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In European countries, raccoon dogs (Nyctereutes procyonoides) are believed to impact ecosystems and potentially threaten native species. In this study, the stomachs of 525 raccoon dogs culled in Danish wetlands were analysed and compared to 53 stomachs of adult raccoon dogs killed by vehicles, from the countryside. The stomach content was analysed using traditional macroscopic technics supplemented by eDNA analysis. The diet of raccoon dogs in wetlands did not differ notably from that of raccoon dogs in other parts of Denmark except for the larger amount of bait, and less shrews and fruit. More than 80% of the diet of adult raccoon dogs in wetlands consisted of bait, birds (mainly ducks taken in autumn and songbirds), amphibians, carrion, berries, fruit, and grass. Also, insects (mainly larger beetles and aquatic insects) occurred in the diet of raccoon dogs in wetlands. Waterfowl eaten during the autumn and winter are likely to be migrating birds. A high number of carrion beetles and fly maggots indicates a high consumption of carrion of all kinds. Eggs of ground-nesting birds made up a negligible part of the raccoon dog's diet. eDNA-analysis found no trace of shorebirds and only common species of amphibians were recorded. This study provides no evidence that raccoon dogs are a threat to ground-nesting birds nor to endangered amphibians in Danish wetlands. [ABSTRACT FROM AUTHOR]

Simple Summary: Raccoon dogs have been farmed for economic purposes for ~100 years, and white raccoon dogs are among the most famous breeds of farmed raccoon dogs. However, white raccoon dogs are weaker in fitness than normal raccoon dogs. Purging potentially deleterious mutations while maintaining a white coat is the goal for breeders. For the first time, we performed whole-genome sequencing of a white raccoon dog population and performed a comparative analysis with normal raccoon dogs. We found a smaller effective population size for the white raccoon dogs within the last 100 years. The overall inbreeding in the two types of raccoon dogs was found to be very similar, but recently occurring inbreeding was found to be more extensive in white raccoon dogs. Interestingly, the total number of deleterious mutations in the white raccoon dogs is comparable to that in the normal raccoon dogs. However, the proportion of homozygous missense mutations in white raccoon dogs is greater than that in normal raccoon dogs, indicating that the accumulation of small-effect deleterious mutations may be facilitated during the development of white breeds. The formation of animal breeds usually begins with a small subsample from their ancestral population. Deleterious mutations accumulate in the population under genetic drift, inbreeding, and artificial selection during the development and maintenance of traits desired by humans. White raccoon dogs are among the most popular breeds of farmed raccoon dogs, but white raccoon dogs are more susceptible to disease and have a lower reproductive ability. However, the accumulation of deleterious mutations in this white breed is largely unknown. By analyzing and comparing whole-genome sequencing data from 20 white raccoon dogs and 38 normal raccoon dogs, we detected an increased occurrence of loss-of-function (LoF) mutations in white raccoon dogs compared with normal raccoon dogs. With the finding of a significantly higher dosage of homozygous missense mutations in the white raccoon dog genome, we detected a greater fitness cost in white raccoon dogs. Although a much higher FROH level for ROH fragments longer than 1 Mb has been reported in white raccoon dogs, we did not detect a genetic signal of genetic purging in white raccoon dogs. This study provides valuable genomic resources and new insights into the accumulation of mutation loads in farmed raccoon dogs. [ABSTRACT FROM AUTHOR]

Simple Summary: Prion diseases are rare and fatal neurodegenerative disorders associated with the shadow of the prion protein (SPRN) gene. Raccoon dogs, members of the Canidae family, may exhibit resistance to these diseases, yet the specific factors underlying this resistance remain unidentified. In this study, we amplified and analyzed the SPRN gene in raccoon dogs using PCR and DNA sequencing, identifying five novel genetic polymorphisms. In silico analysis assessed the pathogenic potential of these insertion/deletion polymorphisms, indicating that they are non-pathogenic. This research marks the first exploration of the genetic and structural characteristics of the SPRN gene in raccoon dogs. Prion diseases, or transmissible spongiform encephalopathies (TSEs), are a group of invariably fatal neurodegenerative disorders. One of the candidate genes involved in prion diseases is the shadow of the prion protein (SPRN) gene. Raccoon dogs, a canid, are considered to be a prion disease-resistant species. To date, the genetic polymorphisms of the SPRN gene and the predicted protein structure of the shadow of prion protein (Sho) have not been explored in raccoon dogs. SPRN was amplified using polymerase chain reaction (PCR). We also investigated the genetic polymorphisms of SPRN by analyzing the frequencies of genotypes, alleles, and haplotypes, as well as the linkage disequilibrium among the identified genetic variations. In addition, in silico analysis with MutPred-Indel was performed to predict the pathogenicity of insertion/deletion polymorphisms. Predicted 3D structures were analyzed by the Alphafold2. We found a total of two novel synonymous single nucleotide polymorphisms and three insertion/deletion polymorphisms. In addition, the 3D structure of the Sho protein in raccoon dogs was predicted to resemble that of the Sho protein in dogs. This is the first study regarding the genetic and structural characteristics of the raccoon dog SPRN gene. [ABSTRACT FROM AUTHOR]

Raccoon dog was proposed as a potential host of SARS-CoV-2, but no evidence support such a notion. In our study, we investigated the binding affinities of raccoon dog ACE2 (rdACE2) to the spike (S) protein receptor binding domain (RBD) of SARS-CoV-2 prototype (PT) and its variants. It revealed that the binding affinities of RBD from SARS-CoV-2 variants were generally lower than that of the PT RBD. Through structural and functional analyses, we found amino acids H34 and M82 play pivotal roles in maintaining the binding affinity of ACE2 to different SARS-CoV-2 sub-variants. These results suggest that raccoon dogs exhibit lower susceptibility to SARS-CoV-2 compared to those animal species with a high prevalence of SARS-CoV-2 transmission. Author summary: In our study, we investigated the potential role of raccoon dogs as hosts for SARS-CoV-2 by examining the binding affinities between the spike (S) protein receptor binding domain (RBD) of SARS-CoV-2 prototype (PT) and its variants with the ACE2 receptor from raccoon dogs (rdACE2). Our findings revealed that the binding affinities of the RBD from most of SARS-CoV-2 variants to rdACE2 were generally lower compared to the PT RBD. Detailed structural and functional analyses identified two key amino acids, H34 and M82, which are crucial in preserving the binding affinity of ACE2 to different SARS-CoV-2 sub-variants. These results indicate that raccoon dogs have a lower susceptibility to SARS-CoV-2 compared to other animal species known for a high prevalence of SARS-CoV-2 transmission. This study provides valuable insights into the host range of SARS-CoV-2 and highlights the importance of specific amino acid residues in ACE2 for virus-receptor interactions. Understanding these interactions is essential for assessing the zoonotic potential of SARS-CoV-2 and implementing effective measures to prevent interspecies transmission of the virus. [ABSTRACT FROM AUTHOR]

ABSTRACT Invasive raccoons (Procyon lotor) naturalized in Hokkaido, Japan, potentially spreading infectious diseases. Canine distemper virus infection is a serious epizootic disease, for which the raccoon is one of the hosts. We investigated the virus's prevalence in Hokkaido's wild raccoons, using 611 serum samples collected from captured raccoons in 2007–2012, 2021, and 2022. Higher seropositivity rates were confirmed in 2007 (32.7%), 2021 (46.4%), and 2022 (46.8%) than in 2008–2012 (0.00%–6.06%), suggesting the occurrence of an epidemic in 2007, 2021, and 2022 and its disappearance in 2008–2012. However, the infection status has recently changed, with high seropositivity rates consecutively confirmed in 2021 and 2022. Logistic regression analysis was performed to investigate the relationships among the catch per unit effort (an index of animal population density), host and environmental factors, and antibody status. The catch per unit effort correlated with seropositivity in 2007. As for environmental factors, the forest area ratio had a weak influence on seroprevalence in 2007; however, the residential area ratio had a clear influence on seroprevalence in 2021 and 2022. The epidemic occurred in forested areas in 2007; nonetheless, recent raccoon population growth and habitat expansion may have caused widespread infections even around residential areas in 2021 and 2022. Continuous monitoring of the infection and reinforcement of raccoon control programs are necessary to avoid serious damage through disease transmission to sympatric native raccoon dog (Nyctereutes procyonoides) and fox (Vulpes vulpes) populations, as well as health consequences for domestic dogs (Canis familiaris). [ABSTRACT FROM AUTHOR]

Archaeological research has mainly focused on stone tools, pottery, and metal relics excavated from ruins. Recently, interest in natural relics such as animal bones has increased, as these relics can provide insight into the eating habits, cultural level, and perception of animals of the people at that time. This study investigated morphological structures and dimensions of Nyctereutes procyonoides bones excavated from a well at the Gasan-ri archaeological site in Jinju. These bones are presumed to be relics from the Three Kingdoms period. A total of 447 animal bones were excavated, of which 59 (13.2%) were identified as N. procyonoides bones. These identified bones weighed 47.14 g, accounting for 4.83% of the total bone weight (975.30 g). These N. procyonoides bones were found to belong to 2 individuals estimated to be 5 to 6 weeks old. These bones included 5 skull fragments, 2 mandibles, 9 vertebrae, 11 ribs, 10 forelimb bones, 3 hip bones, and 19 hindlimb bones. A fracture was observed near the bregma of one skull. The presence of a complete specimen in the well suggested that it was used in animal sacrifice rituals. This study estimated the value of animals and human dietary culture at that time by utilizing N. procyonoides bones presumed to be relics of the Three Kingdoms period. [ABSTRACT FROM AUTHOR]

Simple Summary: Sarcoptic mange is a highly contagious disease affecting various animals. In this study, skin samples from wild boars in South Korea confirmed the presence of Sarcoptes scabiei, the mite that causes sarcoptic mange, and genetic analysis of the cox-1 gene showed that the mites shared an identical haplotype. A serological survey of 658 wild boars across South Korea found that 5.47% of the animals had antibodies to Sarcoptes scabiei, indicating prior exposure. These findings indicate that sarcoptic mange may be prevalent within the wild boar population in South Korea, highlighting the importance of ongoing monitoring and control efforts to protect wildlife. Sarcoptic mange, caused by Sarcoptes scabiei, has been reported in various wildlife species, with the potential to impact populations. While it has been documented in some wildlife species and domestic animals, it has not been previously reported in wild boars in South Korea. In March and April 2022, skin samples from nine wild boars and one raccoon dog with suspected sarcoptic mange were submitted to the NIWDC. These samples were tested and confirmed the presence of S. scabiei in six wild boars and one raccoon dog. Genetic analysis of the cox-1 gene from mites indicated that the gene was identical and belonged to the same haplotype in both host species. Serological survey of 658 wild boars, collected from March 2022 to February 2023, revealed a nationwide seroprevalence of 5.47%. The highest seroprevalence was in Gyeongsangnam-do (9.82%); however, regional differences in seroprevalence across the country were not statistically significant, suggesting the disease may be endemic across South Korea. Seroprevalence was highest in spring (16.84%), likely due to increased contact during winter. This study provides fundamental data on the genetic characteristics and distribution of S. scabiei mites in South Korean wild boars, emphasizing the need for continued surveillance to prevent further spread. [ABSTRACT FROM AUTHOR]

Simple Summary: Cryptosporidium and Giardia are single-cell parasites that can infect both animals and humans, causing diarrhea and risks to public health. Both parasites can be found in nearly all mammals, including domestic dogs, red foxes, and raccoon dogs, which can act as natural carriers and spread them through direct contact, food, and the environment. This study aimed to understand how common these protozoans are in Latvia and what factors influence their occurrence in domestic and wild canids. We collected fecal samples from 373 domestic dogs, 219 red foxes, and 78 raccoon dogs and tested for the presence of Cryptosporidium and Giardia duodenalis. Red foxes and raccoon dogs had higher prevalence of both parasites than domestic dogs. Puppies showed higher infection rates with both parasites. All infected canids were more likely to have both parasites simultaneously. This research highlights the need for responsible pet care and a potential zoonotic risk for humans. Cryptosporidium spp. and Giardia duodenalis are zoonotic food- and water-borne protozoa of veterinary importance. They are one of the main causes of diarrhea in domestic dogs (Canis familiaris). Wild canids, such as red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides), can act as natural reservoirs for these parasites. The aim of this study was to estimate the prevalence of these pathogens and analyze possible factors that may affect the infection in wild and domestic canids. A total of 373 domestic dog, 219 red fox, and 78 raccoon dog fecal samples were collected and tested for Cryptosporidium spp. and G. duodenalis presence with direct immunofluorescent staining. The dog owners filled a questionnaire on the dog's habits and lifestyle to identify and analyze potential factors that may affect the occurrence of these parasites in dogs. Cryptosporidium spp. were found in 16.3%, 28.3%, and 28.2% and G. duodenalis in 0.7%, 27.4%, and 30.8% of the examined dogs, red foxes, and raccoon dogs, respectively. The highest prevalence was observed in puppies—15.4% and 18.5% for Cryptosporidium spp. and G. duodenalis, respectively. In all three canid species, infection with Cryptosporidium increases the risk of co-infection with Giardia and vice versa. [ABSTRACT FROM AUTHOR]

Changes in craniometric traits of the raccoon dog (Nyctereutes procyonoides) in the samples from one locality separated by a 30-year time interval were analyzed. Small differences in both metric and nonmetric cranial traits were found. Sexual dimorphism was expressed weakly. For a set of 13 metric traits, significant differences were found in young and adult males in samples separated by a 30-year time interval. No such differences were found in either young or adult females. Analysis of skull aberrations showed a slightly higher level of divergence for a number of traits. Several new phenes of nonmetric traits, which were absent in the 1990s sample, were found among individuals captured in the 2020s, indicating a certain increase in diversity in the raccoon dog population over the 30-year period. A weak chronographic variability of cranial features compared to other species of Canidae was found, which was attributed by the authors to a number of physiological peculiarities of the raccoon dog. [ABSTRACT FROM AUTHOR]

The article presents the results of a comprehensive craniological analysis of the common raccoon dog (Nyctereutes procyonoides Gray 1834) based on adult skulls from four samples, three of which comprise materials from Ukraine: 1) central and northern oblasts of Ukraine (Kyiv, Chernihiv, and Cherkasy oblasts); 2) eastern oblasts of Ukraine (Luhansk, Zaporizhzhia, and Poltava oblasts); 3) southern oblasts of Ukraine (Kherson Oblast). Additionally, a sample that includes materials from the native range of the species (Khabarovsk Krai, Primorsky Krai, and Chita Oblast of Russia) was also analysed. The research included standard analysis based on craniometric measurements of 19 parameters, and analysis of the skull shape by tools of geometric morphometrics separately for the dorsal and ventral sides of the skull and the buccal surface of the left mandible. The total sample comprised 62 specimens. The results of the analysis of linear characters showed that specimens from the northern, central, and southern oblasts of Ukraine differ from those from the eastern oblasts of Ukraine and from specimens from the Far East, which are characterised by larger dimensions. The analysis of shape differences using MorphoJ demonstrates the greatest morphological distance between the samples from the territory of Ukraine and the sample from the species’ native range. The analysis of the dorsal and ventral surfaces of the skulls showed that the specimens from the native range of the common raccoon dog have more elongated and broader nasal bones, while the braincase is narrowed from the sides, but elongated towards the occipital bones. The greatest level of shape variation is characteristic of the mandible. Specimens from the territory of Ukraine have a more elongated mandibular ramus and a larger area of the coronal, articular, and angular processes, while skulls from the species’ native range have a larger angle between the mandibular ramus and the coronal process, which in turn has a greater inclination relative to the articular process and a smaller area of the angular process. Skull size is often larger in animals in introduced populations, but it also depends on environmental conditions, nutrition, and interspecific competition.

Social Impact Statement Gingko biloba is an iconic tree with a surprising connection to the SARS and Covid viruses that have impacted human health since 2003. Natural history studies on the ecology of Gingko seed dispersal by Carnivoran scavengers in Asia over the past 30 plus years have elucidated the deep evolutionary history that not only makes these animals effective at spreading seeds but also predisposes them to become intermediate hosts for spreading diseases to humans. Understanding the behavioral traits that underlie these kinds of plant–animal interactions has the potential to help people limit the spread of future spillover diseases. Summary Raccoon dogs and masked palm civets are Carnivoran scavengers native to Eastern Asia that have been documented feeding on the malodorous sarcotesta of Ginkgo biloba seeds and effectively dispersing the hard nuts they contain. Research has shown that their immune systems are genetically enhanced to protect them from the disease‐causing organisms they might pick up from their omnivorous diets that include live and dead animals. Both species are farmed for fur and meat across China and, up until recently, were commonly sold in “wet” markets. Research has determined that the palm civet played a role in spreading the SARS virus to humans in 2003 and that the raccoon dog may have played a similar role in spreading Covid in Wuhan in 2019, although this has not been proven. In areas where Ginkgo is cultivated, there are numerous internet reports of Carnivorans feeding on its seeds indicating that its dispersal strategy of attracting scavengers by mimicking the smell of carrion is adaptive and effective.

The COVID-19 pandemic, caused by SARS-CoV-2, demonstrated that zoonotic transmission of animal sarbecoviruses threatens human health but the determinants of transmission are incompletely understood. Here, we show that most spike (S) proteins of horseshoe bat and Malayan pangolin sarbecoviruses employ ACE2 for entry, with human and raccoon dog ACE2 exhibiting broad receptor activity. The insertion of a multibasic cleavage site into the S proteins increased entry into human lung cells driven by most S proteins tested, suggesting that acquisition of a multibasic cleavage site might increase infectivity of diverse animal sarbecoviruses for the human respiratory tract. In contrast, two bat sarbecovirus S proteins drove cell entry in an ACE2-independent, trypsin-dependent fashion and several ACE2-dependent S proteins could switch to the ACE2-independent entry pathway when exposed to trypsin. Several TMPRSS2-related cellular proteases but not the insertion of a multibasic cleavage site into the S protein allowed for ACE2-independent entry in the absence of trypsin and may support viral spread in the respiratory tract. Finally, the pan-sarbecovirus antibody S2H97 enhanced cell entry driven by two S proteins and this effect was reversed by trypsin while trypsin protected entry driven by a third S protein from neutralization by S2H97. Similarly, plasma from quadruple vaccinated individuals neutralized entry driven by all S proteins studied, and availability of the ACE2-independent, trypsin-dependent pathway reduced neutralization sensitivity. In sum, our study reports a pathway for entry into human cells that is ACE2-independent, can be supported by TMPRSS2-related proteases and may be associated with antibody evasion. Author summary: Bats host a wide range of coronaviruses, including those related to SARS-CoV-1 and SARS-CoV-2 (subgenus Sarbecovirus), but their ability to infect human cells remains poorly understood. Identifying sarbecoviruses with zoonotic potential and understanding the factors controlling their entry into human cells are crucial for risk assessment and antiviral development. In this study, we examined how bat sarbecovirus spike proteins facilitate entry into human cells and identified key host factors involved. Using pseudovirus particles, we show that several bat sarbecovirus spike proteins use human and animal ACE2 receptors for entry. Additionally, we confirm that some spike proteins utilize an ACE2-independent entry pathway requiring trypsin treatment and demonstrate that this process is controlled by the spike protein receptor binding domain. Furthermore, we reveal that a subset of ACE2-using bat sarbecovirus spike proteins can switch to ACE2-independent entry following trypsin exposure and show that certain human type II transmembrane serine proteases can substitute for trypsin, enabling ACE2-independent entry. Finally, we demonstrate that repeated COVID-19 vaccination generates cross-neutralizing activity against bat sarbecoviruses, though ACE2-independent entry reduces neutralization sensitivity. [ABSTRACT FROM AUTHOR]

Background: Carnivore parvovirus is commonly detected in canines and felines and results in a range of symptoms, including diarrhoea, with a high lethality rate. In recent years, the gradual restoration of urban ecosystems coupled with a lack of natural predators means that wild raccoon dogs have gradually entered residential neighbourhoods in Shanghai, and the carnivore parvovirus carried by such canines may seriously affect their health and that of dogs and cats in these neighbourhoods. Objectives: Therefore, it is essential to monitor wild raccoon dogs for carnivore parvovirus. Methods: The wild raccoon samples were collected from the residential area of Shanghai and screened for parvovirus, followed by virus isolation and sequence comparison analysis. Results: In this study, three strains of parvovirus, YSH1‐2022, YSH2‐2022 and GSW1‐2023, were isolated from anal and pharyngeal swab mixtures of 42 live raccoon dogs and two dead raccoon dogs in Shanghai, China. After alignment, it was found that the three strains of parvovirus were all located in the same branch as feline panleukopenia virus (FPV), and the three VP2 genes had 100% homology with FPV VP2 genes isolated from Shanghai and Yangzhou, Jiangsu Province. The homology of the three NS1 genes with FPV NS1 isolated from Shanghai and other places was 99.9%–100%. Conclusion: This is the first report of FPV isolated from raccoon dogs. In this study, the host range and risk of infection of parvovirus were evaluated, providing data to support wildlife management and policy formulation in Shanghai. [ABSTRACT FROM AUTHOR]

Social Impact Statement: Gingko biloba is an iconic tree with a surprising connection to the SARS and Covid viruses that have impacted human health since 2003. Natural history studies on the ecology of Gingko seed dispersal by Carnivoran scavengers in Asia over the past 30 plus years have elucidated the deep evolutionary history that not only makes these animals effective at spreading seeds but also predisposes them to become intermediate hosts for spreading diseases to humans. Understanding the behavioral traits that underlie these kinds of plant–animal interactions has the potential to help people limit the spread of future spillover diseases. Summary: Raccoon dogs and masked palm civets are Carnivoran scavengers native to Eastern Asia that have been documented feeding on the malodorous sarcotesta of Ginkgo biloba seeds and effectively dispersing the hard nuts they contain. Research has shown that their immune systems are genetically enhanced to protect them from the disease‐causing organisms they might pick up from their omnivorous diets that include live and dead animals. Both species are farmed for fur and meat across China and, up until recently, were commonly sold in "wet" markets. Research has determined that the palm civet played a role in spreading the SARS virus to humans in 2003 and that the raccoon dog may have played a similar role in spreading Covid in Wuhan in 2019, although this has not been proven. In areas where Ginkgo is cultivated, there are numerous internet reports of Carnivorans feeding on its seeds indicating that its dispersal strategy of attracting scavengers by mimicking the smell of carrion is adaptive and effective. [ABSTRACT FROM AUTHOR]

Monitoring both native and invasive species is crucial for understanding their ecological impacts. However, obtaining reliable data can be challenging, especially for elusive species like mesopredators. This study utilized snow-track surveys in Finland (1989–2022) to examine population trends of the invasive raccoon dog and the native red fox. While raccoon dogs are known to reduce activity during cold weather, we demonstrated that accounting for temperature and snowfall allows for effective population trend estimation using snow-track data. Track accumulation decreased in cold and snowy weather more clearly for raccoon dogs than for red foxes. We also found that the track accumulation of the raccoon dog had significantly increased, while those of the red fox population had declined, particularly in southern parts of the country. Notably, raccoon dog snow-track numbers increased in northern regions, suggesting a potential for further range expansion under a warming climate. These findings reveal a concerning shift in Finland's mesopredators abundance due to the invasive species' success and the decline of the native species. Thus, the invasive raccoon dog is likely to have an increasing role in those northern ecosystems where it interacts with the native fauna. [ABSTRACT FROM AUTHOR]

Wind farms are still developing dynamically worldwide, with promising prospects for further growth. Therefore, the assessment of their impact on animals has been carried out. So far, few studies have been conducted on game mammals, and their results are divergent. Previous studies on the impact of wind farms on game species were typically based on regional research covering one or, at most, several wind farms. In this study, we aimed to verify the effect of wind farms on the density of game mammals through a large-scale analysis at the country level, using lowland Poland as an example. The study was based on hunting bag data from open-field hunting districts. It covered seven game species: roe deer (Capreolus capreolus), wild boar (Sus scrofa), red fox (Vulpes vulpes), raccoon dog (Nyctereutes procyonoides), European badger (Meles meles), European polecat (Mustela putorius), and European hare (Lepus europaeus). We used Corine Land Cover to account for differences in land cover and the area covered by wind farms in generalized linear mixed models. The study showed that in agricultural landscapes, mainly herbivorous species of game mammals were related to land cover types. These species tend to exhibit higher densities in agricultural areas containing more natural landscape features. Conversely, mesocarnivores are primarily driven by the abundance of prey with little to no observable effects from land cover types. Only roe deer and wild boar presented lower densities with an increase in the area covered by wind farms (for roe deer: estimate: − 0.05, 95% CI: − 0.1–0.0; for wild boar: estimate: − 0.03, 95% CI: − 0.11–0.05), while no effect was observed for mesocarnivores or European hare. The underlying reasons for these relationships remain unclear and require more specific studies. The uncertainty regarding the cause of the observed effects did not allow for a large-scale assessment of the impact of further wind energy development on the studied game mammals. [ABSTRACT FROM AUTHOR]

Simple Summary: Habitat loss and fragmentation from extensive road development have escalated wildlife–vehicle collisions (WVCs) as a major cause of wildlife mortality. This study covers 9 years of WVC data across South Korea, examining species involved, seasonal and regional variations, and road factors affecting WVCs, to analyze impacts and propose mitigation strategies. Over 4561 km of roads were monitored, yielding insights into the connection between WVCs, road characteristics, and species-specific patterns. The study identified 13,606 WVCs involving 143 terrestrial vertebrate species, with detailed patterns and models for the top seven mammal species. Spatial differences in WVCs appeared more related to wildlife habitats, but some road features correlated variably with WVC frequency, highlighting complex prevention challenges. Effective mitigation requires comprehensive strategies tailored to species traits, seasonality, and road types. Severe habitat loss and fragmentation due to extensive road development have escalated wildlife–vehicle collisions (WVCs) as one of the major causes of wildlife mortality. This study, spanning 9 years from 2009 to 2017, presents comprehensive WVC data in South Korea, including species composition, seasonal and regional patterns, and road factors influencing WVCs, aiming to analyze their impact and propose effective mitigation strategies. We collected WVC data with road variables for 9 years from 4561 km of nationwide monitoring road sections and analyzed the data to understand the relationship between WVCs and road characteristics, as well as species-specific patterns. A nationwide survey identified 13,606 WVCs involving 143 terrestrial vertebrate species, and patterns and models of the top seven mammal species (raccoon dog (Nyctereutes procyonoides), Siberian chipmunk (Eutamias sibiricus), Siberian weasel (Mustela sibirica), water deer (Hydropotes inermis), red squirrel (Sciurus vulgaris), Korean hare (Lepus coreanus), and leopard cat (Prionailurus bengalensis)) were presented. Patterns revealed declines in WVCs overall, except for water deer. Although spatial differences in WVCs seemed linked more to wildlife habitats, certain road features correlated both positively or negatively with WVC frequency, highlighting complexities in the effectiveness of preventative measures. For effective mitigation and prevention of WVCs, comprehensive strategies considering species traits, seasonality, and road types should be implemented [ABSTRACT FROM AUTHOR]

Minks, cats, and some other species of carnivores are susceptible of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and have a high risk of transmitting SARS-CoV-2 to humans. The development of animal vaccines can be an effective measure to protect animals against SARS-CoV-2 and reduce the potential risk of human infection. We previously developed a messenger ribonucleic acid (mRNA) vaccine SYS6006 that has been proven to be an efficient coronavirus disease 2019 (COVID-19) vaccine widely used in humans. Here, we further evaluated the safety and immunogenicity of SYS6006 as an animal COVID-19 vaccine candidate for SARS-CoV-2 susceptible animals or wild animals. SYS6006 was safe and immunogenic in mice and completely protected mice against mouse-adapted SARS-CoV-2 infection in the upper and lower respiratory tracts. SYS6006 was able to induce neutralizing antibodies against the SARS-CoV-2 wild-type, Delta, and Omicron BA.2 strain on day 7 after prime immunization, and two doses of immunization could enhance the neutralizing antibody responses and produce long-lasting potent antibodies for more than 8 months in minks and cats, blue foxes, and raccoon dogs, while all immunized animals had no abnormal clinical signs during immunization. These results provided here warrant further development of this safe and efficacious mRNA vaccine platform against animal COVID-19. [ABSTRACT FROM AUTHOR]

Habitat preferences of invasive predators determine where and for which prey species they pose a threat upon. This is crucial information for the conservation of endangered prey species because invasive predators pose additional predation on top of that caused by natural predators. In large parts of Europe, the most common invasive mesopredator is the raccoon dog (Nyctereutes procyonoides). To understand the risk that the raccoon dog poses for wetland-associated species, we collected information about its habitat preferences near these habitats. We used data on 24 GPS-collared raccoon dogs from three landscape types in Finland, to study their spatial and temporal habitat preferences. We first determined their home ranges, within which we then examined habitat use and preferences. Raccoon dogs showed generalist habitat use, which was evident in their wide range of used habitats. However, in spring and summer, during the breeding seasons of waterfowl and amphibians, they preferred wetlands and peatlands. They also preferred shorelines and the edges of forests and agricultural fields. During autumn and winter, raccoon dogs did not prefer wetlands. These findings support the conclusion that the raccoon dog's habitat preferences pose a particular threat to wetland-associated species, such as nesting waterfowl and amphibians. The species' habitat preferences coupled with high numbers of this invasive mesopredator pose additional predation for endangered wetland-associated species on top of that of native predators. [ABSTRACT FROM AUTHOR]

Summary: Nematodes associated with the carcass beetle Creophilus maxillosus were examined. The beetles were collected from the decomposed body of a dead racoon dog Nyctereutes procyonoides in Kyoto, Japan, and dissected for examination of internal parasites. The dissected beetles were kept on agar plates for isolation of phoretic species. Although no parasites were found, three species of phoretic associates, Caenorhabditis plicata , Diplogastrellus cf. gracilis and Rhabditidoides sp., were recognised, and two species were later successfully cultured as laboratory strains. Diplogastrellus cf. gracilis and Rhabditidoides sp. were compared to an authentic strain of D. gracilis (German strain, SB306) and two presumably conspecific strains (German strain RS5443 and Japanese strain NKZ346), respectively, by mating experiments and molecular sequence comparison. The comparisons revealed that D. cf. gracilis is conspecific to D. gracilis SB306, and three Rhabditidoides strains are new conspecific species. The typological and molecular characters of D. gracilis are described and compared with other populations of the species, and Rhabditidoides sp. is taxonomically described as Rhabditidoides eutrophicola n. sp. [ABSTRACT FROM AUTHOR]

Simple Summary: The Korean raccoon dog (Nyctereutes procyonoides koreensis) is an important species in Korea. However, there has been little research about its joint anatomy. In this study, we investigated the anatomy of the limb joints of the Korean raccoon dog using joint orientation angles, a method frequently used in humans, dogs, and cats. The findings of this study should be helpful not only for individual therapies, such as fracture repair, but also for comparative anatomy. Furthermore, this study is the first to measure joint orientation angles in wild animals such as the Korean raccoon dog, making it a useful reference for measurements in other wild canids. Studies are being conducted on the anatomical structures of various wild animals. Despite the ecological importance of the Korean raccoon dog (Nyctereutes procyonoides koreensis), limited research has been conducted on its anatomical structure. This study is the first to establish a reference range for joint orientation angles in the limbs of the Korean raccoon dog. Joint orientation angles are an unexplored concept not only in Korean raccoon dogs but also in other wildlife. However, they are important in the examination of the skeletal anatomy of humans and companion animals, such as dogs and cats. Because this type of measurement is still emerging in wildlife research, we applied the methodology used in the domestic dog (Canis lupus familiaris). Angles were measured between the mechanical or anatomical axis and the joint orientation lines in the thoracic and pelvic limbs of Korean raccoon dogs. No significant differences were observed between the sexes or between the left and right sides. These findings are consistent with those observed in domestic dogs. Based on this study, a reference range of joint orientation angles could be established for Korean raccoon dogs. [ABSTRACT FROM AUTHOR]

With the increase in the number of urban wildlife, some residents feel anxious and fearful due to the presence of wildlife in urban communities, even when there is no direct physical conflict between them. This research aims to analyze the role of citizen science in increasing residents' tolerance towards urban wildlife. This research takes the communities with the highest raccoon dog density in Shanghai as the research sites. Forty respondents were selected from local community by systematic sampling. Information was collected through semi-structured interviews and participatory observation. This research used NVivo 12 for thematic analyses. The research found that residents who did not participate in citizen science tended to take crisis observation. They regard raccoon dogs as dangerous wildlife and strictly monitor their behavior to prevent them from causing harm to humans. Residents who are engaging in citizen science tend to take scientific observations. They rationally and objectively record raccoon dogs' behavior, numbers, and distribution. Based on the experience of scientific observation, residents who had participated in citizen science anthropomorphically observed raccoon dogs in their daily lives and established an emotional bond with them. This research found that citizen science enhances residents' tolerance towards urban wildlife by producing knowledge and perceiving animal selfhood. In conclusion, this research reveals the complex relationship between residents and wildlife in urban communities by incorporating animals into sociological analysis. [ABSTRACT FROM AUTHOR]

Canine adenovirus type 2 (CAV-2) is a common causative agent of respiratory disease in canines. There have been no reports of CAV-2 variants isolated from raccoon dogs. This study aims to investigate the biological and genetic characteristics of a novel Korean CAV-2 variant. Madin-Darby canine kidney cells were used to isolate the CAV-2 variant from 45 fecal swab samples. Diagnostic tools such as the cytopathic effect (CPE) assay, electron microscopy, polymerase chain reaction, and immunofluorescence and hemagglutination assays were used to confirm the presence of the CAV-2 isolate. A cross-virus neutralization assay was performed to verify the novelty of this CAV variant. Genetic analysis was performed using nucleotide sequences obtained through next-generation sequencing. The isolate was confirmed to be a CAV-2 variant based on the aforementioned methods and designated CAV2232. The number of bases in the fiber and E3 genes of CAV2232 were 1,626 and 414, respectively. Phylogenetic analysis of the fiber and E3 genes confirmed that CAV2232 was classified into a different clade from the known CAV-1 and CAV-2 strains. Mice inoculated with the CAV2232 vaccine developed high virus neutralization antibody titers of 1,024 (210) against CAV2232, while mice inoculated with CAV-1 and CAV-2 vaccines had low virus neutralization antibody titers of 12.9 (23.7) and 6.5 (22.7), respectively, against CAV2232. CAV2232 isolated from wild raccoon dog feces was classified as a novel CAV-2 variant. CAV2232 may therefore be used as an antigen for new vaccine development and serological investigations. [ABSTRACT FROM AUTHOR]

Sustainable wildlife management requires reliable data on population, habitat, and the interaction between them. Since 1993, Hungary has maintained the National Game Management Database, which collects data on game populations and hunting bags annually. During the last three decades, populations of medium-sized predators have remarkably increased in the country. Our study analyzed changes in hunting bag data and spatial distribution of two invasive alien species, the raccoon (Procyon lotor) and the raccoon dog (Nyctereutes procyonoides), utilizing annual game management reports from Game Management Units from 1997 to 2021. For spatial analysis, we employed a UTM grid system (10 × 10 km) covering the country. Our findings confirmed increasing trends in the hunting bag and area (number of grid cells) containing hunting bags for both species. From the first (1997–2001) to the last (2017–2021) period, the average annual hunting bag increased (raccoon: 0.40 → 11.00 ind/year; raccoon dog: 3.40 → 8.00 ind/year), and the average number of cells with hunting bags also expanded significantly (raccoon: 2.00 → 9.60 UTM cells/year; raccoon dog: 5.80 → 15.20 UTM cells/year). These trends and the size of potentially suitable habitats suggest a further spread and population increase, posing challenges for nature conservationists and wildlife managers. [ABSTRACT FROM AUTHOR]

Background: In recent years, the trichomonosis in raccoon dogs in China had occurred frequently. Pentatrichomonas hominis had been described in raccoon dogs in China in some previous studies. Purpose To Reveal: whether raccoon dogs can be infected by other trichomonad species besides P. hominis, and clarify the prevalence and species distribution of trichomonad in raccoon dogs. Methods: Herein, the 389 fecal samples were collected from farm-raised raccoon dogs in Hebei Province, all the samples were detected using the microscopic examination and several fecal samples containing trichomonad-like organisms were processed, cultured, stained, and photographed. Meanwhile, all the samples were screened by the species-specific nested PCR based on the small subunit rRNA (SSU rRNA) gene of P. hominis,Tritrichomonas foetus and Tetratrichomonas buttreyi, respectively, and all positive secondary PCR amplications obtained in this study were sequenced, aligned and analysed. Results: 62 fecal samples (15.9%,62/389) were trichomonad-positive under light microscopy, and the trichomonad-like cells were clearly observed in the culture contents. The PCR results showed that 100 samples were trichomonad-positive, including 45 P. hominis-positive samples (11.6%,45/389), 32 T. foetus-positive samples (8.2%,32/389), and 33 T. buttreyi-positive samples (8.5%,33/389), respectively. Double mixed infections were observed in 10 samples. The prevalence of T. foetus and P. hominis were both significantly higher in raccoon dogs with diarrhea (13.9%, and 25.0%) than that in raccoon dogs without diarrhea (7.6%, and 9.3%) (p < 0.05).All samples confirmed as trichomonad-positive under microscopy were also found to be trichomonad-positive by PCR analysis. The sequencing and phylogenetic analysis demonstrated the sequences obtained in this study belonged to P. hominis, T. foetus and T. buttreyi SSU rRNA, respectively. Among them, the T. buttreyi SSU rRNA sequences obtained in this study harbored the new sequence polymorphisms. Based on preliminary morphological and molecular analyses, raccoon dogs are considered as the new host of T. foetus and T. buttreyi. Conclusion: This is the first report about the identifcation and prevalence of T. foetus and T. buttreyi in raccoon dogs in China, and the results increase our knowledge about the host range and prevalence of trichomonad species. [ABSTRACT FROM AUTHOR]

The impact of infectious diseases on host populations is often not quantified because it is difficult to observe the host population and infectious disease dynamics. To address this problem, we developed a state-space model to simultaneously estimate host population and disease dynamics using wildlife rescue data. Using this model, we aimed to quantify the impact of sarcoptic mange on a Japanese raccoon dog population by estimating the change in their relative population size. We classified the status of rescued raccoon dogs into four categories: i) rescued due to infection with mange, ii) rescued due to traffic accidents without mange, iii) rescued due to traffic accidents with mange, and iv) rescued due to causes other than traffic accidents or mange. We modelled the observation process for each category and fitted the model to the reported number of raccoon dogs rescued between 1990 and 2010 at three wildlife rescue facilities in Kanagawa Prefecture, Japan. The mortality rate induced by mange was estimated to be 1.09 (95% credible interval (CI): 0.47–1.72) per year. The estimated prevalence of sarcoptic mange ranged between 4 and 80% in the study period. When a substantial prevalence of mange was observed (1995–2002), the host population size decreased by 91.2% (95% credible intervals: 86.3–94.7). We show that the impact of infectious disease outbreak on the wildlife population can be estimated from the time-series data of wildlife rescue events due to multiple causes. Our estimates suggest that sarcoptic mange triggered a substantial decrease in the Japanese wild raccoon dog populations.

Canine distemper (CD) is a virulent disease caused by the canine distemper virus (CDV) in canines and mustelidaes with high mortality. The incidence of CDV is worldwide distribution and it has caused huge economic losses to multiple industries around the world. There are many studies investigating the prevalence of CD infection, but no comprehensive analysis of CDV infection in minks, foxes and raccoon dogs worldwide has therefore been carried out. The aim of this meta is to provide a comprehensive assessment of the prevalence of CDV infection in minks, foxes and raccoon dogs dogs through a meta-analysis of articles published from around the world. Data from 8,582 small carnivores in 12 countries were used to calculate the combined prevalence of CD. A total of 22.6% (1,937/8,582) of minks, foxes and raccoon dogs tested positive for CD. The prevalence was higher in Asia (13.8, 95% CI: 22.2-45.6), especially in South Korea (65.8, 95% CI: 83.3-95.8). Our study found that the incidence of CD was also associated with geographic climate, population size, health status, and breeding patterns. CD is more commonly transmitted in minks, foxes and raccoon dogs. However, the concentrated breeding as an economic animal has led to an increase in the prevalence rate. The difference analysis study recommended that countries develop appropriate preventive and control measures based on the prevalence in the minks, foxes, and raccoon dogs industries, and that reducing stocking density is important to reduce the incidence of CDV. In addition, CDV is more common in winter, so vaccination in winter should be strengthened and expanded to reduce the incidence of CD in minks, foxes and raccoon dogs. [ABSTRACT FROM AUTHOR]

Introduction: Intrapulmonary arteriovenous anastomoses (IPAVAs) are defined as relatively large, dynamic shunt vessels that connect the pulmonary arterial and venous systems, thereby bypassing the pulmonary capillary system. IPAVAs lower elevated pulmonary arterial pressure; however, the presence of the shunt can result in impaired pulmonary gas exchange and paradoxical embolism. Furthermore, the prevalence and effects of IPAVAs in raccoon dogs remain unknown. This study aimed to determine the prevalence of IPAVA among rescued Korean raccoon dogs and evaluate the changes in IPAVA following oxygen supplementation. Methods: Nineteen raccoon dogs rescued by the Jeonbuk Wildlife Centre between August 2022 and December 2023 were subjected to echocardiography. Sixteen healthy and three abnormal raccoon dogs were subjected to transthoracic agitated saline contrast echocardiography (bubble study) based on the echocardiography results. IPAVA was considered to be present if the left heart contrast was visualised after four cardiac cycles following the visualisation of the first right heart contrast. Bubble scores (BS0-5) were assigned based on the maximum number of microbubbles observed in the left ventricular lumen per frame of the ultrasound image. BS was assigned before and after supplementation with 100% oxygen for 5 min. Results: IPAVA was detected in 12 of the 16 healthy raccoon dogs at rest (75%). The BS of the 15 IPAVA-positive raccoon dogs ranged from 1 to 4 points (BS1, 1; BS2, 4; BS3, 8; and BS4, 2). Blood flow through the IPAVA (QIPAVA) was reduced or absent in the 15 IPAVA-positive raccoon dogs after supplementation with 100% oxygen (BS0, 11; BS2, 4). Moreover, BS of the IPAVA showed a significant correlation with the cardiac output per body weight (BW). Conclusion: The prevalence of IPAVA in healthy raccoon dogs at rest was 75%. Adequate oxygen supplementation was found to be effective in reducing QIPAVA, which may help prevent potential negative factors such as pulmonary gas exchange impairments and paradoxical embolismthat can occur with IPAVA. [ABSTRACT FROM AUTHOR]

Various domestic and wildlife species have been found susceptible to and infected with SARS‐CoV‐2, the causative agent of COVID‐19, around the globe, raising concerns about virus adaptation and transmission to new animal hosts. The virus circulation in the white‐tailed deer population in North America has further called to action for virus surveillance in the wildlife. Here, we report on the first SARS‐CoV‐2 survey of wild animals in Japan, where frequent wildlife invasions of urban areas have occurred due to the limited predation, field abandonment, the increase of human acclimatization. Genetic testing using nasal swabs and serological screening have been conducted for sika deer, brown bears, raccoons, and raccoon dogs captured in Hokkaido prefecture from the end of the Delta variant wave to the spread of the Omicron variant, between March 2022 and February 2023. No viral RNA was detected in raccoons (0/184), sika deer (0/107), and brown bears (0/14) indicating that the virus was unlikely to spread within the population of these animal species. Among 171 raccoons, 20 raccoon dogs, 100 sika deer, and 13 brown bears, one raccoon, one brown bear, and two deer tested positive in the antibodies screening with multispecies SARS‐CoV‐2 N‐protein ELISA. Still, ELISA‐positive samples tested negative in three other serological tests, emphasizing the importance of confirming serological screening results. Our results suggested that SARS‐CoV‐2 was unlikely to spillback from humans to wildlife in Hokkaido during the study period, with the emergence of new variants, continuous surveillance is of utmost importance. [ABSTRACT FROM AUTHOR]

The Nyctereutes procyonoides is highly regarded in the farming and leather industries because of the high value of its fur, which renders artificial feeding a crucial aspect. However, high-fat diets have always been associated with a variety of digestive disorders. This study aimed to investigate the impact of high-fat diets on the gut microbiota and the mechanisms of gut damage in Nyctereutes procyonoides. 16S rRNA sequencing demonstrated that high-fat diets caused diarrhea and intestinal damage through alterations in the gut microbiota: a decrease in the abundance of Firmicutes, an increase in the abundance of Proteobacteria and Actinobacteria, and an increase in the abundance of Enterococcaceae, Escherichia coli-Shigella, Clostridium and Lactobacillus. Subsequently, changes in metabolic pathways, such as amino and fatty acid pathways, were identified by KEGG and COG enrichment analysis, and the TLR4/NF-κB/NLRP3 inflammatory signaling pathway was shown to be activated by high-fat diets. In addition, high-fat diets lead to the accumulation of ROS and MDA and reduce the activity of the antioxidant enzymes GSH-PX and SOD. Correspondingly, the levels of proinflammatory cytokines (IL-6, IL-1β and TNF-α) were significantly increased, and the apoptosis and necrosis signaling pathways of colonic cells were detected, causing a dramatic decrease in the expression of intestinal tight junction proteins (Occludin, E-cadherin, ZO-1 and ZO-2). In conclusion, high-fat diets altered the structure of the Nyctereutes procyonoides gut microbiota community and led to colon damage. This study provides new insights into the intestinal health of Nyctereutes procyonoides. Highlights: 1. High-fat diets result in disruption of Nyctereutes procyonoides intestinal flora. 2. High-fat diets cause functional and metabolic disturbances in the intestinal flora. 3. Disorders of gut microbiota induce inflammatory response, oxidative stress, and intestinal barrier disruption in the Nyctereutes procyonoides colon. [ABSTRACT FROM AUTHOR]

Whether an invasive species thrives in cold ecosystems depends on its response to winter weather. A potential threat to these ecosystems in Europe is the invasive raccoon dog (Nyctereutes procyonoides). The survival of this mesopredator is supported in cold weather, because it can periodically use winter sleep, but its winter activity levels compared to native mesopredators remain unclear. We investigated the winter behaviour of raccoon dogs in Finland, near the edge of their invasion front, and compared their activity to native red foxes and badgers. Using wildlife cameras, we found that raccoon dogs do reduce activity during the coldest months, but camera observations did not strongly correlate with temperature perhaps due to feeding at camera sites. That is, artificial food sources may have increased raccoon dogs' winter activity. Nevertheless, they responded more clearly to temperature drops than red foxes, but were more active than badgers that were mostly dormant and thus absent from our data. GPS-tracked raccoon dogs remained at some level active through winter, even near subarctic regions, but the cold and snowy weather clearly decreased activity and individuals stayed close to their nests during the coldest periods. Overall, these findings suggest that raccoon dogs can maintain some winter activity even in extremely cold environments, and they readily exploit human-provided resources. This potential ability to thrive in cold regions highlights the invasive potential of raccoon dogs. As winters become milder due to climate change, their numbers could increase significantly within cold-adapted ecosystems, impacting native species and posing conservation challenges. [ABSTRACT FROM AUTHOR]

The Asiatic raccoon dog (Nyctereutes procyonoides) has successfully colonized Northern, Eastern, and Central Europe, following 20th century introductions. While subject to eradication campaigns, its ecological impacts remain incompletely understood and debated. This study aims to examine the habitat preference and movement patterns of raccoon dogs in Denmark using GPS telemetry data. Habitat selection patterns were examined seasonally using Jacob's electivity index. Movement intensity (travel speed) was examined according to temporal and environmental predictors such as time of day, time of year and habitat type. Raccoon dogs showed an overall preference for peatbogs, marshes, and broadleaf tree cover, and an overall avoidance of water bodies (per se), artificial surfaces and constructions, natural material surfaces (e.g., river pebble banks, beaches, sand dunes), cultivated areas, coniferous tree cover and herbaceous vegetation, and a close to neutral selection pattern for moors and heathland. Habitat usage was generally consistent throughout the seasons for all habitat types, apart from minor shifts observed, particularly from November to February. The raccoon dog exhibited a unimodal nocturnal activity pattern throughout all seasons, with highest mean travel speeds occurring during spring and lowest during winter. Prolonged periods of higher mean daily speeds were observed during autumn. Mean speed levels also varied according to habitat type, with raccoon dogs moving slower in habitats they preferred and faster in those they did not prefer. These results indicate that raccoon dogs in Denmark adjust their habitat selection and movement patterns throughout the year, with a general preference for moist and high tree coverage areas. This information can be utilized in forecasting models for their potential future range and area use in different regions. [ABSTRACT FROM AUTHOR]

Introduction: Nyctereutes procyonoides koreensis (Korean raccoon dog), a member of the Canidae family, is anatomically similar to dogs. Previous studies have used vertebral heart scale measurements to measure the cardiac size of Korean raccoon dogs on thoracic radiographs; however, the use of additional cardiac size indices, such as vertebral left arial score, intercostal space, cardiothoracic ratio, and echocardiographic indices, has not been reported. Therefore, this study aimed to establish normal reference ranges for various thoracic radiographic and echocardiographic indices in normal Korean raccoon dogs. Methods: Twenty-six Korean raccoon dogs (11 males and 15 females) were included in this study. The thoracic radiographic indices, vertebral heart scale score, and vertebral left atrial score were measured in the right lateral view. The intercostal space and cardiothoracic ratio were measured in the ventrodorsal view. The echocardiograms were evaluated in the right parasternal long and short axis view and left parasternal apical view. Results: The mean values for the thoracic radiographic and echocardiographic indices were as follows: vertebral heart scale, 9.12 ± 0.74; vertebral left atrial score, 1.5 ± 0.31; intercostal spaces, 3.17 ± 0.34; cardiothoracic ratio, 0.69 ± 0.07; left atrial to aortic root ratio, 1.22 ± 0.14; main pulmonary artery to aorta ratio, 1.22 ± 0.14; left ventricular end-diastolic internal diameter normalized for body weight, 1.36 ± 0.19; end-diastolic volume index, 51.07 ± 19.6; end-systolic volume index, 16.54 ± 7.45; the peak velocity of early diastolic transmitral flow, 73.13 ± 15.46 cm/s; and the ratio between the transmitral flow velocities and the peak early diastolic velocity, 1.77 ± 0.47. Only percent increase in the left ventricular end-systolic internal diameter was negatively correlated with body weight. The remaining indices showed no correlations with body weight. Conclusion: To the best of our knowledge, this is the first case report covering both thoracic radiographic and endocardiographic indices for Korean raccoon dogs. Thus, the thoracic radiographic and echocardiographic indices established in this study may be used to evaluate the cardiac condition of Korean raccoon dogs. [ABSTRACT FROM AUTHOR]

Camera traps have been widely used in wildlife research, offering significant potential for monitoring species interactions at ephemeral resources. However, raw data obtained from camera traps often face limitations due to observation censoring, where resource consumption by dominant animals may obscure potential resource use by less dominant animals. We extended time‐to‐detection occupancy modeling to quantify interspecific consumptive competition and redundancy of ecosystem functions through consumption between two species, while accounting for observation censoring. By treating resource use by rival species as censored data, we estimated the proportion of resources potentially used in the absence of rival species and calculated the loss caused by the rival species, which is defined as "Competition Intensity Index." We also defined the Unique Functional Contribution, which represents the net functional loss when a species is removed, calculated by excluding the contribution potentially substituted by the other species. We also considered resource degradation and computed the quantity of resources acquired by each species. This established framework was applied to predation data on bird nests by alien squirrels and other predators (Case 1) as well as scavenging on mammalian carcasses by two carnivores (Case 2). In Case 1, the introduction of squirrels significantly affected the breeding success of birds. Although nests were being preyed upon by native crows also, our model estimated that Unique Functional Contribution by the squirrels was 0.47. This means that, by eradicating the squirrels, the reproductive success of the birds could potentially increase by as much as 47%. In Case 2, the Competition Intensity Index for foxes was 0.17, whereas that for raccoon dogs was 0.46, suggesting an asymmetric effect of resource competition between the two species. The frequency distribution of wet mass available to the two species differed significantly. This approach will enable a more robust construction of resource–consumer interaction networks. [ABSTRACT FROM AUTHOR]

Purpose: The immunogenicity of vaccines containing the canine adenovirus (CAdV) type 2 (CAdV-2) variant has not yet been reported. We prepared a novel inactivated CAdV-2 variant vaccine using the CAV2232-41 strain, and evaluated its safety and immunogenicity in raccoon dogs. Materials and Methods: The growth kinetics of CAV2232-41 were determined using Madin-Darby Canine Kidney (MDCK) cells. The nucleotide sequences of CAV2232 and CAV2232-41 were determined by next-generation sequencing. To generate the CAdV-2 variant vaccine, CAV2232-41 propagated in the MDCK cells was inactivated with 0.1% formaldehyde. Two vaccines were prepared by blending inactivated CAV2232-41 with Cabopol and Rehydragel adjuvants. Safety and immunogenicity of the CAV2232C and CAV2232R vaccines were evaluated in guinea pigs. Safety and immunogenicity of the CAV2232C vaccine were also evaluated in raccoon dogs. The virus neutralizing antibody (VNA) titer against CAV2232-41 was measured in sera collected from immunized guinea pigs and raccoon dogs. Results: CAV2232-41 showed the highest viral titer on days 4-6 post-inoculation and had a deletion in the E3 gene, which was confirmed as a CAdV-2 variant. Guinea pigs inoculated with CAV2232C showed slightly higher VNA titers than those inoculated with CAV2232R 2 weeks after booster vaccination. Raccoon dogs immunized with the CAV2232C vaccine developed high mean VNA titers, while non-vaccinated raccoon dogs were antibody-negative. Conclusion: The CAV2232C vaccine is safe and induces a protective VNA titer in raccoon dogs. [ABSTRACT FROM AUTHOR]

Background: Sarcocystis includes a global group of apicomplexan parasites with two-host life cycle frequently circulating in wildlife and domestic hosts, including humans. Two of the most important wild terrestrial carnivores acting as definitive hosts are the red fox and raccoon dog, due to their wide distribution in Europe and usage of wild and farmed animals as prey. This study was conducted to determine the prevalence of Sarcocystis in hunted red foxes and raccoon dogs from nine regions of the Czech Republic and to identify isolated sporocysts by molecular techniques. Methods: Approximately 5 g of the contents of large intestine from 200 animals (197 red foxes and three raccoon dogs) were examined by flotation centrifugation coprological method. Only samples of 50 red foxes and one raccoon dog positive to Sarcocystis spp. were used for the nested PCR (nPCR) method to amplify a fragment or partial sequence on the cox1 gene. Ten species-specific primer pairs for detection of Sarcocystis spp. using farm animals as intermediate hosts were utilized. Results: In total, 38.1% of the red foxes and 66.7% of the raccoon dogs were positive to Sarcocystis by light microscopy. The molecular characterization resulted in the identification of five species in the red fox: S. arieticanis, S. capracanis, S. cruzi, S. miescheriana, and S. tenella, while the PCR was negative for the sole raccoon dog. The highest intraspecific variation was found for S. miescheriana, while S. tenella was the most prevalent. Co-infections occurred in the large intestine of the red fox. No zoonotic species were found in our samples. Conclusion: This is the first study where the potential role of the red fox and raccoon dogs as spreaders of Sarcocystis to farm animals in the Czech Republic is shown. The use of species-specific primers provides a fast and easy method for screening multiple samples for a particular Sarcocystis species. [ABSTRACT FROM AUTHOR]

In this study, we investigated faecal specimens from legally hunted and road‐killed red foxes, raccoons, raccoon dogs, badgers and martens in Germany for parasites and selected zoonotic bacteria. We found that Baylisascaris procyonis, a zoonotic parasite of raccoons, had spread to northeastern Germany, an area previously presumed to be free of this parasite. We detected various pathogenic bacterial species from the genera Listeria, Clostridium (including baratii), Yersinia and Salmonella, which were analysed using whole‐genome sequencing. One isolate of Yersinia enterocolitica contained a virulence plasmid. The Salmonella Cholerasuis isolate encoded an aminoglycoside resistance gene and a parC point mutation, conferring resistance to ciprofloxacin. We also found tetracycline resistance genes in Paeniclostridium sordellii and Clostridium baratii. Phylogenetic analyses revealed that the isolates were polyclonal, indicating the absence of specific wildlife‐adapted clones. Predators, which scavenge from various sources including human settlements, acquire and spread zoonotic pathogens. Therefore, their role should not be overlooked in the One Health context. [ABSTRACT FROM AUTHOR]

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Simple Summary: This study shows that automated computer vision techniques are highly effective when used to analyze images and to extract valuable information from them. We trained an algorithm with a set of 1600 images obtained from a study where wildlife approaching wild boar carcasses were monitored. This enabled the model to detect different classes of animals automatically in their natural environment with a mean average precision of 98.11%. Camera traps are becoming widely used for wildlife monitoring and management. However, manual analysis of the resulting image sets is labor-intensive, time-consuming and costly. This study shows that automated computer vision techniques can be extremely helpful in this regard, as they can rapidly and automatically extract valuable information from the images. Specific training with a set of 1600 images obtained from a study where wild animals approaching wild boar carcasses were monitored enabled the model to detect five different classes of animals automatically in their natural environment with a mean average precision of 98.11%, namely 'wild boar', 'fox', 'raccoon dog', 'deer' and 'bird'. In addition, sequences of images were automatically analyzed and the number of wild boar visits and respective group sizes were determined. This study may help to improve and speed up the monitoring of the potential spread of African swine fever virus in areas where wild boar are affected. [ABSTRACT FROM AUTHOR]

Since the COVID-19 outbreak, raccoon dogs have been suggested as a potential intermediary in transmitting SARS-CoV-2 to humans. To understand their role in the COVID-19 pandemic and the species barrier for SARS-CoV-2 transmission to humans, we analyzed how their ACE2 protein interacts with SARS-CoV-2 spike protein. Biochemical data showed that raccoon dog ACE2 is an effective receptor for SARS-CoV-2 spike protein, though not as effective as human ACE2. Structural comparisons highlighted differences in the virus-binding residues of raccoon dog ACE2 compared to human ACE2 (L24Q, Y34H, E38D, T82M, R353K), explaining their varied effectiveness as receptors for SARS-CoV-2. These variations contribute to the species barrier that exists between raccoon dogs and humans regarding SARS-CoV-2 transmission. Identifying these barriers can help assess the susceptibility of other mammals to SARS-CoV-2. Our research underscores the potential of raccoon dogs as SARS-CoV-2 carriers and identifies molecular barriers that affect the virus's ability to jump between species. Author summary: Raccoon dogs are thought to have been a crucial link in the chain that led to the spread of the COVID-19 virus to humans. The key to a coronavirus moving from one species to another is its spike protein's ability to bind to receptors on the cells of the new host. In our research, we investigated the interaction between the spike protein of the COVID-19 virus and the ACE2 receptor in raccoon dogs, using both structural and biochemical techniques. We found that the ACE2 receptor in raccoon dogs does indeed work as an effective receptor for the virus, but there are critical differences when compared to the human ACE2 receptor, which may act as barriers to the virus making the jump between raccoon dogs and humans. To our knowledge, this study is the first in-depth examination of these cross-species transmission barriers for the COVID-19 virus, shedding light on how other mammals might be impacted by the virus. Our findings indicate that raccoon dogs could potentially carry and pass the COVID-19 virus on to humans, providing foundational knowledge for how the virus can navigate between different species. [ABSTRACT FROM AUTHOR]

The western population of the red‐crowned crane Grus japonensis in mainland China has been decreasing in the past few decades and wild population enhancement programmes have been launched in this country. First, 14 captive‐bred red‐crowned cranes were released into the core area of Yancheng National Nature Reserve for Rare Birds (YNNR), one of the most important wintering areas of this species, in 2013 (seven individuals) and 2015 (seven individuals) and then 8 more captive‐bred cranes were released into YNNR from February 2022 to February 2023. We used satellite positioning and drone monitoring to study the status of released cranes. The results showed that two individuals (No. BJZ001 and BJZ008) from the first group of released cranes were found breeding in 6 of 7 years in the YNNR from 2017 to 2023. Three individuals (No. WNNR022, WNNR025 and WNNR026) from the second group of released cranes were recorded breeding in YNNR in 2023. All released cranes lived in the YNNR year round and did not migrate with wild cranes. Raccoon dogs, Nyctereutes procyonoides, were first recorded as red‐crowned crane nest predators in the YNNR. Although these released cranes breed successfully in the YNNR, nestlings might face the threat of predators in non‐traditional breeding areas. Further research is needed to determine whether offsprings of released individuals migrate with wild cranes and if breeding in their original wintering grounds is truly beneficial for population growth. [ABSTRACT FROM AUTHOR]

Many different animal species are susceptible to SARS-CoV-2, including a few Canidae (domestic dog and raccoon dog). So far, only experimental evidence is available concerning SARS-CoV-2 infections in red foxes (Vulpes vulpes). This is the first report of SARS-CoV-2 RNA detection in a sample from a red fox. The RT-qPCR-positive fox was zoo-kept together with another fox and two bears in the Swiss Canton of Zurich. Combined material from a conjunctival and nasal swab collected for canine distemper virus diagnostics tested positive for SARS-CoV-2 RNA with Ct values of 36.9 (E gene assay) and 35.7 (RdRp gene assay). The sample was analysed for SARS-CoV-2 within a research project testing residual routine diagnostic samples from different animal species submitted between spring 2020 and December 2022 to improve knowledge on SARS-CoV-2 infections within different animal species and investigate their potential role in a One Health context. Within this project, 246 samples from 153 different animals from Swiss zoos and other wild animal species all tested SARS-CoV-2 RT-qPCR and/or serologically negative so far, except for the reported fox. The source of SARS-CoV-2 in the fox is unknown. The fox disappeared within the naturally structured enclosure, and the cadaver was not found. No further control measures were undertaken. [ABSTRACT FROM AUTHOR]

Background: Aortic arch (AA) branching patterns vary among different mammalian species. Most previous studies have focused on dogs, whereas those on raccoon dogs remain unexplored. Objectives: The objective of this study was to describe the AA branching pattern in raccoon dogs and compare their morphological features with those of other carnivores. Methods: We prepared silicone cast specimens from a total of 36 raccoon dog carcasses via retrograde injection through the abdominal aorta. The brachiocephalic trunk (BCT) branching patterns were classified based on the relationship between the left and right common carotid arteries. The subclavian artery (SB) branching pattern was examined based on the order of the four major branches: the vertebral artery (VT), costocervical trunk (CCT), superficial cervical artery (SC), and internal thoracic artery (IT). Results: In most cases (88.6%), the BCT branched off from the left common carotid artery and terminated in the right common carotid and right subclavian arteries. In the remaining cases (11.4%), the BCT formed a bicarotid trunk. The SB exhibited various branching patterns, with 26 observed types. Based on the branching order of the four major branches, we identified the main branching pattern, in which the VT branched first (98.6%), the CCT branched second (81.9%), the SC branched third (62.5%), and the IT branched fourth (52.8%). Conclusions: The AA branching pattern in raccoon dogs exhibited various branching patterns with both similarities and differences compared to other carnivores. [ABSTRACT FROM AUTHOR]

Raccoon dogs (Nyctereutes procyonoides) and raccoons (Procyon lotor) are invasive alien species originating from East Asia and North America, respectively. They are discussed as vectors and reservoirs for various infectious diseases, including vector-borne and zoonotic pathogens, and are therefore a potential threat to human and domestic animal health, as well as to biodiversity and conservation. In the years 2021 and 2022, 110 raccoon dogs (Nyctereutes procyonoides) and 30 raccoons (Procyon lotor) were screened via qPCR for the presence of Leptospira spp., Rickettsia spp. and Borreliella spp. in the German federal state of Schleswig-Holstein as part of a health and risk assessment study. Borreliella spp. were confirmed in one raccoon dog and one raccoon, identified as Borreliella afzelii in the raccoon. Leptospira spp. were found in 21 (19.44%) raccoon dogs and 2 (6.90%) raccoons. In five raccoon dogs, Leptospira spp. were identified as Leptospira borgpetersenii, Leptospira kirschneri and Leptospira interrogans. [ABSTRACT FROM AUTHOR]

The intracellular protozoan Toxoplasma gondii is distributed worldwide and infects many species of warm-blooded animals. Most mammals, including humans, can serve as intermediate hosts. This pathogen, with its zoonotic potential, causes toxoplasmosis, a condition that can range from subclinical to fatal in humans. It is therefore important to assess the occurrence of the pathogen, even if only indirectly through the detection of antibodies. Epidemiological data on the seroprevalence in wild animals, including invasive species, are rare in Poland. Therefore, we tested 197 wild raccoons (Procyon lotor) and 89 raccoon dogs (Nyctereutes procyonoides) from Zgorzelec County, southwestern Poland, for the presence of antibodies. Samples were collected between January 2019 and December 2020 and analysed using a commercial indirect modified agglutination test (MAT, cut-off 1:25). The statistical analysis revealed significant differences in seroprevalence between the two predatory species. Of the 197 surveyed raccoons, 96 (48.73%; 95% confidence interval (CI): 41.73–55.73%) tested positive, while 25 of the 89 raccoon dogs (28.09%; 95% CI: 18.70–37.48%) were positive. Regarding risk factors, body weight and sex influenced the presence of T. gondii antibodies in both the species, with a higher likelihood of seropositivity among heavier animals and females, respectively. For raccoon dogs, juveniles were more likely to be seropositive than adults at a given weight. Our results suggest that T. gondii infection is widespread in the regional raccoon and raccoon dog populations, indicating a high level of parasite circulation in the environment. [ABSTRACT FROM AUTHOR]

BackgroundSarcocystis includes a global group of apicomplexan parasites with two-host life cycle frequently circulating in wildlife and domestic hosts, including humans. Two of the most important wild terrestrial carnivores acting as definitive hosts are the red fox and raccoon dog, due to their wide distribution in Europe and usage of wild and farmed animals as prey. This study was conducted to determine the prevalence of Sarcocystis in hunted red foxes and raccoon dogs from nine regions of the Czech Republic and to identify isolated sporocysts by molecular techniques.MethodsApproximately 5 g of the contents of large intestine from 200 animals (197 red foxes and three raccoon dogs) were examined by flotation centrifugation coprological method. Only samples of 50 red foxes and one raccoon dog positive to Sarcocystis spp. were used for the nested PCR (nPCR) method to amplify a fragment or partial sequence on the cox1 gene. Ten species-specific primer pairs for detection of Sarcocystis spp. using farm animals as intermediate hosts were utilized.ResultsIn total, 38.1% of the red foxes and 66.7% of the raccoon dogs were positive to Sarcocystis by light microscopy. The molecular characterization resulted in the identification of five species in the red fox: S. arieticanis, S. capracanis, S. cruzi, S. miescheriana, and S. tenella, while the PCR was negative for the sole raccoon dog. The highest intraspecific variation was found for S. miescheriana, while S. tenella was the most prevalent. Co-infections occurred in the large intestine of the red fox. No zoonotic species were found in our samples.ConclusionThis is the first study where the potential role of the red fox and raccoon dogs as spreaders of Sarcocystis to farm animals in the Czech Republic is shown. The use of species-specific primers provides a fast and easy method for screening multiple samples for a particular Sarcocystis species.