Patterns and processes of pathogen exposure in gray wolves across North America.

The presence of many pathogens varies in a predictable manner with latitude, with infections decreasing from the equator towards the poles. We investigated the geographic trends of pathogens infecting a widely distributed carnivore: the gray wolf (Canis lupus). Specifically, we investigated which variables best explain and predict geographic trends in seroprevalence across North American wolf populations and the implications of the underlying mechanisms. We compiled a large serological dataset of nearly 2000 wolves from 17 study areas, spanning 80° longitude and 50° latitude. Generalized linear mixed models were constructed to predict the probability of seropositivity of four important pathogens: canine adenovirus, herpesvirus, parvovirus, and distemper virus-and two parasites: Neospora caninum and Toxoplasma gondii. Canine adenovirus and herpesvirus were the most widely distributed pathogens, whereas N. caninum was relatively uncommon. Canine parvovirus and distemper had high annual variation, with western populations experiencing more frequent outbreaks than eastern populations. Seroprevalence of all infections increased as wolves aged, and denser wolf populations had a greater risk of exposure. Probability of exposure was positively correlated with human density, suggesting that dogs and synanthropic animals may be important pathogen reservoirs. Pathogen exposure did not appear to follow a latitudinal gradient, with the exception of N. caninum. Instead, clustered study areas were more similar: wolves from the Great Lakes region had lower odds of exposure to the viruses, but higher odds of exposure to N. caninum and T. gondii; the opposite was true for wolves from the central Rocky Mountains. Overall, mechanistic predictors were more informative of seroprevalence trends than latitude and longitude. Individual host characteristics as well as inherent features of ecosystems determined pathogen exposure risk on a large scale. This work emphasizes the importance of biogeographic wildlife surveillance, and we expound upon avenues of future research of cross-species transmission, spillover, and spatial variation in pathogen infection.

Dual infection with an emergent strain of canine distemper virus and canine parvovirus in an Arctic wolf under managed care.

A 6-wk-old managed male Arctic wolf with lethargy, drooling, dehydration, elevated temperature, and acute onset of seizures was submitted for autopsy. The wolf had been vaccinated with a multivalent vaccine exactly 2 wk prior to presentation. Grossly, long bones were brittle and easily fractured under pressure; the intestinal contents were mucoid and yellow. Histologically, there was widespread lymphoid and hematopoietic necrosis, failure of endochondral ossification within long bones, as well as intranuclear and intracytoplasmic inclusions in various tissues and cell types. Canine distemper virus was detected in numerous tissues by IHC and confirmed by RT-rtPCR and sequencing as an American-4 strain, an emerging strain in domestic dogs and wildlife species in the southeastern United States. The clinical and pathologic findings associated with this emergent CDV strain have not been reported previously in wolves, to our knowledge. Canine parvovirus 2 (CPV-2b) was also detected in the spleen by IHC and confirmed by conventional PCR as a wild-type strain. The exact impact of CPV-2b on the clinical course is unknown. Early vaccination in this case may have predisposed this Artic wolf to developing clinical disease.

Genetic Characterization of Canine Adenovirus Type 1 Detected by Real-Time Polymerase Chain Reaction in an Oral Sample of an Italian Wolf (Canis Lupus).

We report the detection of canine adenovirus type 1 DNA by real-time PCR technique in an oral sample of an Italian wolf (Canis lupus italicus). Genetic characterization of the virus revealed a strict relationship with viruses detected in dogs (Canis lupus familiaris), wolves, and red foxes (Vulpes vulpes), suggesting that transmission between wild animals and dogs had occurred.

Identification of Pantropic Canine Coronavirus in a Wolf ( Canis lupus italicus) in Italy.

We report a case in an Italian wolf ( Canis lupus italicus) of pantropic canine coronavirus infection, which has previously been detected only in dogs. The wolf was coinfected by canine parvovirus type 2b and canine adenovirus type 2, which highlighted the crucial role of epidemiologic surveys in European wild carnivores.

A SEROSURVEY OF DISEASES OF FREE-RANGING GRAY WOLVES (CANIS LUPUS) IN MINNESOTA, USA.

We tested serum samples from 387 free-ranging wolves ( Canis lupus ) from 2007 to 2013 for exposure to eight canid pathogens to establish baseline data on disease prevalence and spatial distribution in Minnesota's wolf population. We found high exposure to canine adenoviruses 1 and 2 (88% adults, 45% pups), canine parvovirus (82% adults, 24% pups), and Lyme disease (76% adults, 39% pups). Sixty-six percent of adults and 36% of pups exhibited exposure to the protozoan parasite Neospora caninum . Exposure to arboviruses was confirmed, including West Nile virus (37% adults, 18% pups) and eastern equine encephalitis (3% adults). Exposure rates were lower for canine distemper (19% adults, 5% pups) and heartworm (7% adults, 3% pups). Significant spatial trends were observed in wolves exposed to canine parvovirus and Lyme disease. Serologic data do not confirm clinical disease, but better understanding of disease ecology of wolves can provide valuable insight into wildlife population dynamics and improve management of these species.

PREVALENCE OF ANTIBODIES FOR SELECTED CANINE PATHOGENS AMONG WOLVES (CANIS LUPUS) FROM THE ALASKA PENINSULA, USA.

We collected blood samples from wolves ( Canis lupus ) on the Alaska Peninsula, southwest Alaska, US, 2006-11 and tested sera for antibodies to canine adenovirus (CAV), canine coronavirus (CCV), canine distemper virus (CDV), canine herpesvirus (CHV), canine parainfluenza (CPI), canine parvovirus (CPV), Neospora caninum , and Toxoplasma gondii . Detected antibody prevalence was 90% for CAV, 28% for CCV, 12% for CDV, 93% for CHV, 0% for CPI, 20% for CPV, 0% for N. caninum, and 86% for T. gondii . Prevalence of CCV antibodies suggested a seasonal pattern with higher prevalence during spring (43%) than in fall (11%). Prevalence of CCV antibodies also declined during the 6-yr study with high prevalence during spring 2006-08 (80%, n=24) and low prevalence during spring 2009-11 (4%, n=24). Prevalence of N. caninum and T. gondii antibodies were highly variable in the study area during 2006-11. Results suggested that some pathogens might be enzootic on the Alaska Peninsula (e.g., CAV and CHV) while others may be epizootic (e.g., CCV, N. caninum , T. gondii ).

Patterns of Exposure of Iberian Wolves (Canis lupus) to Canine Viruses in Human-Dominated Landscapes.

Wildlife inhabiting human-dominated landscapes is at risk of pathogen spill-over from domestic species. With the aim of gaining knowledge in the dynamics of viral infections in Iberian wolves (Canis lupus) living in anthropized landscapes of northern Spain, we analysed between 2010 and 2013 the samples of 54 wolves by serology and polymerase chain reaction (PCR) for exposure to four pathogenic canine viruses: canine distemper virus (CDV), canine parvovirus-2 (CPV), canine adenovirus 1 and 2 (CAV-1 and CAV-2) and canine herpesvirus. Overall, 76% of the studied wolves presented evidence of exposure to CPV (96% by HI, 66% by PCR) and 75% to CAV (75% by virus neutralization (VN), 76% by PCR, of which 70% CAV-1 and 6% CAV-2). This represents the first detection of CAV-2 infection in a wild carnivore. CPV/CAV-1 co-infection occurred in 51% of the wolves. The probability of wolf exposure to CPV was positively and significantly correlated with farm density in a buffer zone around the place where the wolf was found, indicating that rural dogs might be the origin of CPV infecting wolves. CPV and CAV-1 appear to be enzootic in the Iberian wolf population, which is supported by the absence of seasonal and inter-annual variations in the proportion of positive samples detected. However, while CPV may depend on periodical introductions by dogs, CAV-1 may be maintained within the wolf population. All wolves were negative for exposure to CDV (by VN and PCR) and CHV (by PCR). The absence of acquired immunity against CDV in this population may predispose it to an elevated rate of mortality in the event of a distemper spill-over via dogs.

Presence of anti-Toxoplasma gondii, -Neospora caninum, - Leishmania spp. and -Ehrlichia canis antibodies in free-ranging maned wolves (Chrysocyon brachyurus) in the northeastern region of the state of São Paulo, Brazil / Presença de anticorpos anti-Toxoplasma gondii, -Neospora caninum, -Leishmania spp. e - Ehrlichia canis em lobos-guará (Chrysocyon brachyurus) de vida livre na Região Nordeste do Estado de São Paulo, Brasil

The maned wolf (Chrysocyon brachyurus), an inhabitant of the Brazilian savanna, is considered the largest canid of South America and is classified as a near-threatened species by the International Union for Conservation of Nature (IUNC). The purpose of this study was to investigate the presence of antibodies against Toxoplasma gondii, -Neospora caninum, - Leishmania spp., and -Ehrlichia canis in free-ranging maned wolves in the northeastern region of the state of São Paulo, Brazil. Of the 17 serum samples tested by the indirect fluorescent antibody test (IFAT), 88.2% (15/17), 17.6% (3/17) and 52.9% (9/17) showed anti-T. gondii, -Leishmania spp., and -E. canis antibodies, respectively. None of the studied maned wolves tested positive for N. caninum antibodies. Our results indicated the exposure of free-ranging maned wolves to the agents in question. The presence of industrial complexes, extensive agriculture and habitat fragmentation in the northeastern region of the state of São Paulo puts these wild animals in proximity to urban areas, possibly contributing to the transmission of diseases between wild and domestic animals and human beings.(AU)

O lobo-guará (Chrysocyon brachyurus) habita o ecossistema de Cerrado e é considerado o maior canídeo da América do Sul e uma espécie ameaçada de extinção pela "International Union for Conservation of Nature" (IUNC). O objetivo desse estudo foi investigar a presença de anticorpos anti-Toxoplasma gondii, -Neospora caninum, -Leishmania spp. e -Ehrlichia canis em lobosguará da região nordeste do estado de São Paulo, Brasil. Das 17 amostras de soro testadas por meio da reação de imunofluorescência indireta (RIFI), 88,2% (15/17), 17,6% (3/17) e 52,9% (9/17) apresentaram anticorpos anti-T. gondii, - Leishmania spp. e -E. canis, respectivamente. Todos os animais testados foram soronegativos para N. caninum. Esses resultados indicam a exposição dos lobos-guará dessa região aos agentes pesquisados. A presença de um complexo industrial, agricultura extensiva e fragmentação de habitat na região nordeste do estado de São Paulo, favorece a proximidade desses animais silvestres a ambientes urbanos o que pode contribuir para a transmissão de doenças entre os animais silvestres, domésticos e o homem.(AU)

Occurrence of antibodies against Leptospira spp. in free-ranging wild canids from the Brazilian savanna / Ocorrência de anticorpos contra Leptospira spp. em canídeos selvagens de vida livre do cerrado brasileiro

The Brazilian savanna, also known as Cerrado, is one of the world's richest and most ecologically invaluable tropical savanna regions. There are few studies in Brazil about the diseases that affect the wild canids of this biome, which may be harmful to wildlife populations and public health. The aim of this study was to evaluate the occurrence of antibodies against Leptospira spp. in three Cerrado wild canids species using the microscopic agglutination test (MAT). Serum samples were tested from 19 crab-eating foxes (Cerdocyon thous), 14 maned wolves (Chrysocyon brachyurus), and seven hoary foxes (Lycalopex vetulus), all free-ranging animals found in the municipalities of Araguari and Uberlândia, Minas Gerais State, and Cumari, Goiás State, Brazil. Fourteen (35%) of these samples were seropositive. The most frequent serovars detected in the samples were Copenhageni and Hardjo, but reactions to the serovars Autumnalis, Grippotyphosa, Hebdomadis, Wolffi, and Icterohaemorrhagiae also occurred. Notwithstanding other reported results, this study is the first to report the presence of antibodies against Leptospira spp. in L. vetulus. The three species of wild canids examined may act as potential hosts for several serovars of leptospira in Brazil's savanna environment...

O cerrado é a mais diversificada savana tropical do mundo e constitui grande importância ecológica. Ainda assim, são poucos os estudos realizados no Brasil a respeito das doenças que acometem os canídeos desse bioma, o que causa prejuízos à população de animais selvagens e à saúde pública. Essa pesquisa foi realizada com o objetivo de avaliar a ocorrência de anticorpos contra Leptospira spp. em três espécies de canídeos selvagens do cerrado brasileiro utilizando o teste de soroaglutinação microscópica (SAM). Foram testadas amostras de soro sanguíneo de 19 cachorros-do-mato (Cerdocyon thous), 14 lobos guarás (Chrysocyon brachyurus) e sete raposas-do-campo (Lycalopex vetulus) de vida livre das regiões de cerrado de Araguari e Uberlândia, MG, e Cumari, GO. Dessas 40 amostras, 14 (35%) foram soropositivas. Os sorovares detectados com maior frequência foram Copenhageni e Hardjo, porém evidenciou-se também reação aos sorovares Autumnalis, Grippotyphosa, Hbedomadis, Wolffi e Icterohaemorrhagiae. Esse trabalho foi o primeiro a relatar a presença de anticorpos anti-Leptospira spp. em L. vetulus e verificou-se que as três espécies de canídeos utilizadas nessa pesquisa podem atuar como possíveis hospedeiros de diversos sorovares de leptospiras no ambiente de cerrado...

Pathogens of wild maned wolves (Chrysocyon brachyurus) in Brazil.

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.