We have a long-standing programme of disease surveillance in Scottish red squirrels, which has led to a number of more-focused research projects and associated publications on the epidemiology and diagnosis of diseases of squirrels.
R(D)SVS red squirrel disease surveillance scheme
Professor Elspeth Milne and colleagues in the R(D)SVS Pathology Unit run a long-standing programme of disease surveillance in Scottish red squirrels. Post mortem examinations are conducted on red squirrel carcasses submitted from across Scotland by members of the public, veterinary practices and wildlife rangers with help with coordination from the Scottish Wildlife Trust. This programme has led to a number of more-focused research projects and associated publications on the epidemiology and diagnosis of diseases of squirrels, in particular squirrelpox virus, squirrel adenovirus-1, leprosy (see below) and atypical histiocytosis. The group has extensive collaborations with others involved in squirrel research including Nottingham Trent University, the University of Glasgow, APHA and the Friedrich-Loeffler-Institut in Germany, in order to maximise use of the submitted material.
The squirrel leprosy project started with some unusual cases submitted to the R(D)SVS red squirrel surveillance scheme.
Six index cases of Scottish red squirrels with unusual skin changes arrived between 2006 and 2013. Mycobacterium lepromatosis, one of the two bacteria causing leprosy was identified in these animals (Meredith et al. 2014) and further research by our group was able to show that leprosy occurs in Eurasian red squirrels throughout the British Isles. The second bacterium causing leprosy, Mycobacterium leprae, can be found in squirrels as well. Both bacteria can cause clinical disease in squirrels or be carried without obvious signs of disease and are related to bacterial strains that historically caused disease in humans (Avanzi et al. 2016).
A recently completed PhD research project focussed on assessing affected squirrel populations over time, to better understand the disease processes and impact on the populations. Additionally, the different stages of disease in individual animals were characterised. The results of this research are still in the process of being fully published through peer reviewed journal, but a summary of the information now available about squirrel leprosy can be downloaded here. Its aim is to provide brief, accessible information to those working with red squirrels in conservation and wildlife rescue settings. The information is available in English, German and French (translation kindly provided by Dr. Charlotte Avanzi).
The project is supported by The National Trust, The Dorset Wildlife Trust, The National Trust Scotland and The Forestry Commission Scotland. Collaborations include individuals from Moredun Research Institute, Leiden University Medical Centre, Ecole polytechnique federale de Lausanne, The Friedrich Loeffler Institute, SRUC, The University of Milan, Bangor University, The Scottish Wildlife Trust, Wildtierhilfe Odenwald e.V., as well as private individuals submitting carcasses and images for assessment.
Funding was provided by the Principals Career Development Scholarship, University of Edinburgh and the Scottish Government.
For further information, please contact Anna Schilling.