Isolation and Identification of Three Parvovirus Strains in Raccoon Dogs From Liaoning Province, China

To understand the epidemiological status of parvovirus (RDPV) in raccoon dogs, intestinal tissues of raccoon dogs in Liaoning Province of China were collected and evaluated. Three strains of raccoon dog parvovirus were successfully isolated from 12 intestinal tissues. Nine samples were positive for RDPV, with a positive rate of 75%. The VP2 and NS1 genes of the viruses were cloned and subjected to sequencing for analysis. The nucleotide sequences of the VP2 gene showed 99.94% similarity to the CPV-2a/Racoon dog/QHD/2/19(MT183665) strain, and the nucleotide sequences of the NS1 gene showed 99.75% similarity to RDPV-DP1 NS1(MF996335) strain. The three isolates belonging to the CPV-2a cluster were further confirmed by amino acid sequence alignment and phylogenetic analysis. Our study enriched the epidemiological data of parvovirus in raccoon dogs in the investigating region, and the results will be helpful for future investigation of the variations and transmission of raccoon dog parvoviruses.

Cryptocotyle lata (Trematoda: Heterophyidae) Adult from a Korean Raccoon Dog, Nyctereutes procyonoides koreensis

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.

ECOLOGICAL ASPECTS OF MORPHOGENESIS OF CONNECTIVE TISSUE COMPONENTS OF THE PANCREAS OF A RACCOON DOG IN POSTNATAL ONTOGENESIS OF THE RADIATION FACTOR

There have been no studies devoted to the study of the pancreas of a raccoon dog living in a contaminated area in the world. Therefore, the aim of our research was to study the connective tissue components of the pancreas in a raccoon dog at different stages of postnatal ontogenesis. The material for the study was raccoon dogs seized from former settlements, in the vicinity of lakes Zhartai, Vyura, Gnezdnoye and the Nesvich River in the exclusion zone (30 – kilometer exclusion zone of the Chernobyl nuclear power plant). As a result of the studies, the features of the morphofunctional state of the pancreatic stroma under the influence of the radiation factor were revealed.

Changes in the occurrence range of hosts cause the expansion of the ornate dog tick Dermacentor reticulatus (Fabricius, 1794) in Poland

The turn of the twentieth and twenty-first centuries brought changes in the range of many pathogens and their vectors. An example is the Dermacentor reticulatus tick. So far, relatively not numerous, their range of occurrence was divided into two areas—western European and eastern. An increase in the number and spread of this tick has been observed since the 1990s. Possible causes may be changes in the average summer and winter temperature in Europe and changes in the structure and use of agricultural land and forest areas. Changes in the distribution and abundance of mammals which are the main hosts of adult ticks, such as elk Alces alces, red deer Cervus elaphus, raccoon dog Nyctereutes procyonoides and the red fox Vulpes vulpes, may be important factors as well. Increase in the size of the hosts populations correlates with the subsequent increase in numbers and the emergence of new tick populations. The food base of adult ornate dog ticks is a large herbivorous mammal population. Predatory mammals can support the expansion of the ticks. The expansion of the raccoon dog in the west correlates with the emergence of new D. reticulatus populations west to the previous border of the eastern range of their occurrence. The intrusion of foxes into inhabited areas may be a synanthropic factor that supports the rise of new tick populations in urban agglomerations.

Species- and age-dependent distribution of retinol and α-tocopherol in the Canidae family during the cold season

Vitamins A and E are known as nutrients involved in metabolic processes and facilitating the adaptation of animals. The metabolism of these vitamins is closely related to lipid metabolism, which has seasonal variations in animals inhabiting northern latitudes. The aim of this study was to investigate the concentrations of retinol (vitamin A) and α-tocopherol (vitamin E) in the cold season (October to February) in tissues of Canidae species that have different ecological characteristics: the blue fox (Vulpes syn. Alopex lagopus), silver fox (Vulpes vulpes), their interspecific hybrids (Vulpes×Vulpes), raccoon dog (Nyctereutes procyonoides), and grey wolf (Canis lupus). In addition, age-related differences in the levels of these vitamins were determined. Results showed the distribution of retinol and α-tocopherol in the body of the canids was similar, with larger amounts being found in the liver and kidney cortex, which play a regulatory role in the metabolism of these nutrients. The higher retinol level in the liver of wolves and interspecific hybrids of blue fox and silver fox, as compared to the retinol level in the liver of other species, might be species-specific and could also be attributed to dietary differences. The blue fox and raccoon dog both have a higher capacity for α-tocopherol accumulation in the cold season, apparently due to their ability to store substantial fat reserves. Retinol and α-tocopherol levels were generally higher in the tissues of mature animals.

Roadkills as a Method to Monitor Raccoon Dog Populations

The raccoon dog (Nyctereutes procyonoides) is one of the most frequently killed species on Lithuanian roads. As an invasive species, up-to-date knowledge of population size, trends and spatial distribution is critically important both for species assessment and for the planning of control measures. In Lithuania, however, raccoon dog surveys have not been carried out since 1997. We investigated, therefore, whether roadkill counts on predefined routes could be used as a proxy for a survey. Our dataset includes survey numbers for the period 1956–1997, hunting bag sizes for 1965–2020 (including the spatial distribution of the hunting bag in 2018–2020) and roadkill data relating to 1551 individuals between 2002–2020. At the most local scale, that of the hunting areas of hunting clubs, correlations between the numbers of hunted and roadkilled individuals were negative and insignificant or absent. At the country scale, however, we found significant correlation both between the numbers surveyed and hunted in 1965–1997 (r = 0.88), and between those hunted and the number of roadkills in 2002–2020 (r = 0.56–0.69). Therefore, we consider that roadkill counts on predefined and stable routes may be used as a proxy for a survey at the country scale. Practical implementation of the method is proposed.

Leptospiral meningoencephalitis in a raccoon dog

Neuroleptospirosis is a rare disease caused by pathogenic Leptospira interrogans in humans; however, it has not been fully studied in animals. A young wild raccoon dog was found convulsing in the recumbent position and died the next day. Histologic examination revealed nonsuppurative meningoencephalitis in the cerebrum, cerebellum, midbrain, and medulla oblongata. The lesions consisted of mixed infiltrates of Iba1-positive macrophages and CD3-positive T cells, with a small number of CD79α-positive B cells and myeloperoxidase-positive neutrophils. In the frontal cortex, perivascular cuffs and adjacent microglial nodules were distributed diffusely, especially in the molecular layer. Glial nodules were comprised of Iba1- and myeloperoxidase-positive activated microglia. Immunohistochemistry revealed leptospires in mononuclear cell perivascular cuffs, but not in glial nodules. Neuroleptospirosis was accompanied by Leptospira-related nonsuppurative interstitial nephritis, pulmonary edema and hemorrhage, and coronary periarteritis, as well as Toxocara tanuki in the small intestine and nonspecific foreign-body granulomas in the lungs and stomach.

Tibial Tuberosity Transposition Fixation with a Locking Plate during Medial Patellar Luxation Surgery: An Ex Vivo Mechanical Study

Objectives The purpose of this study was to compare the load at failure, stiffness and mode of failure between three types of tibial tuberosity transposition fixation techniques: (a) pin and figure-8 tension band wire (Pin-TBW), (b) locking plate with pin and a tension band wire (Plate-Pin-TBW) and (c) locking plate with a pin (Plate-Pin). Methods Six pairs of raccoon dog cadaveric tibiae were tested in Phase I Pin-TBW versus Plate-Pin-TBW and seven pairs in Phase II Plate-Pin-TBW versus Plate-Pin. One limb of each pair was randomly assigned to one of two groups for each phase. A tensile force was applied to the patellar ligament until construct failure. Results Pin-TBW (342N ± 54.7N) failed at a lower load than Plate-Pin-TBW (469N ± 77.3N), p = 0.00748, with all Pin-TBW failing by fracture and the majority of Plate-Pin-TBW failing by rupture of patellar ligament. Pin-TBW group Phase I, normalized with Plate-Pin-TBW Phase I, failed at a lower load than Plate-Pin group Phase II, normalized with Plate-Pin-TBW Phase II, p = 0.00467. There was no significant difference in mean load at failure, stiffness or mode at failure between the groups in the Phase II study. Clinical Significance Although ex vivo mechanical testing does not replicate the postoperative live dog or cat, these results demonstrate lower construct strength of the Pin-TBW construct compared with the Plate-Pin construct in the raccoon dog cadaver model.

Role of Brown and Beige Adipose Tissues in Seasonal Adaptation in the Raccoon Dog (Nyctereutes procyonoides)

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.