Beaver Borne Diseases and Quarantine
Three independent studies commissioned by the statutory nature conservation bodies for Scotland, England and Wales have all examined the potential for disease transmission from reintroduced beaver populations. All have concluded that there is no significant risk if basic health screening is undertaken in quarantine. The recent identification of the parasiteEchinococcus multilocularis in an imported beaver in captivity in Devon does illustrate that there is potential for other conditions to arise. This disease is not known to exist in Britain and is transmitted by infected carnivores to other host species which cannot transmit the disease until they die and are consumed by a predator. Dogs and foxes are the most common agents of dispersal. Any captive bred beavers currently in the UK will therefore be clear of the condition and there are range states within Europe where it does not currently exist.
In the event that captive bred beavers were not available and that further imports are required the law states that any beavers entering the British Isles which are wild caught as opposed to captive bred must undergo a 6 month quarantine period for rabies. It is to be expected from experience that the mortality of any imported or reintroduced population will be high and therefore provision should be made to support any initial release with further individuals as required. This could entail ensuring that more animals are imported than are required, that back up populations are established in participating zoos for future use and that consideration is given to the establishment of an enclosed but free living reserve of animals elsewhere on a project site. This last measure would enable the rapid transferral of any required replacements into vacant territories as appropriate.
The Royal Zoological Society of Scotland have developed a comprehensive health screening process for beavers and are now well positioned to advise on any arising issues. Their husbandry guideline provides in depth detail regarding this subject.