Potential transmision of dog pathogens to wild carnivores in India

Chaudhary, V. (2016). Threats of Disease Spillover from Domestic Dogs to Wild Carnivores in the Kanha Tiger Reserve, India. MSc disertation  Graduate School of Clemson University.

Many mammalian carnivore species persist in small, isolated populations as a result of habitat destruction, fragmentation, poaching, and human conflict. Their small numbers, limited genetic variability, and increased exposure to domestic animals such as dogs place them at risk of further losses due to infectious diseases. In India, dogs ranging from domestic to feral are associated with villages in and around protected areas, and may serve as reservoirs and vectors of pathogens to the carnivores within. India’s Kanha Tiger Reserve (KTR) is home to a number of threatened and endangered mammalian carnivores including tigers (Panthera tigris), leopards (Panthera pardus), wolves (Canis lupus), and dhole (Cuon alpinus). It also contains hundreds of small villages with associated dog populations, and my goal was to determine whether these dogs pose a disease threat to KTR’s wild carnivores. In the summer of 2014 and again in the winter of 2015 I estimated the density of dogs in villages of varying sizes and distances from KTR’s core zone, and the exposure of these dogs to four pathogens that could threaten wild carnivores: rabies, canine parvovirus (CPV), canine distemper (CDV), and canine adenovirus (CAV). Dog population densities ranged from 3.7 to 23.7/km²(14 to 45 dogs/village), and showed no systematic variation with village area or human population size. These dog populations grew in all villages between the summer of 2014 and winter of 2015, primarily through reproduction. No dog tested positive for rabies but I found high levels of seroprevalence to the other three pathogens: CPV (83.6% in summer 2014,
68.4% in winter 2015), CDV (50.7% in summer 2014, 30.4% in winter 2015) and CAV (41.8% in summer 2014, 30.9% in winter 2015). The declines in seroprevalence between summer and winter were primarily due to births in the population, of animals not exposed to the viruses. I opportunistically documented interactions between the dogs and wild carnivores that might allow disease transmission. I measured these interactions as the presence of wild carnivores in surveyed villages. In this study I document the existence of a large population of unvaccinated dogs in and around KTR, with high levels of seroprevalence to pathogens with broad host ranges. These dogs also have frequent contact with wild carnivores. I conclude that these dogs pose a high risk of disease spillover to wild carnivores in the region.
I also tested for CPV and CDV in wild carnivore samples obtained from the KTR Forest Department from 2010 to 2015. While one tiger blood sample was seropositive for CPV antibodies, the reverse transcriptase polymerase chain reaction found no evidence of CPV in tissue samples from five tigers, one leopard and one palm civet (Paradoxurus hermaphroditus), and no CPV or CDV in the three blood samples of tigers. Despite these results, I argue for continued surveillance in KTR, given the ubiquity of village dogs in the area with high seroprevalence of CDV and CPV and the contact between dogs and endangered carnivores in KTR. 

Fatal canine distemper infection in a pack of African wild dogs in the Serengeti

Goller, K. V., Fyumagwa, R. D., Nikolin, V., East, M. L., Kilewo, M., Speck, S., ... & Wibbelt, G. (2010). Fatal canine distemper infection in a pack of African wild dogs in the Serengeti ecosystem, Tanzania. Veterinary microbiology, 146(3), 245-252.

In 2007, disease related mortality occurred in one African wild dog (Lycaon pictus) pack close to the north-eastern boundary of the Serengeti National Park, Tanzania. Histopathological examination of tissues from six animals revealed that the main pathologic changes comprised interstitial pneumonia and suppurative to necrotizing bronchopneumonia. Respiratory epithelial cells contained numerous eosinophilic intracytoplasmic inclusion bodies and multiple syncytial cells were found throughout the parenchymal tissue, both reacting clearly positive with antibodies against canine distemper virus (CDV) antigen. Phylogenetic analysis based on a 388 nucleotide (nt) fragment of the CDV phosphoprotein (P) gene revealed that the pack was infected with a CDV variant most closely related to Tanzanian variants, including those obtained in 1994 during a CDV epidemic in the Serengeti National Park and from captive African wild dogs in the Mkomazi Game Reserve in 2000. Phylogenetic analysis of a 335-nt fragment of the fusion (F) gene confirmed that the pack in 2007 was infected with a variant most closely related to one variant from 1994 during the epidemic in the Serengeti National Park from which a comparable fragment is available. Screening of tissue samples for concurrent infections revealed evidence of canine parvovirus, Streptococcus equi subsp. ruminatorum and Hepatozoon sp. No evidence of infection with Babesia sp. or rabies virus was found. Possible implications of concurrent infections are discussed. This is the first molecular characterisation of CDV in free-ranging African wild dogs and only the third confirmed case of fatal CDV infection in a free-ranging pack.

Pathogens of wild maned wolves in Brazil

Curi, N. H. D. A., Coelho, C. M., Malta, M. D. C. C., Magni, E. M. V., Sábato, M. A. L., Araújo, A. S., ... & Souza, S. L. P. D. (2012). Pathogens of wild maned wolves (Chrysocyon brachyurus) in Brazil. Journal of wildlife diseases, 48(4), 1052-1056.

The maned wolf, Chrysocyon brachyurus, is an endangered Neotropical canid that survives at low population densities. Diseases are a potential threat for its conservation but to date have been poorly studied. We performed clinical evaluations and investigated the presence of infectious diseases through serology and coprologic tests on maned wolves from Galheiro Natural Private Reserve, Perdizes City, Minas Gerais State, southeastern Brazil. Fifteen wolves were captured between 2003 and 2008. We found high prevalences of antibody to canine distemper virus (CDV; 13/14), canine
parvovirus (CPV; 4/14), canine adenovirus type 2 (13/14), canine coronavirus (5/11), canine parainfluenza virus (5/5), and Toxoplasma gondii (6/8), along with Ancylostomidae eggs in all feces
samples. Antibodies against Leishmania sp. were found in one of 10 maned wolves, and all samples were negative for Neospora caninum. Evidence of high exposure to these viral agents was also observed in unvaccinated domestic dogs from neighboring farms. High prevalence of viral agents and parasites such as CDV, CPV, and Ancylostomidae indicates that this population faces considerable risk of outbreaks and chronic debilitating parasites. This is the first report of exposure to canine parainfluenza virus in Neotropical free-ranging wild canids. Our findings highlight that canine pathogens pose a serious hazard to the viability of maned wolves and other wild carnivore populations in the area and emphasize the need for monitoring and protecting wildlife health in remaining fragments of the Cerrado biome.

Contact between wild and domestic canids and virus transmision

Courtenay, O., Quinnell, R. J., & Chalmers, W. S. K. (2001). Contact rates between wild and domestic canids: no evidence of parvovirus or canine distemper virus in crab-eating foxes. Veterinary Microbiology, 81(1), 9-19.


Evaluating the risk of disease spill-over from domestic dogs to wildlife depends on knowledge of inter-specific contact rates and/or exposure to aetiological agents in dog environments. Here, contact rates of crab-eating foxes (Cerdocyon thous) with sympatric domestic dog populations were measured over 25 months in Amazon Brazil. Foxes and dogs were serologically and clinically monitored for exposure to canine parvovirus (CPV-2) and canine distemper virus (CDV), pathogens known to have caused wildlife population declines elsewhere. Twenty-two of 24 (92%) tagged foxes visited one or more houses in a median 2 (range 1–3) villages per night where dog densities ranged from 7.2 to 15.4 per km² (mean 9.5 per km²). Foxes spent an average 6.4% (0–40.3%) of their 10 h nocturnal activity period in villages, the equivalent of 38 m (range 0–242) per night. The rate of potential exposure to disease agents was thus high, though varied by 3 orders of magnitude for individual foxes. Overall, 46% of the fox population was responsible for 80% of all contacts. None of the 37 monitored foxes however showed serological or clinical evidence of infection with CPV-2 or CDV. Seroprevalences for CPV-2 and CDV antibodies in the local domestic dog population were 13% (3/23) and 9% (2/23), respectively, and 89% of 97 monitored pups born during the study presented clinical signs consistent with active CPV-2 infection (haemorrhagic diarrhoea, vomiting, rapid morbidity and emaciation). Although there was no evidence for infection with either virus in foxes, the high level of contact of foxes with peridomestic habitats suggests that the probability of potential spill-over infections from dogs to foxes is high.

Exposure of free-ranging maned wolves to infectious and parasitic disease agents

Deem, S. L., & Emmons, L. H. (2005). Exposure of free-ranging maned wolves (Chrysocyon brachyurus) to infectious and parasitic disease agents in the Noel Kempff Mercado National Park, Bolivia. Journal of Zoo and Wildlife Medicine, 36(2), 192-197.

Maned wolves (Chrysocyon brachyurus) are neotropic mammals, listed as a CITES Appendix II species, with a distribution south of the Amazon forest from Bolivia, through northern Argentina and Paraguay and into eastern Brazil and northern Uruguay. Primary threats to the survival of free-ranging maned wolves include habitat loss, road kills, and shooting by farmers. An additional threat to the conservation of maned wolves is the risk of morbidity and mortality due to infectious and parasitic diseases. Captive maned wolves are susceptible to, and die from, common infectious diseases of domestic dogs (Canis familiaris) including canine distemper virus (CDV), canine parvovirus (CPV), rabies virus, and canine adenovirus (CAV). Results from this study show that free-ranging maned wolves in a remote area of Bolivia have been exposed to multiple infectious and parasitic agents of domestic carnivores, including CAV, CDV, CPV, canine coronavirus, rabies virus, Leptospira interrogans spp., Toxoplasma gondii, and Dirofilaria immitis, and may be at increased risk for disease due to these agents.

Dog diet and interaction with wildlife in Colombia

Manjarrés Rodríguez, T. S. (2015). Dieta del perro (Canis familiaris) y sus interacciones con la fauna silvestre de la cuenca alta del Río Otún-Risaralda (Colombia). Trabajo de grado presentado para optar al titulo de: Magister en Conservación y Uso de la Biodiversidad (Modalidad de investigación) 

The dog (Canis familiaris) interact with the wild life mainly through depredation, competition and disease transmission. However, it is not known very clearly how these interactions occur. To answer this question, this work identified the dog's diet and the presence of disease Parvovirus (CPV). From this information, contrasted with the knowledge of the residents of the study area, the possible interactions with the dog can keep wildlife in the study area were determined. The diet analysis showed that dog consumed waste, followed by the rest of medium and small mammals, and finally to a lesser extent vegetation and insects. The community also identified the consumption of birds and reptiles in a low percentage. Neither dog feces showed the presence of CPV, possibly in part because community mentioned that all domestic dogs were vaccinated. However the perception of the community on predation dog does not resemble reality obtained in this study, so it is recommended to do session about esterilizaton and vaccination, and to awareness the workers and community about dog control and prohibit the entry of those coming with tourists in the study area.

Dog diseases threat Ethiopian wolf

Laurenson, K., Sillero‐Zubiri, C., Thompson, H., Shiferaw, F., Thirgood, S., & Malcolm, J. (1998). Disease as a threat to endangered species: Ethiopian wolves, domestic dogs and canine pathogens. Animal Conservation, 1(4), 273-280.

With increasing awareness of disease as an endangering process, an assessment of which pathogens might pose a problem and their patterns of infection in natural hosts is necessary. This paper examines the exposure of sympatric Ethiopian wolves (Canis simensis) and domestic dogs to canine distemper virus (CDV), canine adenovirus (CAV) and canine parvovirus (CPV) in the Bale region, Ethiopia and then relates these data to population trends of wolves. Wolves (n= 30) sampled between 1989 and 1992 had been exposed to CDV, CAV and CPV, but only CAV might be able to persist in this wolf population. Anecdotal and serological evidence suggested that an epidemic of CDV occurred in the dog population of the Bale Mountains National Park (BMNP) in 1992–93. All park dogs born since this time were seronegative to CDV, although some young dogs in the nearby urban population were seropositive. Despite evidence of CAV infection in wolves, none of the dogs sampled in the park were CAV seropositive, although this virus appeared highly seroprevalent and endemic in urban dogs. All dogs tested for CPV antibodies were seropositive. The BMNP wolf population declined in the late 1980s and early 1990s, with rabies responsible for a dramatic population reduction between 1990 and 1992. Although the population declined further up until 1995, it is not possible to assess whether the concurrent canine distemper epidemic in park dogs also affected wolves. Nevertheless, with evidence of rabies, CDV, CAV and CPV infections in sympatric domestic dogs and Ethiopian wolves, canid diseases clearly pose a significant threat to the future persistence of this Ethiopian wolf population.

Dog disease threats for wild canid conservation in SE Brazil

de Almeida Curi, N. H., Araújo, A. S., Campos, F. S., Lobato, Z. I. P., Gennari, S. M., Marvulo, M. F. V., Ramos Silva, J.C. & Talamoni, S. A. (2010). Wild canids, domestic dogs and their pathogens in Southeast Brazil: disease threats for canid conservation. Biodiversity and Conservation, 19(12), 3513-3524.

Wild canids are under many pressures, including habitat loss, fragmentation and disease. The current lack of information on the status of wildlife health may hamper conservation efforts in Brazil. In this paper, we examined the prevalence of canine pathogens in 21 free-ranging wild canids, comprising 12 Cerdocyon thous (crab-eating fox), 7 Chrysocyon brachyurus (maned wolf), 2 Lycalopex vetulus (hoary fox), and 70 non-vaccinated domestic dogs from the Serra do Cipó National Park area, Southeast Brazil. For wild canids, seroprevalence of antibodies to canine parvovirus, canine adenovirus, canine coronavirus and Toxoplasma gondii was 100 (21/21), 33 (7/21), 5 (1/19) and 68 (13/19) percent, respectively. Antibodies against canine distemper virus, Neospora caninum or Babesia spp. were not found. We tested domestic dogs for antibodies to canine parvovirus, canine distemper virus and Babesia spp., and seroprevalences were 59 (41/70), 66 (46/70), and 42 (40/70) percent, respectively, with significantly higher prevalence in domestic dogs for CDV (P < 0.001) and Babesia spp. (P = 0.002), and in wild canids for CPV (P < 0.001). We report for the first time evidence of exposure to canine coronavirus in wild hoary foxes, and Platynossomun sp. infection in wild maned wolves. Maned wolves are more exposed to helminths than crab-eating foxes, with a higher prevalence of Trichuridae and Ancylostomidae in the area. The most common ectoparasites were Amblyomma cajennense, A. tigrinum, and Pulex irritans. Such data is useful information on infectious diseases of Brazilian wild canids, revealing pathogens as a threat to wild canids in the area. Control measures are discussed.

Pathogens in Brazilian wild canids and domestic dogs

Curi, N. H. A., Araújo, A. S., Campos, F.S., Lobato, Z. I. P., Gennari, S. M., Marvulo, M. F. V., Silva, J. C. R. & Talamoni,S A. 2010. Wild canids, domestic dogs and their pathogens in Southeast Brazil: disease threats for canid conservation. Biodiversity and Conservation 19: 3513-3524.

Wild canids are under many pressures, including habitat loss, fragmentation and disease. The current lack of information on the status of wildlife health may hamper conservation efforts in Brazil. In this paper, we examined the prevalence of canine pathogens in 21 free-ranging wild canids, comprising 12 Cerdocyon thous (crab-eating fox), 7 Chrysocyon brachyurus (maned wolf), 2 Lycalopex vetulus (hoary fox), and 70 non-vaccinated domestic dogs from the Serra do Cipó National Park area, Southeast Brazil. For wild canids, seroprevalence of antibodies to canine parvovirus, canine adenovirus, canine coronavirus and Toxoplasma gondii was 100 (21/21), 33 (7/21), 5 (1/19) and 68 (13/19) percent, respectively. Antibodies against canine distemper virus, Neospora caninum or Babesia spp. were not found. We tested domestic dogs for antibodies to canine parvovirus, canine distemper virus and Babesia spp., and seroprevalences were 59 (41/70), 66 (46/70), and 42 (40/70) percent, respectively, with significantly higher prevalence in domestic dogs for CDV (P < 0.001) and Babesia spp. (P = 0.002), and in wild canids for CPV (P < 0.001). We report for the first time evidence of exposure to canine coronavirus in wild hoary foxes, and Platynossomun sp. infection in wild maned wolves. Maned wolves are more exposed to helminths than crab-eating foxes, with a higher prevalence of Trichuridae and Ancylostomidae in the area. The most common ectoparasites were Amblyomma cajennense, A. tigrinum, and Pulex irritans. Such data is useful information on infectious diseases of Brazilian wild canids, revealing pathogens as a threat to wild canids in the area. Control measures are discussed.

Dog pathogens in threatened wild canids

Deem, Sharon L., & Louise H. Emmons. 2005. Exposure of free-ranging maned wolves (Chrysocyon brachyurus) to infectious and parasitic disease agents in the Noel Kempff Mercado National Park, Bolivia. Journal of zoo and wildlife medicine 36 (2): 192-197.

Maned wolves (Chrysocyon brachyurus) are neotropic mammals, listed as a CITES Appendix II species, with a distribution south of the Amazon forest from Bolivia, through northern Argentina and Paraguay and into eastern Brazil and northern Uruguay. Primary threats to the survival of free-ranging maned wolves include habitat loss, road kills, and shooting by farmers. An additional threat to the conservation of maned wolves is the risk of morbidity and mortality due to infectious and parasitic diseases. Captive maned wolves are susceptible to, and die from, common infectious diseases of domestic dogs (Canis familiaris) including canine distemper virus (CDV), canine parvovirus (CPV), rabies virus, and canine adenovirus (CAV). Results from this study show that free-ranging maned wolves in a remote area of Bolivia have been exposed to multiple infectious and parasitic agents of domestic carnivores, including CAV, CDV, CPV, canine coronavirus, rabies virus, Leptospira interrogans spp., Toxoplasma gondii, and Dirofilaria immitis, and may be at increased risk for disease due to these agents.

Disease impact of dogs

Vanak, A. T., Belsare, A. V. & Gompper, M. E. 2007. Survey of Disease Prevalence in Free-Ranging Domestic Dogs and Possible Spill-Over Risk for Wildlife – A Case Study from the Great Indian Bustard Sanctuary, Maharashtra - India. Final report submitted to the Rufford Small Grants Foundation, UK. Pp 1-13

Domestic dogs are the world’s most common carnivore, and yet the ecology of free-ranging  dogs has rarely been investigated. Many dog populations are subsidized by humans resulting in  high population density, which presumably also have contact rates above the critical threshold  that allows diseases to persist enzootically within the population. Domestic dogs are the  reservoir of infectious diseases that have led to epidemics of rabies, canine distemper and  canine parvovirus in several wild carnivore species, yet little is known about the disease ecology  of domestic dogs in India, and the potential for spill-over risk to wildlife. This project was carried out to assess the disease exposure and health status of free-ranging domestic dogs in the vicinity of a wildlife reserve in central India. We carried out a sero-prevalence survey of canine distemper virus (CDV), canine parvovirus (CPV) and rabies in the dog population surrounding the Great Indian Bustard Sanctuary in Nannaj, Maharashtra. We sampled 74 dogs from four villages surrounding the wildlife reserve and obtained blood samples for testing for IgM and IgG antibodies to CDV and CPV. We also collected salivary swabs from 31 dogs to test for rabies antigen. Antibodies to CPV were detected in 93.3% of the sampled dogs, while 90.7% of dogs had evidence for recent or past exposure to CDV. This suggests that these diseases are enzootic in the dog population, and may pose a significant threat to wild carnivores if disease control measures are not implemented. Rabies was also detected in 2 (6%) of the dogs tested, raising human health concerns as well. We recommend a comprehensive vaccination and dog population control policy as well as an education campaign on responsible dog ownership among villagers.

Urban dogs as a source of virus for wild carnivores

Acosta-Jamett, G., Cleaveland, S., Cunningham, A. A., & Bronsvoort, B. M. D. (2010). Demography of domestic dogs in rural and urban areas of the Coquimbo region of Chile and implications for disease transmission. Preventive veterinary medicine, 94(3), 272-281.

A cross-sectional household questionnaire survey was conducted along two transects (80 and 45 km long) from Coquimbo and Ovalle cities to the Fray Jorge National Park (FJNP) in the Coquimbo region of Chile in 2005–2007 to investigate the demography of dogs in the context of a study of canine infectious diseases. Data were collected on the number of dogs per household, fecundity, mortality, and sex and age distribution. The results from 1021 households indicated that dog ownership was common, with a higher proportion of households owning dogs in rural areas (89%), than in towns (63%) or cities (49%). Dog density ranged from 1380 ± 183 to 1509 ± 972 dogs km^-2 in cities, from 119 ± 18 to 1544 ± 172 dogs km^-2 in towns, and from 1.0 ± 0.4 to 15.9 ± 0.4 dogs km^-2 in rural sites. The dog population was estimated to be growing at 20% in cities, 19% in towns and 9% in rural areas. The human:dog ratio ranged from 5.2 to 6.2 in cities, from 2.3 to 5.3 in towns, and from 1.1 to 2.1 in rural areas. A high percentage of owned dogs was always allowed to roam freely in the different areas (27%, 50% and 67% in cities, towns and rural areas, respectively). Observations of free-roaming dogs of unknown owner were reported from a greater proportion of respondents in cities (74%), followed by towns (51%) and finally by rural areas (21%). Overall only 3% of dogs had been castrated. In addition, only 29% of dogs were reported to have been vaccinated against canine distemper virus (CDV) and 30% against canine parvovirus (CPV). The higher population size and density, higher growth rate and a higher turnover of domestic dogs in urban than in rural areas and the poorly supervised and inadequately vaccinated dog populations in urban areas suggest that urban areas are more likely to provide suitable conditions for dogs to acts as reservoirs of pathogenic infections.

Acosta-Jamett, G., Chalmers, W. S. K., Cunningham, A. A., Cleaveland, S., Handel, I. G., & Bronsvoort, B. M. (2011). Urban domestic dog populations as a source of canine distemper virus for wild carnivores in the Coquimbo region of Chile. Veterinary microbiology, 152(3), 247-257.

Urban areas can support dog populations dense enough to maintain canine distemper virus (CDV) and can be a source of infection for rural dogs and free-ranging carnivores. The aim of this study was to investigate the relationships between urban and rural domestic dog and wild carnivore populations and their effects on the epidemiology of CDV to explain retrospectively a CD outbreak in wild foxes in 2003. From 2005 to 2007 a cross-sectional household questionnaire survey was conducted in Coquimbo and Ovalle cities, in three towns and in rural sites along two transects from these cities to the Fray Jorge National Park (FJNP) in the Coquimbo region, Chile. Blood samples were collected from unvaccinated dogs at surveyed households and from free-ranging foxes in rural areas along the transects. The seroprevalence of CDV in domestic dogs was higher in urban than in rural areas and in the later was highest in dogs born before 2001–2002. The seroprevalence of CDV in foxes was higher in areas closer to human settlements. A high seroprevalence in dogs born before 2001–2002 further supports a link between CDV patterns in rural dog and fox populations. In our study area, urban dogs are proposed to be the source of CDV infection to wild carnivores. The large dog population size and density detected in Coquimbo and Ovalle provides optimal conditions for maintaining a large and dense susceptible population of dogs, which can act as a reservoir for highly infectious diseases and could have been the source of infection in the CD outbreak in wild foxes.

Canine virus impact on island fox

Clifford, D.L., J.A.K. Mazet, E.J. Dubovi, D.K. Garcelon, T.J. Coonan, P. A. Conrad & L. Munson. 2006. Pathogen exposure in endangered island fox (Urocyon littoralis) populations: Implications for conservation management. Biological Conservation, 131: 230 – 243

Island fox (Urocyon littoralis) populations on four California Channel Islands have declined severely since 1994. Canine distemper (CDV) was suspected to be responsible for the decline of the Santa Catalina Island fox, so knowledge of infectious disease exposure in the remaining island fox populations was urgently needed. This study reviewed previous pathogen exposure in island foxes and investigated the current threat by conducting a serologic survey of foxes on all islands and sympatric feral cats on three islands from 2001 to 2003 for antibodies against canid pathogens. Before the decline, foxes had evidence of exposure to CDV, canine adenovirus (CAV), canine parvovirus (CPV), and Toxoplasma, with exposure to these five pathogens differing greatly by island. Exposure to canine coronavirus (CCV), canine herpesvirus (CHV), and Leptospira was rare. In 2001–2003, wild-born foxes had evidence of exposure to CDV (5.2–32.8%) on 5 of 6 islands, CPV (28–100%) and CAV (4.7–100%) on five islands, and Toxoplasma gondii (2.3–15.4%) on four islands. Exposure to CCV, CHV and Leptospira was less common. Sharing of infectious agents between sympatric foxes and feral cats appeared minimal, but CDV exposure was detected in two cats on Santa Catalina Island. Domestic dogs have historically been present on the islands, but it is not known if canine diseases can be maintained in fox populations without the continual presence of dogs. Targeted vaccination programs against the most virulent pathogens and continued intensive disease surveillance may help protect the critically small remaining fox population

Iberian lynx naïf to domestic carnivores pathogens

Roelke ME, Johnson WE, Millán J, Palomares F, Revilla E, Rodríguez A, Calzada J, Ferreras P, León-Vizcaíno, Delibes M & O’Brien SJ. 2008. Exposure to disease agents in endangered Iberian lynx (Lynx pardinus). European Journal of Wildlife Research, 54: 171-178

The Iberian lynx (Lynx pardinus) is the most endangered felid species in the world. Lynx populations have decreased dramatically in size and distribution in the last four decades, thus becoming increasingly vulnerable to catastrophic events such as epizooties. From 1989 to 2000, serum samples were obtained from 48 free-ranging lynx captured in the Doñana National Park (DNP, n = 31) and mountains of Sierra Morena (SM, n = 17) in southern Spain. Samples were tested for antibodies against Toxoplasma gondii, feline herpesvirus 1 (FHV-1), feline calicivirus (FCV), feline/canine parvovirus (FPV/CPV), feline coronavirus, feline immunodeficiency virus (FIV), feline leukaemia virus and canine distemper virus (CDV) and for FeLV p27 antigen, to document baseline exposure levels. Antibodies against T. gondii were detected in 44% of lynx, with a significantly greater prevalence in DNP (61%) than in SM (12%). In DNP, prevalence was significantly higher in adult (81%) than in juvenile and sub-adult (41%) lynx, but no such difference was observed in SM. Low prevalences (≤11%) of minimally positive titres were found for FHV-1, FCV and FPV/CPV. This, combined with the lack of evidence for exposure to CDV, FIV and FeLV, suggests that these lynx populations are naïve and might be vulnerable to a disease outbreak in the future. Because of the reduced size of lynx populations, the documented low level of genetic variation (particularly in the DNP population) coupled with the recently documented state of immune depletion in a majority of necropsied lynx, it is important to better understand the threat and potential impact that disease agents might pose for the conservation of this endangered species. Future surveillance programs must include possible disease reservoir hosts such as domestic cats and dogs and other wild carnivores.