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Detailed neuropathological findings in 222 cases of naturally occurring scrapie from Great Britain are described. The material consisted of formalin-fixed brain from eight breeds of sheep submitted between 1982 and 1991. Paraffin-embedded histological sections were made from several specified brain areas, including the medulla oblongata, cerebellum, pons, mesencephalon, diencephalon, septal area, basal ganglia and frontal cortex. Sections were examined by conventional and polarised light microscopy and the type and distribution of the lesions were recorded. Histologically, the lesions included vacuolation of neuronal perikarya and grey matter neuropil, neuronal degeneration (especially "dark' neurons) and loss, a reactive glial (predominantly astrocytic) response and amyloidosis. Vacuolar lesions were present in the cerebral cortex of 37 per cent of cases, centred around the superior frontal gyrus. Vacuolar lesions were detected in the neocortex for as long as sections have been taken from the superior frontal gyrus and are thus probably not a new feature of the disease. The distribution of vacuolation in the grey matter neuropil could be classified into seven patterns. Data from individual breeds of sheep showed that in some breeds there were significant differences in the age at which animals with different patterns of vacuolation died from scrapie.

The occurrence of bovine spongiform encephalopathy (BSE), recognition that it is a new scrapie-like disease epidemic in domestic cattle in the United Kingdom and concern of a remote zoonotic potential has, in four years, produced a plethora of documented information. While much of this information has been communicated outwith the scientific literature, this review attempts to summarise, from a neuropathological viewpoint, the main findings to emerge. The initial studies established the nosological homology of BSE with the subacute spongiform encephalopathies or "prion" diseases of animals and man. Epidemiological data are consistent with an extended common source epidemic originating from an abrupt change, commencing in 1981-82, in the exposure of domestic cattle to a scrapie-like agent in meat and bone meal incorporated into commercial animal feedstuffs. It is currently proposed that the method of production of meat and bone meal has contributed vital factors to the change in exposure. Invariability of the distribution pattern of vacuolar pathology in the natural disease and on primary transmission to cattle suggests a uniformity of the pathogenesis of BSE. Studies in mice suggest uniformity also of the biological properties of different BSE isolates but indicate that the properties differ from those of sheep scrapie isolates. Human health risks, although perceived to be negligible, have been addressed by various strategies including statutory measures and long term monitoring.

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Four of 17 cirl buntings (Emberiza cirlus) involved in a trial translocation in 2004 for conservation purposes died and were examined postmortem. Two of the cirl buntings showed intestinal and hepatic lesions, including necrotising enteritis, consistent with isosporoid coccidiosis, and a third had an intestinal infestation of isosporoid coccidia. Sporulated oocysts from faecal samples from the birds were identified as Isospora normanlevinei, a parasite previously detected in cirl bunting populations in continental Europe. In a subsequent translocation of 75 cirl buntings from Devon to Cornwall in 2006, each brood of birds was placed in strict quarantine at low stocking density, with improved hygienic precautions and detailed health surveillance, and each bird was treated prophylactically with toltrazuril in an attempt to control the disease but not eliminate the I normanlevinei parasites. Seventy-two of the 75 birds were successfully reared and released, and there were no apparent clinical or pathological signs of isosporoid coccidiosis in any bird. I normanlevinei was detected in the released population, an indication that it had been successfully conserved.

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Running Head: Disease risk analysis for a reintroduction programme 2 SummaryThere are risks from disease in undertaking wild animal reintroduction programmes. Methods of disease risk analysis have been advocated to assess and mitigate these risks,and, post-release health and disease surveillance can be used to assess the effectiveness of the disease risk analysis but results for a reintroduction programme have not to date been recorded. We carried out a disease risk analysis for the reintroduction of pool frogs (Pelophylax lessonae) to England, using information gained from the literature and from diagnostic testing of Swedish pool frogs and native amphibians. Ranavirus and Batrachochytrium dendrobatidis were considered high risk disease threats for pool frogs at the destination site. Quarantine was used to manage risks from disease due to these two agents at the reintroduction site: the quarantine barrier surrounded the reintroduced pool frogs. Post-release health surveillance was carried out through regular health examinations of amphibians in the field at the reintroduction site and collection and examination of dead amphibians. No significant health or disease problems were detected but the detection rate of dead amphibians was very low. Methods to detect a higher proportion of dead reintroduced animals and closely related species are required to better assess the effects of reintroduction on health and disease.

Background Since 2013, badger culling has been part of the UK Government's strategy for controlling bovine tuberculosis (bTB) within a high‐risk area (HRA) in England. Government surveillance data now enables an examination of bTB herd incidence and prevalence, its headline indicators, within and outside cull areas over the period 2009–2020. Methods Analysis compared herd incidence and prevalence data from within and outside badger culling areas. A range of models (GLMs, GLMMs, GAMs and GAMMs) were used to analyse incidence and prevalence in culled and unculled areas using frequentist and Bayesian approaches. Change in incidence across ten county areas within the HRA for the period 2010–2020 was also compared. Results Analyses based on Defra published data using a variety of statistical methodologies did not suggest that badger culling affected herd bTB incidence or prevalence over the study period. In 9 of 10 counties, bTB incidence peaked and began to fall before badger culling commenced. Limitations There are limitations around the data available on culling location, temporal information and other confounding factors. As such, further analysis of any future datasets that may be released on bTB levels in areas where badger culling has been implemented is warranted. Conclusion This examination of government data obtained over a wide area and a long time period failed to identify a meaningful effect of badger culling on bTB in English cattle herds. These findings may have implications for the use of badger culling in current and future bTB control policy.