VETERINARY ASPECTS OF EX SITU BREEDING FOR CONSERVATION TRANSLOCATIONS
Many populations of threatened and endangered native mammals persist in small numbers, often in highly fragmented habitats with a restricted geographical range and persistent threatening processes.
Captive breeding offers the potential for propagating sufficient numbers of animals for CT under controlled conditions and as such, individuals bred in managed care constitute the source population for an increasing number of CT programs. Ex situ-breeding programs offer a unique opportunity to establish baseline health and disease data, as well as veterinary expertise for a given species that can then be applied to the conservation management of both managed and free-ranging populations and in the planning for and implementation of CTs. Examples of managed populations contributing to the establishment of baseline health data include haematology and biochemistry parameters for western quolls (D. geoffroii) (Svensson et al. 1998), haematology parameters for western barred bandicoots (P. bougainville) (Bennett et al. 2007), haematology and biochemistry reference intervals for greater bilbies (Macrotis lagotis) (Warren et al. 2015), haematology and biochemistry reference intervals for brush-tailed rock-wallabies (Petrogale penicillata) (Schultz et al. 2011) and haematology and biochemistry reference intervals for Tasmanian devils (Stannard et al. 2016).Pathogens and parasites that occur in free-ranging individuals and populations with minimal health impacts may have more serious consequences while in managed care where higher stocking densities, suboptimal nutrition, exposure to novel pathogens, anthropogenic stressors and other husbandry-related factors alter the host-pathogen relationship (Breed et al. 2009). Examples of diseases associated with altered host-pathogen relationships in managed care include severe granulomatous gastritis in zoo-housed eastern barred bandicoots associated with the spirurid nematode Physalaptera peramelis (Seebeck and Booth 1996), progressive periodontal disease in macropods and greater bilbies (Lynch 2008; Vogelnest and Portas 2008) and cutaneous mycobacteriosis in zoohoused quolls and Tasmanian devils (see Chapters 12 and 22).
Additionally, native mammals may acquire pathogens and parasites in managed care that may not be associated with clinical signs but may constitute a risk to the individual, conspecifics or sympatric species following release to the wild. Examples include Bacillus cereus in dibblers (Parantechinus apicalis) (Mathews et al. 2006) and Cryptosporidium muris in greater bilbies (Warren et al. 2003).Preventative health programs and biosecurity, therefore, are important components of ex situ-breeding programs. Detailed recommendations for preventative health programs are beyond the scope of this chapter. Specific preventative health considerations in captivebreeding programs for CTs include management of codependent parasites (section 5.2), maintenance of immunity against specific diseases that may be encountered post release and prevention of exposure to nonnative pathogens and parasites.
3.