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Disease Issues Associated with Captive and Trade-Confiscated Viverrids in Northern Vietnam
The increasing demand for wildlife drives an illegal trade which threatens the conservation of biodiversity in Southeast Asia (Bennet, Milner-Gulland et al., 2002; Roberton, 2007). Consumption of wild meat in specialized restaurants and utilization of wildlife products as tonics and remedies in traditional medicine are practices which appear to be growing in popularity (Venkataraman, 2007). As Asian wildlife populations decline in the face of increased hunting pressure, traders have been forced to source animals from an ever widening geographic range (Bennet, Milner-Gulland et al., 2002; Venkataraman, 2007; Van Song, 2008). As a result birds, mammals and reptiles are currently shipped in massive quantities from countries all over Asia, to markets all over the globe (WWF/TRAFFIC, 2002; Nijman, 2009). In addition to the conservation impact of this trade, the potential consequences of this practice for both human and animal health are great. The enormous volume of the trade, and mixture of species transported globally in poor conditions, provides opportunities for direct contact between wildlife, domestic animals and humans, and the pathogens they carry. As a result, this trade is increasingly recognised as an important mechanism for the geographic spread and emergence of infectious diseases (Deem, Karesh et al., 2001; Bell, Roberton et al., 2004; Karesh, Cook et al., 2007; Jones, Pattel et al., 2008). It is widely believed that animals in the illegal wildlife trade are in poor and deteriorating health (Leighton, 2002; Bell, Roberton et al., 2004; Karesh, Cook et al., 2007), and the potential impact for human health became apparent in 2002, when Severe Acute Respiratory Syndrome coronavirus (SARS CoV) emerged from the wildlife markets of Southern China (Guan, Zheng et al., 2003). However, an additional, and rarely considered, consequence of the growing trade in wildlife is the increasing number of mentally and physically sick and injured wild animals which are confiscated and transferred to rescue centres in the region, many of which lack the resources to adequately care for the animals they receive (Karesh, 1995; Duy, Hoang et al., 2010). In July 2008, a veterinarian, the author, arrived at the Carnivore and Pangolin Conservation Program (CPCP), a rescue centre for small carnivores and pangolins confiscated from the illegal wildlife trade and a conservation breeding centre for the Owston’s civet (Chrotogale owstoni), in Cuc Phuong National Park, Vietnam. The aim was to begin to build basic veterinary skills and understanding within the centre in an attempt to improve their capacity to adequately manage the health of the animals transferred to their care. Less than two months later, the first two cases of Civet Neurological and Respiratory Syndrome (CNRS) (Chapter 3, Section 3.3.4) presented, followed very quickly by the second two cases of this novel clinical syndrome. The ensuing challenges faced in efforts to properly investigate the underlying aetiology of this fatal presentation marked the beginnings of the research which would eventually lead to this thesis. Chapter one of this work provides a review of the literature on the illegal wildlife trade in Asia, and its links to the spread and emergence of infectious diseases. This chapter also introduces the reader to the family Viverridae, a family of small, nocturnal carnivores which includes civets, linsangs and binturong, describes the current and historical exploitation of viverrids for human consumption, and explains why further research on the health status of members of this family is overdue. The Second chapter then presents the first attempt to collate information about all currently recognised pathogens of the Viverridae, following an exhaustive review of the literature, and collation of the many disparate sources of information to create a baseline of existing knowledge for this family. Understanding the diseases that have previously, and commonly, been observed in a certain species assists in the development of appropriate husbandry and preventive medicine protocols, enables a more thorough appreciation of the risk to both human and animal health associated with direct contact with this species (Travis, Hungerford et al., 2006) and can provide an indication of the importance of infectious disease in the conservation of the species (Leendertz, Pauli et al., 2006). This information can also help to guide future surveillance programs or disease outbreak investigations towards expected pathogens. Chapter Three represents the first attempt to investigate the health of trade confiscated and captive Viverridae in Vietnam by reviewing medical records for all viverrids transferred to, or born in, the CPCP, Cuc Phuong National Park, Ninh Binh Province, Vietnam, between 1995 and 2009. Given the lack of official information on the health of trade confiscated wildlife in Vietnam (Ha, Dung et al., 2007), animal medical records kept by wildlife rescue centres in the country may provide an important alternative source of information. Rescue centre records represent an invaluable source of information from which the general health status of animals within the illegal wildlife trade can be extrapolated, and can provide longitudinal information on the common clinical signs and syndromes associated with morbidity and mortality in a population of rescued, rehabilitated wildlife (Warren, 2001; Duncan, Backus et al., 2008; Trocini, Pacioni et al., 2008). This data can help to inform future monitoring events and targeted surveillance (Lonsdorf, Travis et al., 2006). Baseline health monitoring parameters, such as blood biochemistry and haematology reference ranges specific to the species in question, are useful tools for objective monitoring of the general health status of both captive and free ranging wildlife (Vié, Moreau et al., 1998; Maklon, Boonyarittichaikij et al., 2006; Tryland, 2006). However, in spite of the accepted usefulness of these reference ranges, baseline health parameters such as these do not currently exist for many species of wildlife, including many of the viverrids (Davis, Maney et al., 2008). Chapter 4 presents the first attempt to develop serum biochemistry and haematology reference ranges for one species of viverrid in Vietnam, the Owston’s civet. It is hoped that this thesis will provide a founding contribution to our understanding of the health status of trade confiscated viverrids in Vietnam. Identifying the commonly seen clinical signs and syndromes associated with mortality and morbidity in confiscated and captive born wildlife, and the creation of baseline physiological data for a commonly traded species, will provide information which can help to guide the development of human and material resources in rescue centres and veterinary services in the region to better manage this population of animals.