Wildlife Disease and Zoonotics


Date of this Version

December 2000


Published jointly by the IUCN Species Survival Commission’s Veterinary Specialist Group, Gland, Switzerland, the Office International des Epizooties (OIE), Paris, France, Care for the Wild, U.K., and the European Association of Zoo and Wildlife Veterinarians, Switzerland.


In recent years the translocation and release into the wild of wild-caught and captive-bred wild animals (mammals, birds, reptiles, amphibians and fish) has become a common practice, ostensibly for rehabilitation or conservation purposes. These wild animals comprise many varied taxa and the objectives of translocation and release may include:
(1) reintroducing a species that has become extinct in its natural range;
(2) restocking or reinforcing a population which has become depleted; and
(3) rehabilitating wild animals and birds which have been illegally captured and subsequently confiscated by Customs or national wildlife authorities. Welfare organizations also receive sick and injured wild animals from the public and some of these can be restored to health and released.
Each year very large numbers of wild animals also undergo both local and transcontinental translocation for release in new and strange habitats for sporting purposes. For example, hares (Lepus europaeus) are regularly translocated from Argentina to France and from Eastern Europe to Italy.
It is now widely recognized by wildlife veterinarians that every wild creature that is the subject of a translocation or rehabilitation release must not be regarded as just a single animal but rather as a “package” containing an assortment of potentially dangerous viruses, bacteria, protozoa, helminths and arthropods, any of which may become pathogenic in a new situation, involving stressed individuals in a changed environment.
Translocation of an animal and its potential pathogens, over even a short distance, may threaten the health of indigenous wild species, domestic livestock or humans. In addition, the effects of stress on the immune system of animals while held in captivity pending translocation and release may increase this risk, unless well managed. However, the risk can be assessed in advance and substantially reduced if timely veterinary precautions are taken.
These precautions will include: a clinical evaluation of the health status of the source animals and those at the translocation destination, a period of quarantine, appropriate health screening procedures, a consideration of the legal and veterinary restrictions on translocation of wild animals to and from certain geographic areas or populations, and when necessary, pre-release treatment and immunization. It should be remembered that not only should the translocated animals undergo health screening but so also should the indigenous wildlife in the reception area.