Project description:Total 513 heterophyid flukes were collected from a carcass of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. With morphological and molecular characteristics, the flukes were identified to Cryptocotyle lata. The adult C. lata were minute, transparent, pentagonal, 522 µm long by 425 µm wide. Ceca extended into post-testicular region. Ventrogenital sac elliptical, 79 µm by 87 µm with genital pore and ventral sucker. Two testes semielliptical and slightly lobed, located in the posterior region, right testis 173 µm by 155 µm, left testis 130 µm by 134 µm. In a phylogenetic tree, the fluke specimen of this study was grouped with C. lata divergent from Cryptocotyle lingua. We report here N. procyonoides koreensis first as a natural definitive host of C. lata.
Project description:Present study was performed to describe the morphological and molecular characterization of Toxocara tanuki (Nematoda: Ascaridae) from Korean raccoon dog, Nyctereutes procyonoides koreensis, naturally infected in the Republic of Korea (Korea). Juvenile and adult worms of T. tanuki were recovered in 5 out of 10 raccoon dogs examined and the larval worms were detected in 15 out of 20 muscle samples (75%). Small lateral alae were observed on the cranial end of the body in male and female adults and 2 long spicules (3.0-3.5 mm) were characteristically observed in the posterior end of males. In SEM observation, 18 pairs of proximal precloacal, a precloacal median, a postcloacal median and 5 pairs of postcloacal papillae were uniquely revealed in the posterior portion of males, but the proximal papillae were not shown in the lateral ends of females. Molecular analysis on the 18S rRNA partial DNA sequences was revealed the same finding in both samples, adult worms and muscle larvae, which are closely related to T. tanuki. In conclusion, it was confirmed for the first time that T. tanuki is indigenously distributed, the Korean raccoon dog is acted as the natural definitive host of this nematode in Korea and the morphological characteristics of T. tanuki were shown in specific structure for single postcloacal median papilla in male.
Project description:Brown adipose tissue (BAT) expresses uncoupling protein-1 (UCP1), which enables energy to be exerted towards needed thermogenesis. Beige adipocytes are precursor cells interspersed among white adipose tissue (WAT) that possess similar UCP1 activity and capacity for thermogenesis. The raccoon dog (Nyctereutes procyonoides) is a canid species that utilizes seasonal obesity to survive periods of food shortage in climate zones with cold winters. The potential to recruit a part of the abundant WAT storages as beige adipocytes for UCP1-dependent thermogenesis was investigated in vitro by treating raccoon dog adipocytes with different browning inducing factors. In vivo positron emission tomography/computed tomography (PET/CT) imaging with the glucose analog 18F-FDG showed that BAT was not detected in the adult raccoon dog during the winter season. In addition, UCP1 expression was not changed in response to chronic treatments with browning inducing factors in adipocyte cultures. Our results demonstrated that most likely the raccoon dog endures cold weather without the induction of BAT or recruitment of beige adipocytes for heat production. Its thick fur coat, insulating fat, and muscle shivering seem to provide the adequate heat needed for surviving the winter.
Project description:BackgroundApicomplexan parasites of the genus Sarcocystis have an obligate two-host life-cycle and comprise about 200 species, which infect different cold- and warm-blooded hosts, including humans. Recently, morphological and molecular studies of sarcocysts in broadly spread carnivore hosts have been on the rise. The description of muscular tissues infection by Sarcocystis in the raccoon dog and the common raccoon from the Czech Republic is herein presented.MethodsDuring January-August 2019, 15 raccoon dogs and 1 common raccoon were examined from 5 districts (Česká Lípa, Liberec, Mladá Boleslav, Trutnov and Ústí nad Labem) of the Czech Republic. Muscle parts (diaphragm, forearm, hind-limb, tongue and heart) were examined in wet preparations under compression by light microscopy. After finding Sarcocystis sp., morphological characteristics and molecular analyses of 18S rRNA, 28S rRNA, ITS1 and cox1 loci were used to identify the species.ResultsSarcocysts were detected and identified in 1 out of 15 raccoon dogs and in the single common raccoon. Preferential infection sites were diaphragm and tongue, followed by forearm and hind limb. To our knowledge, this is the first identification of microscopic sarcocysts by multi-locus genetic analysis from both host species. Molecular analyses revealed 100% similarity at 18S rRNA, 28S rRNA, and cox1 genes with S. lutrae for both hosts and 98-100% identity at the ITS1 region of the isolate from the common raccoon.ConclusionsBoth widely distributed non-indigenous wild carnivores represent new intermediate host records for S. lutrae and the first report of this parasite in a member of the family Procyonidae, but still with an unknown natural definitive host. Molecular data revealed that this parasite species appears more closely related to the Sarcocystis spp. using raptorial birds as definitive hosts. Therefore, further studies aimed at its identification, including the complete life-cycle, remain necessary.
Project description:The neozoan species raccoon dog (Nyctereutes procyonoides) and raccoon (Procyon lotor) are widespread in Europe and potential vectors of many diseases that can threaten human and domestic animal health. Facing a further spread of these species, it is important to know about (i) pathogens imported and/or (ii) pathogens acquired in the new habitat. Thus, we investigated the parasite fauna of wild raccoon dogs and raccoons from Austria, at the edge of their new distribution range. The eight examined raccoons were nearly free of pathogens including Baylisascaris procyonis, and thus assumed to have a low epidemiological impact, so far. Out of ten raccoon dog specimens, we found one from western Austria to be infected with Echinococcus multilocularis and another three from the eastern wetland regions to harbour adults of Alaria alata. Furthermore, we detected Babesia cf. microti in five of eight raccoon dogs all over Austria but none of our samples were tested positive for Trichinella spp. Nevertheless, the raccoon dog seems to be a relevant host, at least for the zoonotic pathogens E. multilocularis and A. alata, and we suggest to further monitor the raccoon dogs parasite fauna.
Project description:The definitive hosts of Metagonimus hakubaensis are reported to be hamsters, rats, mice, dogs, cats, chickens, and quails in experimental infection and Japanese water shrews in natural infection. Here we report that raccoon dogs are new natural definitive hosts of M. hakubaensis, based on morphological and molecular analyses of Metagonimus flukes collected from the host species from Aomori Prefecture, Japan. Moreover, M. hakubaensis recovered from raccoon dogs showed higher fecundity than those recovered from Japanese water shrews. Therefore, raccoon dogs were considered as a more suitable natural definitive host of M. hakubaensis than Japanese water shrews.
Project description:The extent of gene flow during the range expansion of non-native species influences the amount of genetic diversity retained in expanding populations. Here, we analyse the population genetic structure of the raccoon dog (Nyctereutes procyonoides) in north-eastern and central Europe. This invasive species is of management concern because it is highly susceptible to fox rabies and an important secondary host of the virus. We hypothesized that the large number of introduced animals and the species' dispersal capabilities led to high population connectivity and maintenance of genetic diversity throughout the invaded range. We genotyped 332 tissue samples from seven European countries using 16 microsatellite loci. Different algorithms identified three genetic clusters corresponding to Finland, Denmark and a large 'central' population that reached from introduction areas in western Russia to northern Germany. Cluster assignments provided evidence of long-distance dispersal. The results of an Approximate Bayesian Computation analysis supported a scenario of equal effective population sizes among different pre-defined populations in the large central cluster. Our results are in line with strong gene flow and secondary admixture between neighbouring demes leading to reduced genetic structuring, probably a result of its fairly rapid population expansion after introduction. The results presented here are remarkable in the sense that we identified a homogenous genetic cluster inhabiting an area stretching over more than 1500km. They are also relevant for disease management, as in the event of a significant rabies outbreak, there is a great risk of a rapid virus spread among raccoon dog populations.
Project description:Although kinship (parent-offspring or siblings) contact has been suggested as a driving factor for sarcoptic mange epizootic in raccoon dogs (Nyctereutes procyonoides), no effect has been reported. In contrast, habitat fragmentation caused by urbanization may result in a high occurrence of sarcoptic mange, because habitat fragmentation may promote contact infection by increasing the population density of raccoon dogs. The habitat distribution of raccoon dogs may therefore influence epizootic sarcoptic mange. The genetic relationship between raccoon dogs was analyzed to examine Sarcoptes scabiei transmission between kin. The relationship between S. scabiei infection and the habitat of raccoon dogs was also investigated. Seventy-five raccoon dogs from Takasaki, Gunma prefecture, were examined from 2012 to 2018; 23 were infested with S. scabiei. The genotypes were determined using 17 microsatellite loci, and the relationships were categorized into four patterns by the ML-Relate software. There was no significant difference between infested pairs and other two pairs (Chi- squared test: ?2=0.034, df=1, P=0.85). Although it was difficult to predicate because the mortality rate was unclear in this study, kinship contact does not seem to be an important factor for sarcoptic mange epizootic. S. scabiei infection rates were significantly associated with the location of village sections (OR=1.55, 95% CI=1.11-2.17, P=0.011). It is suggested that direct/indirect contact between individuals living closely together is an important factor for the transmission of S. scabiei.
Project description:BACKGROUND:The abuse of antibiotics in animal husbandry imposes a serious threat to both animal health and the environment. As a replacement for antibiotics, probiotic products have been widely used in livestock farming to promote growth of animals. However, no products specifically developed for farmed raccoon dogs and foxes are commercially available at the moment. This study was conducted to investigate the effects of mixed probiotics on farmed raccoon dogs and foxes. RESULTS:Two feeding trials on farmed raccoon dogs and foxes were performed. A mixed probiotic preparation composed of Bifidobacterium bifidum, Clostridium butyricum, Bacillus subtilis and Bacillus licheniformis was fed to these two canine species in order to assess whether such a mixed probiotics can be an alternative to antibiotics (control group). The body weight of raccoon dogs exhibited an increasing tendency with mixed probiotics administration, while that of foxes did not. The serum antioxidant activity was evaluated, and a significantly increase of total antioxidative capacity (T-AOC) was observed in both species. Illumina MiSeq was used for the sequencing of 16S rRNA genes to compare the composition of fecal microbiota between the control and mixed probiotics groups. Although ?-diversity did not change, ?-diversity of the fecal microbiota showed a distinct dissimilarity between the control and probiotics groups of both raccoon dogs and foxes. Dietary mixed probiotics increased the abundance of the genus Bifidobacterium in the fecal samples of raccoon dogs, and the genus Bacillus in the fecal samples of foxes. The different responses of raccoon dogs and foxes to probiotics might be the result of differences in the composition of the native gut microbiota of the two species. CONCLUSIONS:The mixed probiotics preparation composed of Bifidobacterium bifidum, Clostridium butyricum, Bacillus subtilis and Bacillus licheniformis could be an effective feed additive for the improvement of the health of farmed raccoon dogs, but it may not be suitable for foxes.
Project description:Anaplasmosis, cat-scratch disease, and Lyme disease are emerging vector-borne infectious diseases in Korea. Although the prevalence of vector-borne pathogens (VBPs) in domestic animals and vector arthropods has been documented, there is limited information on the presence of VBPs in wild animals. The raccoon dog (Nyctereutes procyonoides), a wild canid found in East Asia and Europe, represents a potential wildlife reservoir for zoonotic diseases. To investigate the prevalence of VBPs in raccoon dogs, 142 carcasses and 51 blood samples from captured raccoon dogs were collected from 2003 to 2010 and from 2008 to 2009, respectively, in Korea. In addition, 105 Haemaphysalis flava (14 larvae, 43 nymphs, 32 males, and 16 females) and nine Haemaphysalis longicornis (all female) were collected from three raccoon dogs. Samples of the spleen and blood were tested for the presence of VBPs by using nested polymerase chain reaction. Among the samples collected from 193 raccoon dogs and 114 ticks, two samples were positive for Anaplasma phagocytophilum, four for Anaplasma bovis, two for Borrelia theileri, and two for Bartonella henselae. To the best of our knowledge, this study is the largest survey of raccoon dogs aimed at the analysis of VBPs in this species. Moreover, the present study represents the first identification of A. phagocytophilum, B. henselae, and B. theileri in raccoon dogs in their native habitat (East Asia).