Molecular surveillance of potential SARS-CoV-2 reservoir hosts in wildlife rehabilitation centers.

BACKGROUND: The COVID-19 pandemic, caused by SARS-CoV-2 infection, has become the most devastating zoonotic event in recent times, with negative impacts on both human and animal welfare as well as on the global economy. Although SARS-CoV-2 is considered a human virus, it likely emerged from animals, and it can infect both domestic and wild animals. This constitutes a risk for human and animal health including wildlife with evidence of SARS-CoV-2 horizontal transmission back and forth between humans and wild animals. AIM: Molecular surveillance in different wildlife rehabilitation centers and wildlife associated institutions in Chile, which are critical points of animal-human interaction and wildlife conservation, especially since the aim of wildlife rehabilitation centers is to reintroduce animals to their original habitat. MATERIALS AND METHODS: The survey was conducted in six WRCs and three wildlife associated institutions. A total of 185 samples were obtained from 83 individuals belonging to 15 different species, including vulnerable and endangered species. Each specimen was sampled with two different swabs: one oropharyngeal or nasopharyngeal according to the nostril diameter, and/or a second rectal sample. RNA was extracted from the samples and two different molecular assays were performed: first, a conventional RT-PCR with pan-coronavirus primers and a second SARS-CoV-2 qPCR targeting the N and S genes. RESULTS: All 185 samples were negative for SARS-CoV-2. CLINICAL RELEVANCE: This study constitutes the first report on the surveillance of SARS-CoV-2 from wildlife treated in rehabilitation centers in Chile, and supports the biosafety procedures adopted in those centers.

When free-ranging dogs threaten wildlife: Public attitudes toward management strategies in southern Chile.

Free-ranging dogs (Canis familiaris) significantly threaten wildlife, including endangered species. Although this problem resembles threats from other invasive animals, managing roaming dogs is even more fraught due to their close association with humans. Here we use interviews (n = 166) to document patterns of dog ownership and care and to measure public attitudes toward management strategies to control free-roaming dogs that threaten wildlife in rural areas of southern Chile. We compare attitudes toward lethal control and fines in scenarios where dogs attack livestock, children or wild animals or enter protected areas. We also test for variation in attitudes according to gender, age, education and proximity to urban areas. Most respondents (98.1%) opposed lethal control for at least one scenario and they were more likely to accept killing dogs that attacked sheep than those attacking wildlife. Similarly, support for fines was higher when dogs attacked livestock or people versus wild animals. Respondents consistently favored fining the owner over eliminating the problem dog. When asked about their management preferences, many respondents indicated that the movement of problem dogs-including to a lesser extent those threatening wildlife-should be restricted. However, in practice most dog-owners allowed one or more of their dogs to move freely at least part of the time. Finally, the wildlife species of concern mattered, e.g. 40% thought no action was necessary when dogs attack foxes, but this dropped to 12% for pudu (a small deer). In sum, participants had significantly more concern for livestock and human safety than for wildlife protection. We close by discussing management and policy implications.

Urban dogs in rural areas: Human-mediated movement defines dog populations in southern Chile.

Management strategies for dog populations and their diseases include reproductive control, euthanasia and vaccination, among others. However, the effectiveness of these strategies can be severely affected by human-mediated dog movement. If immigration is important, then the location of origin of dogs imported by humans will be fundamental to define the spatial scales over which population management and research should apply. In this context, the main objective of our study was to determine the spatial extent of dog demographic processes in rural areas and the proportion of dogs that could be labeled as immigrants at multiple spatial scales. To address our objective we conducted surveys in households located in a rural landscape in southern Chile. Interviews allowed us to obtain information on the demographic characteristics of dogs in these rural settings, human influence on dog mortality and births, the localities of origin of dogs living in rural areas, and the spatial extent of human-mediated dog movement. We found that most rural dogs (64.1%) were either urban dogs that had been brought to rural areas (40.0%), or adopted dogs that had been previously abandoned in rural roads (24.1%). Some dogs were brought from areas located as far as ∼700km away from the study area. Human-mediated movement of dogs, especially from urban areas, seems to play a fundamental role in the population dynamics of dogs in rural areas. Consequently, local scale efforts to manage dog populations or their diseases are unlikely to succeed if implemented in isolation, simply because dogs can be brought from surrounding urban areas or even distant locations. We suggest that efforts to manage or study dog populations and related diseases should be implemented using a multi-scale approach.

Invasive American mink: linking pathogen risk between domestic and endangered carnivores.

Infectious diseases, in particular canine distemper virus (CDV), are an important threat to the viability of wild carnivore populations. CDV is thought to be transmitted by direct contact between individuals; therefore, the study of species interactions plays a pivotal role in understanding CDV transmission dynamics. However, CDV often appears to move between populations that are ecologically isolated, possibly through bridge hosts that interact with both species. This study investigated how an introduced species could alter multihost interactions and act as a bridge host in a novel carnivore assemblage of domestic dogs (Canis familiaris), invasive American mink (Neovison vison), and threatened river otters (Lontra provocax) in southern Chile. We found that rural dogs interact with mink near farms whereas in riparian habitats, minks and river otters shared the same latrines with both species visiting sites frequently within time intervals well within CDV environmental persistence. No interactions were observed between dogs and otters at either location. Both dog and mink populations were serologically positive for CDV, making the pathogen transfer risk to otters a conservation concern. Altogether, introduced mink in this ecosystem have the potential to act as bridge hosts between domestic dogs and endangered carnivores.

Domestic dogs in rural communities around protected areas: conservation problem or conflict solution?

Although domestic dogs play many important roles in rural households, they can also be an important threat to the conservation of wild vertebrates due to predation, competition and transmission of infectious diseases. An increasing number of studies have addressed the impact of dogs on wildlife but have tended to ignore the motivations and attitudes of the humans who keep these dogs and how the function of dogs might influence dog-wildlife interactions. To determine whether the function of domestic dogs in rural communities influences their interactions with wildlife, we conducted surveys in rural areas surrounding protected lands in the Valdivian Temperate Forests of Chile. Sixty percent of farm animal owners reported the use of dogs as one of the primary means of protecting livestock from predators. The probability of dog-wild carnivore interactions was significantly associated with the raising of poultry. In contrast, dog-wild prey interactions were not associated with livestock presence but had a significant association with poor quality diet as observed in previous studies. Dog owners reported that they actively encouraged the dogs to chase off predators, accounting for 25-75% of the dog-wild carnivore interactions observed, depending on the predator species. Humans controlled the dog population by killing pups and unwanted individuals resulting in few additions to the dog population through breeding; the importation of predominantly male dogs from urban areas resulted in a sex ratios highly dominated by males. These results indicate that dog interactions with wildlife are related to the role of the dog in the household and are directly influenced by their owners. To avoid conflict with local communities in conservation areas, it is important to develop strategies for managing dogs that balance conservation needs with the roles that dogs play in these rural households.