9%) are not statistically significant.

There were significant increases for the presenting signs “Healthy”, “Recumbent” and “Skin” for GB (Table 3 & 4).

The early detection system showed no exceedance of DNR threshold values for the 4th quarter 2014 when compared to data from the previous 5 years for submissions received at APHA laboratories in England and Wales. GOAT Annual:

There was no significant change in the overall %DNR; 20.6% for prior years compared to 13.8% for 2014 and there were no significant increases for any of the presenting signs or syndromes.

Quarter 4:

There was no significant change in the overall %DNR; 17.3% for prior years compared to 8.8% for 2014 and there were no significant increases for any of the presenting signs or syndromes.



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Analysis of DNR by syndrome and presenting sign

Table 3: ANNUAL - Syndromes / presenting signs showing a significant annual increase in %DNR for sheep for 2014 compared to previous years for GB

Table 4: QUARTERLY - Syndromes / presenting signs showing a significant increase in %DNR

for sheep for Q4 Oct - Dec 2004-2014 Presenting sign “Healthy” in sheep Significant increase in GB figures for quarter 4 as shown in table 2.There was an equivalent significant increase for SAC figures. The numbers involved are very small and unlikely to indicate a new or re-emerging threat. Presenting sign “Recumbent” in sheep Significant increase in GB figures for quarter 4 as shown in table 2.There was no equivalent significant increase for APHA or SAC figures. The numbers involved are very small and unlikely to indicate a new or re-emerging threat. Syndrome and Presenting sign “Skin” in sheep Significant increases in annual GB figures shown in table 1 and for quarter 4 as shown in table 2. There were equivalent significant annual and quarterly increases for SAC figures but not for APHA figures. Further analysis of the 21 SAC submissions involved for this quarter, revealed that in only 6 of these cases were there “No apparent reason for not reaching a diagnosis” and they are a mixture of different types of lesions with no obvious consistent pattern to indicate the possibility of a new or emerging disease.

* When a VIDA diagnostic code is assigned to a specific submission, the decision has to be made if it meets the stated diagnostic criteria. If the criteria are not met, it is marked as “Diagnosis Not Reached” or DNR. If it is a DNR, the next step is then to decide if this was due to limited testing or if reasonable testing had been done. If it is deemed that reasonable testing had been done, there may be reasons why a diagnosis could not be reached and this should be recorded and can include inappropriate disease phase, treatment, inconclusive results, or other reasons. Typical examples of such submissions include; coccidiosis cases where speciation was not done and Johne’s cases in live sheep where the test results may be inconclusive. However, in some cases there is no apparent reason to explain why a diagnosis could not be reached and these are the submissions, if present in significant numbers, which may indicate new and emerging disease.

SHEEP Prior years (2008 - 2013) 2014

Syndrome

Skin 17.6% (402/2291) 30.1% (65/216)

Presenting sign

Skin 16.4% (351/2136) 27.1% (54/199)

SHEEP October to December prior years (2008 - 2013)

October to December 2014

Presenting sign

Healthy 3.7% (3/82) 30% (3/10)

Recumbent 10.6% (12/113) 33.3% (3/9)

Skin 15.8% (77/487) 37.9% (22/58)

Syndrome

Skin 16.1% (84/522) 27.1% (54/199)



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CHANGES IN DISEASE PATTERNS AND RISK FACTORS

This section of the report gives information on occurrence of selected diseases. The data originate from submissions and are summarised and presented according to the diagnosis reached and assigned as a VIDA code. Our charts show the number of diagnoses (numerator) as a proportion of the number of submissions in which that diagnosis was possible (denominator), for all of GB, England & Wales and for Scotland. The bars indicate the 95% confidence limits. Note that the y-axis scale of the charts varies and therefore care must be taken when comparing individual charts.

SYSTEMIC DISEASE Q4: No significant GB or APHA changes. Bibersteinia trehalosi septicaemia Bibersteinia trehalosi septicaemia cases in lambs, very often with concurrent PGE, were reported by most centres. In some cases the history indicated full and appropriate vaccination, but it is accepted that vaccination does not provide 100% cover for this disease, especially in the face of severe challenge or when concurrent diseases such as PGE is present. Systemic Bibersteinia trehalosi infections typically affect six-nine month old lambs with outbreaks usually occurring between October and December. Control is best achieved by vaccination and it is encouraged to report vaccine failures to the VMD. There was an increase in submissions (55 for 2014 compared to 36 for 2013) diagnosed with this condition in Q4 for SAC and APHA, but the increases were not significant (Fig 5).

Fig 5: Incidents of B.trehalosi in Sheep as a % of diagnosable submissions Q4

(Vertical bars represent 95% confidence limits)

Annual: No statistically significant changes for diseases examined. ENTERIC DISEASE No statistically significant changes in Quarter 4 for diseases examined. Annual: Johne's disease There was a significant increase for submissions diagnosed with Johne’s disease, with 109 this year compared to 84 in 2013 (Fig 6). It is likely that increased awareness of this condition and the availability of the more sensitive PCR testing and the ELISA test have contributed to this increase.



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Fig 6: Annual incidents of Johne’s disease for GB as a % of diagnosable submissions 2004-2014


REPRODUCTIVE DISEASES No statistically significant changes in Quarter 4 for diseases examined but few abortions happen in Q4 with the majority recorded in the 1st quarter of the year. Annual: There was a significant increase for GB abortion submissions diagnosed with Chlamydophila fetopathy (Enzootic Abortion in Ewes), with 387 this year compared to 274 in 2013 (Fig 7). It is at a similar level to figures from 2011 and 2007. A similar significant increase was seen for APHA submissions with 300 submissions diagnosed in 2014 compared to 217 in 2013. Fig 7: Annual incidents of Chlamydophila fetopathy for GB as a % of diagnosable submissions 2004-2014


RESPIRATORY DISEASES No statistically significant changes in Quarter 4 for diseases examined. Annual: Ovine Pulmonary Adenomatosis OPA There was an increase in the incidents of Ovine Pulmonary Adenomatosis (OPA)/ Jaagsiekte in sheep in Scotland on an annual basis in 2014. This trend was seen across all quarters. In total 78 cases were diagnosed in 2014 compared to an average of 67 over the previous 5 years (Fig 8). Of these 78 cases, 57 were in Scotland. However as a percentage of diagnosable submissions this is not statistically significant.



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OPA is a contagious tumour of the lungs of sheep. It is also commonly known as Jaagsiekte, ovine pulmonary carcinoma or sheep pulmonary adenomatosis. OPA is generally considered a chronic wasting disease with progressive respiratory distress leading to emaciation, but it may be that early lung lesions predispose to secondary bacterial pneumonia causing sudden death despite antibiotic treatment. The disease may be grossly under-reported because few deaths are investigated on sheep farms. Disease transmission is facilitated by close confinement such as indoor housing. Effective control, and possible disease eradication, has been hampered by the lack of a suitable diagnostic test or vaccine. The Moredun Institute conducts research into the development of diagnostics for OPA as detailed in the following article: Scott, P, Griffiths, D, Cousens. C. (2013) Diagnosis and control of ovine pulmonary adenocarcinoma (Jaagsiekte) In Practice2013. 35:382-397

The Food Standards Agency has identified the need for a more effective, risk based and proportionate approach to meat controls. As well as protecting public health, new approaches should protect animal health and welfare. A study has been commissioned to investigate ways of improving the effectiveness and efficiency of meat controls by identifying key FCI and CCIR data, designing an improved FCI/CCIR model and carrying out a cost benefit analysis. One of the aims of this study is to assist producers and their veterinarians to improve production systems, resulting in better public and animal health and animal welfare standards. This may include surveillance for sheep disease for example liver fluke and lung pathology which could inform the incidence of key disease which affect production. A Pilot study funded by EBLEX and carried out during 2012 – 2013 assessed the diagnostic quality of post-mortems in fallen sheep (Lovatt & Strugnell 2013). Six of 106 ewes (5.6%) were diagnosed with OPA as the cause of death on gross pathology and confirmed with histopathology, demonstrating that it is possible to identify this disease in fallen stock. During 2014 EBLEX supported a diagnostic post-mortem service to farmers on fallen stock delivered to a fallen stock centre in Hamsterley, County Durham. The results of this service will be reported by EBLEX in 2015. Lovatt, F.M. & Strugnell, B.W. (2013) An observational study involving ewe postmortem examination at a fallen stock collection centre to inform flock health interventions. Veterinary Record 172 (19), 504.

Figure 8: Annual incidents of OPA for GB as a percentage of diagnosable submissions 2004-2014


Laryngeal Chondritis There were no significant changes in the number of diagnoses of Laryngeal Chondritis during this quarter of 2014; however examination of the annual data showed an overall increase in



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cases this year when compared to 2013. There was an increase in Scotland (15 cases) for 2014 compared to previous years (average 7.6) (Fig 9). In total there were 25 cases diagnosed in GB compared to an average of 17 in the previous five years. The following breeds were represented Texel & Texel cross 18, Beltex & Beltex Cross 4, Suffolk 1, Welsh Mountain 1 and cross bred 1.

Fig 9: Regional distribution of Laryngeal Chondritis in GB 2014

Maedi Visna This disease was mentioned a few times in the farming press with concerns raised by some veterinarians that the prevalence of this disease may be on the increase. Although the GB VIDA data show a small increase compared to 2013 (Fig 10), there were only six submissions where this disease was diagnosed in 2014. It is however very likely that this disease is underdiagnosed in GB as it is not always obvious in a flock unless large numbers are affected and it requires targeted testing of older sheep that, in many cases, may just get culled without further investigation.

Figure 10: Annual incidents of Maedi Visna for GB as a percentage of diagnosable submissions 2004-2014


SRUC offer a flock health scheme for MV and in 2014 identified a worrying number of infected flocks. The disease progresses slowly, with wasting and increasing respiratory distress as the main signs, signs rarely seen in sheep less than 2 years old and most common in sheep over 4 years old. Screening was performed in flocks where there were suspicions of MV infection and in 23% (seven of the 31 of the flocks tested) these suspicions unfortunately proved to be correct. The owners of six of these flocks had reported seeing signs including breathlessness in adult sheep, lameness and swollen joints.



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SRUC recommends concerned flock masters should target test 12 older, thinner animals using the MV diagnostic test to indicate if losses are due to the disease. A similar approach should be taken to sheep showing ill-thrift or reacting badly to exercise.

For further information on Maedi Visna Flock Health Schemes, visit SRUC pages on the Premium Sheep & Goat Health Scheme (PSGHS) and PSGHS Maedi Visna.

NERVOUS DISEASES Cerebro-cortical necrosis (CCN) There were no significant changes in the number of diagnoses of CCN during this quarter of 2014; however examination of the annual data showed an overall increase in cases this year when compared to 2013. 37 cases (1.89%) were recorded in 2014 with only 25 (0.97%) recorded in 2013. This increase was mainly seen by APHA who reported nearly twice as many cases this year than last (21 cases (1.97%) in 2014 compared to 12 (0.81%) in 2013).

Fig 11: Incidents of CCN in Sheep as % of diagnosable submissions 2004-2014


Listerial Encephalitis

No significant Q4 or annual changes/trends.

Louping ill Compared to the same quarter in 2013 there has been a significant decrease in diagnoses of Louping ill as a percentage of diagnosable submissions in 2014 (1.81% compared to 0.22%) (Fig 12). Although diagnoses by APHA remained relatively static, there was a notable absence of cases diagnosed by SAC this quarter; 8 cases (4.35%) in 2013 compared to zero cases this year.

Fig 12: Incidents of Louping in Sheep as % of diagnosable submissions in Q4

http://www.sruc.ac.uk/info/120113/premium_sheep_and_goat_health_schemes

http://www.sruc.ac.uk/info/120113/premium_sheep_and_goat_health_schemes/511/diseases_covered/2



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Looking at the data annually, overall, the number of recorded cases in GB has remained relatively static between 2013 and 2014 (Fig 13), but interestingly, there has been a reversal in case numbers between APHA and SAC. During 2013 the increase in cases was seen in Scotland, however this year the increase was most notable in England with APHA recording double the number of cases this year (12 cases) when compared to 2013 (6 cases). It is not unusual to see yearly fluctuations in Louping ill cases as tick activity is strongly correlated with climatic conditions.

Fig 13: Incidents of Louping Ill in Sheep as % of diagnosable submissions 2004 – 2014


MUSCULO-SKELETAL DISEASES Arthritis due to Streptococcus dysgalactiae subsp dysgalactiae There was an overall annual decrease in cases of arthritis due to Streptococcus dysgalactiae this year when compared to 2013 (19 cases vs 50 cases). APHA recorded the biggest decrease, particularly during Q1 and Q2, with a total of 15 cases reported in 2014 compared to 43 in 2013 (Fig 14). This decrease is most likely associated with the better weather conditions experienced during spring 2014, which meant that ewes and lambs could be turned out to grazing earlier rather than being housed for long periods.

Fig 14: Incidents of Arthritis – Strep dysgalactiae as % of diagnosable submissions 2004 - 2014


Arthritis due to Erysipelas Five cases of arthritis due to Erysipelothrix rhusiopathiae were recorded this quarter. Typical clinical histories included poor condition with chronic lameness and a stilted stiff gait with a



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tendency to lie down. The condition was mainly observed in weaned lambs between seven and nine months of age. Two live lambs from one case were submitted to Penrith VIC. Both lambs had palpable heat and periarticular swelling in the carpus and stifle joints. Post-mortem examination found turbid excess fluid within the elbow joints, carpal joints, tarsal joints, stifles, metacarpophalangeal and metatarsophalangeal joints of one lamb with pannus formation within the larger joints, particularly the stifles. There was marked periarticular thickening around elbow and stifle joints. The atlanto occipital joint also contained turbid red-tinged fluid. The second lamb had similar pathology affecting carpal joints, metacarpophalangeal and metatarsophalangeal joints, tarsal joints and stifle joints. Both lambs had enlarged oedematous prescapular lymph nodes. Bacteriological cultures identified Erysipleothrix rhusiopathiae in pure growth from samples of joint fluid from multiple sites. In addition serological testing on blood taken prior to euthanasia found very high antibody titres by SAT (High Positive > 1/20480). The gross findings were typical of severe septic polyarthritis. E.rhusiopathiae is a soil borne organism and may gain access through any open wound / abrasion, however it is a less commonly diagnosed cause of inflammatory joint disease in sheep now as many flocks no longer dip and dips contain bactericides.

URINARY DISEASES; BLOOD, LYMPH AND CIRCULATORY DISEASES; SKIN DISEASES; SYSTEMIC DISEASE No statistically significant changes in Quarter 4 for diseases examined.

GOAT DISEASES

Annual: Johnes disease There were no significant changes in the number of diagnoses of Johnes disease in goats during this quarter of 2014; however examination of the annual data showed an overall increase in cases this year when compared to 2013. This increase was seen in England and Wales in 2014 with 52 case compared to an average of 40 for the preceding 5 years (Fig 15). However as a percentage of diagnosable submissions this was not statistically significant.

Fig 15: Regional distribution of Johnes disease in Goats in GB 2014



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PARASITOLOGY

Parasitic Gastroenteritis (PGE) There was a significant increase in the incidents of PGE diagnosed in the fourth quarter of 2014 in England and Wales compared to the same period in the previous ten years (Fig 16). However incidents in Scotland were similar to the previous year. It is likely that the generally dry and warm summer in 2014 (particularly June and July) led to poor exposure of lambs to gastro-intestinal parasites until the autumn and winter. Mixed genera infecting the lambs were often present. Trichostrongylus spp, Teladorsagia spp, Nematodirus spp and Haemonchus spp were the genera recorded in these diagnoses where gastro-intestinal tract washes were carried out. PGE due to nematodirosis and PGE due to haemonchosis were also recorded and coded separately if these were thought to be the predominant genera. There was evidence of animals grazing severely infected pastures with large numbers of immature nematodes also being detected. Suspicions of anthelmintic resistance to all three older classes of anthelmintics were raised by all investigation centres because of recent reported treatment that appeared not to be effective. Vitamin B12 (cobalt) deficiency was also identified concurrently in some cases. There is clearly a need for the adoption of SCOPS advice and development of Flock Health plans to identify potential Anthelmintic resistance and appropriate worming strategies.

Fig 16: Incidents of PGE in sheep as a % of diagnosable submissions Q4


Incidents of PGE nematodirosis and PGE due to haemonchosis did not show significant differences from previous years.

Acute fasciolosis There was a very low incidence of acute fasciolosis in Q4 2014, following the trend from the third quarter (Fig 17). The very dry September could have meant a reduced number of infected snails, and less distribution of cercariae onto the pasture from them, to cause acute fasciolosis.



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Figure 17: Incidents of Acute Fasciolosis for GB as a % of diagnosable submissions Q4


Annual: The annual VIDA data clearly demonstrates the effect of weather on incidence of acute fasciolosis. 2012 was very wet, with a high incidence of this disease in the autumn of that year (Fig 18). Two years of comparatively less rainfall has seen a significant fall in percentage diagnosis since then.

Figure 18: Annual incidents of Acute Fasciolosis as a % of diagnosable submissions 2004-2014


Chronic fasciolosis The incidence of fasciolosis in the fourth quarter and 2014 as a whole continued a downward trend as for acute fasciolosis (Fig 19 & 20).

Figure 19: Incidents of Chronic Fasciolosis in Sheep as a percentage of diagnosable submissions in Q4




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Figure 20: Annual incidents of Chronic Fasciolosis as a % of diagnosable submissions 2004 - 2014


UNUSUAL DIAGNOSES Hemlock poisoning and Tick Borne Fever Shrewsbury investigated mortalities in a group of 420 recently weaned ewes. The ewes had been treated with a cypermethrin pour-on and moved onto open hillside. The group were later moved into a closed area with bracken. Ten days later 12 ewes were found dead and 13 others were ill with several recumbent and paddling. On closer inspection dilated pupils, mild hyperaesthesia, and a fine tremor were noted. At post mortem examination several live ticks were found on the carcase. Inclusion bodies were detected in blood smears and PCR for Anaplasma phagocytophilum confirmed Tick Borne Fever (TBF). Histological examination of organs provided evidence of multisystemic inflammation perhaps associated with low level septicaemia. TBF causes initial pyrexia and subsequent immunosuppression. However histology of the heart described lesions that could be compatible with intoxication. The group of sheep were immediately moved off the field but mortalities continued with two to three sheep dying every day. A VIO visited the farm and while some improvement had occurred after treatment with oxytetracycline, deaths continued. The field was examined and several Umbelliferae plants were present which had the majority of their stems and leaves missing. Plants were collected and sent to the SAC for examination. A ewe that had displayed neurological signs was submitted for post-mortem examination. Extensive histological examination showed damage to the nerves of the spinal cord potentially related to a neurotoxic agent.

Fig 17: Conium maculatum Inflammation was evident in a wide variety of organs including the gastrointestinal tract, particularly in the fore stomachs. This was likely to be due to secondary infection following gastrointestinal atony resulting from impaired transmission of nervous stimulus after ingestion of toxins. The presence of hemlock (Conium maculatum Fig 17) was confirmed by SAC. The overall presentation of the case suggested that hemlock poisoning had occurred in addition to the Tick Borne Fever.



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Post-weaning Encephalopathy This condition was diagnosed on two occasions this quarter by Penrith and Starcross VICs. The case investigated by Penrith involved a group of 200, six-to-seven-month old Texel cross lambs of which 20 were in poor condition, depressed and one or two were reported to behave as if they were blind. Affected lambs often became moribund and died. The lamb submitted was in poor condition and had reportedly displayed neurological signs. Gross post-mortem findings were unremarkable. A similar case history was reported by Starcross in which 30 lambs from a group of 100 were failing to grow as expected and showed nervous signs including blindness, head pressing, teeth grinding and recumbency. Three typical cases were submitted for post-mortem examination. In both cases histopathological examination of the brain confirmed the presence of a severe extensive subacute polioencephalopathy the distribution of changes consistent with post-weaning encephalopathy (putative water deprivation). A concurrent parasitic gastroenteritis and cobalt deficiency was also confirmed in the Starcross cases. This condition has been previously described; four outbreaks were the subject of a letter to the Veterinary Record which provides some useful background information. (‘Unusual encephalopathy in weaned lambs’ (2005) Veterinary Record. SFE Scholes et al, 24-31 December, page 853). Suspected Neuronal Storage Disease Wasting and nervous signs were the symptoms which were reported affecting nine in a group of 30 Easycare ewes while the other 70 Exlana sheep making up this flock of 100 were unaffected. The flock, kept outdoors on fern grazing, were treated with Combinex three months previously and were provided with mineral licks. The affected group started off with a staggering gait and depression, later needed assistance getting up and within three months from onset of signs showed recumbency and paddling. Four ewes were subsequently euthanized. One was submitted for post-mortem but unfortunately the method of euthanasia selected - captive bolt - damaged the brain at two points, compromising histopathological examination and interpretation. The investigation ruled out Listerial involvement, Gid, CCN and lead poisoning. To the extent possible however, histopathology observed an intracytoplasmic pigment accumulation consistent with neuronal storage disease (NSD), suggestive of either a genetic factor or exposure to toxic plants (e.g. Phalaris spp.).

APHA staff publications in relation to small ruminants

ADKIN, A, Jones, DL, Eckford, RL, Edwards-Jones, G, Williams, AP. (2014) A quantitative risk assessment for the safety of carcase storage systems for scrapie infected farms. Journal of Applied Microbiology 117 (4) 940-948. ARNOLD, M, ORTIZ-PELAEZ, A. (2014) The evolution of the prevalence of classical scrapie in sheep in Great Britain using surveillance data between 2005 and 2012. Preventive Veterinary Medicine 117 (1) 242-250. BANYARD, AC, Wang, Z, Parida, S. (2014) Peste des petits ruminants virus, eastern Asia (letter). Emerging Infectious Diseases 20 (12) 2176-2178. Cook, A, Dobbs, M, HINE, R. (2014) Provision of diagnostic postmortem examination services (letter). Veterinary Record 175 (19) 489.



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Krejciova, Z, Barria, MA, Jones, M, Ironside, JW, JEFFREY, M, GONZALEZ, L. (2014) Genotype-dependent molecular evolution of sheep bovine spongiform encephalopathy (BSE) prions in vitro affects their zoonotic potential. Journal of Biological Chemistry 289 (38) 26075-26088. Kumar, KS, Babu, A, Sundarapandian, G, Roy P, Thangavelu, A, Kumar, KS, Arumugam, R, Chandran, NDJ, Muniraju, M, Mahapatra, M, BANYARD, AC, Manohar, BM, Parida, S. (2014) Molecular characterisation of lineage IV peste des petits ruminants virus using multi gene sequence data. Veterinary Microbiology 174 (1-2) 39-49. Muniraju, M, Munir, M, BANYARD, AC, Ayebazibwe, C, Wensman, J, Zohari, S, Berg M, Parthiban, A, Mahapatra, M, Libeau, G, Batten, C, Parida, S. (2014) Complete genome sequences of lineage III peste des petits ruminants viruses from the Middle East and East Africa. Genome Announcements 2 (5) e01023-14. Muniraju, M, Munir, M, Pathiban, AR, BANYARD, AC, Bao, J, Wang, Z, Ayebazibwe, C, Ayelet, G, El Harrak, M, Mahapatra, M, Libeau, G, Batten, C, Parida, S. (2014) Molecular evolution of peste des petits ruminants virus. Emerging Infectious Diseases 20 (12) 2023-2033. PAYNE J, MURPHY A. (2014) Plant poisoning in farm animals. In Practice 36 (9) 455-465. VORDERMEIER, HM, Perez de Val, B, Buddle, BM, VILLARREAL-RAMOS, B, JONES, GJ, HEWINSON, RG, Domingo, M. (2014) Vaccination of domestic animals against tuberculosis: review of progress and contributions to the field of the TBSTEP project. Research in Veterinary Science 97 (Supplement) S53-S60. Morrison, AA, MITCHELL, S, MEARNS, R, Richards, I, Matthews, JB, Bartley, DJ. (2014) Phenotypic and genotypic analysis of benzimidazole resistance in the ovine parasite Nematodirus battus. Veterinary Research 45, 116 Other publications Monepantel resistance reported on Dutch sheep farms. Veterinary Record 175 (17) 418 ARNOLD, M, ORTIZ-PELAEZ, A (2014) The evolution of the prevalence of classical scrapie in sheep in Great Britain using surveillance data between 2005 and 2012. Preventive Veterinary Medicine 117 (1) 242-250 Kumar, KS, Babu, A, Sundarapandian, G, Roy. P, Thangavelu, A, Kumar, KS, Arumugam, R, Chandran, NDJ, Muniraju, M, Mahapatra, M, BANYARD, AC, Manohar, BM, Parida, S (2014) Molecular characterisation of lineage IV peste des petits ruminants virus using multi gene sequence data. Veterinary Microbiology 174 (1-2) 39-49 Angelidou, E, Kostoulas, P, Leontides, L (2014) Flock-level factors associated with the risk of Mycobacterium avium subsp. paratuberculosis (MAP) infection in Greek dairy goat flocks. Preventive Veterinary Medicine 117 (1) 233-241 Hegde, S, Hegde, S, Spergser, J, Brunthaler, R, Rosengarten, R, Chopra-Dewasthaly, R. (2014) In vitro and in vivo cell invasion and systemic spreading of Mycoplasma agalactiae in the sheep infection model. International Journal of Medical Microbiology 304 (8) 1024-1031



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Falzon, LC, O’Neill, TJ, Menzies, PI, Peregrine, AS, Jones-Bitton, A, Van Leeuwen, J, Mederos, A. (2014) A systematic review and meta-analysis of factors associated with anthelmintic resistance in sheep. Preventive Veterinary Medicine 117 (2) 388-402 Toet, H, Piedrafita, DM, Spithill, TW. 2014 Liver fluke vaccines in ruminants: strategies, progress and future opportunities. Int J Parasitol. 44(12):915-927. Mederos, A, Kelton, D, Peregrine, AS, Vanleeuwen, J, Fernandez, S, Leboeuf, A, Menzies, P, Martin, R. (2014) Evaluation of the utility of subjective clinical parameters for estimating fecal egg counts and packed cell volume in Canadian sheep flocks. Veterinary Parasitology 205 (3-4) 568-574 Andronicos, NM, Henshall, JM, Le Jambre, LF, Hunt, PW, Ingham, AB. (2014) A one shot blood phenotype can identify sheep that resist Haemonchus contortus challenge. Veterinary Parasitology 205 (3-4) 595-605 Vink, WD, McIntyre, LH. (2014) Active surveillance for scrapie in New Zealand: towards lymphoid tissue-based testing. New Zealand Veterinary Journal 62 (6) 361-362 Cornelius, MP, Jacobson, C, Besier, RB. (2014) Body condition score as a selection tool for targeted selective treatment-based nematode control strategies in Merino ewes. Veterinary Parasitology 206 (3-4) 173-181 Brown, C, Orford, M, Tzamaloukas, O, Mavrogenis, AP, Miltiadou, D. (2014) Assessment of inbreeding resulting from selection for scrapie resistance: a model for rare sheep breeds. Veterinary Record 175 (24) 624

http://www.ncbi.nlm.nih.gov/pubmed/25200351

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