LAUSR

This report is produced each month by the APHA Surveillance Intelligence Unit and the six Species Expert Groups (livestock and wildlife). The international horizon-scanning summaries are produced by the Defra/APHA International Disease Monitoring (IDM) team, notifiable disease reports by the APHA Veterinary Exotic and Notifiable Disease Unit (VENDU), and threat analysis by the cross-agency Veterinary Risk Group (VRG). The report is drawn from scanning surveillance information, data and reports produced by the APHA Veterinary Investigation Centres and non-APHA partner postmortem examination providers contributing to the VIDA database and complying with standardised diagnostic and laboratory testing criteria. Other livestock and wildlife scanning surveillance reports may also be found at www.gov.uk/government/collections/animaldisease-surveillance-reports Current and emerging issues Schmallenberg update Schmallenberg virus (SBV) was first identified in Europe in 2011, and the disease has since spread throughout Europe to Finland in the north, Spain in the south and Turkey in the east. SBV was identified in Great Britain during 2012, principally in England, but also in the Welsh borders. Recrudescence of congenital disease was seen in October 2016 and continued through the calving and lambing seasons in 2017 (http:// ahvla.defra.gov.uk/vet-gateway/ schmallenberg/index.htm), affecting a larger area than previously. This included wider areas of Wales, the north of England and the Scottish borders. This recrudescence and expansion of geographical range was likely due to a combination of factors. These include favourable weather conditions allowing spread via competent vector midges of the Culicoides genus into previously uninfected areas and, in the endemic areas, a decline in herd and flock immunity due to increasing numbers of naive replacement animals and low levels of vaccine uptake. Focused serological surveys undertaken in Scotland through bulk milk surveillance, and in sheep, principally in England, suggest that immunity to SBV is more widespread. A vaccine is available that confers immunity to SBV in cattle and sheep, and which in sheep has a licence variation for a single-dose primary course. It is a matter for discussion between farmers and their private veterinarians as to the relative advantages of using the vaccine in their herds and flocks. Vets and farmers should be aware that stocks of vaccine are very limited, and are short-dated (towards the end of July 2018). Highlights from the scanning surveillance network Cattle Abortions associated with Neospora caninum infection (Fig 1) were recorded by several Veterinary Investigation Centres (VICs). Most were sporadic losses, but one case investigated by the APHA Shrewsbury VIC involved the examination of four aborted calves, submitted separately over an 11-day period. They were from one dairy herd of 140 cows, where a total of eight abortions had occurred over a two-week period. No specific gross pathology was identified, but N caninum DNA was detected by PCR in the brains of all four of the submitted calves. Histopathology indicated a non-suppurative encephalitis and myocarditis, confirming neosporosis as the cause of the abortions. The reason for this series of abortions or ‘mini-storm’ is uncertain (the term ‘abortion storm’ usually refers to outbreaks where 10 per cent or more of an at-risk group of cows aborts over a period of six weeks). It is generally accepted that the majority of cows become infected by N caninum endogenously from their dams. However, when such ‘ministorm’ outbreaks occur there is the possibility of an exogenous canine source of infection, with the cows becoming infected through ingestion of N caninum oocysts. Epidemiological evidence has suggested that the introduction of a dog to a farm within 18 months before the abortions commencing Vets and farmers should be aware that stocks of SBV vaccine are very limited, and are shortdated