This chaper briefly discusses a range of infections not usually found in the UK and, hence, referred to as exotic. The geographic distribution of these infections may be limited for two main reasons. Firstly, transmission of infection may depend on specific arthropod vectors that occur only outside the UK. Secondly, concerted disease control efforts may have led to eradication of disease in the UK. However, resurgence of such diseases in the UK might be expected more frequently as a result of increased movement of people and animals, expansion of the European Union, where disease security is dependent on its weakest point, and the consequences of global warming.
Specific scientific information is lacking for many infections that affect donkeys. Therefore, relevant information on diseases as they manifest in the horse has occasionally been included in this chapter. Diseases are discussed in outline only, with an emphasis on the factors relevant to donkeys. This chapter should, therefore, be read in conjunction with standard texts describing the diseases and their diagnosis and treatment in more detail.
Although the donkey shares a common ancestor with the horse (the Hyracotherium or the Dawn Horse), the evolution of these two species diverged approximately four million years ago. They then adapted to different environments and disease challenges, which may explain the different epidemiology observed with some infections.