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Angiotensin converting enzyme 2 (ACE2) is a host cell membrane protein (receptor) that mediates the binding of coronavirus, most notably SARS coronaviruses in the respiratory and gastrointestinal tracts. Although SARS-CoV-2 infection is mainly confined to humans, there have been numerous incidents of spillback (reverse zoonoses) to domestic and captive animals. An absence of information on the spatial distribution of ACE2 in animal tissues limits our understanding of host species susceptibility. Here, we describe the distribution of ACE2 using immunohistochemistry (IHC) on histological sections derived from carnivores, ungulates, primates and chiroptera. Comparison of mink (Neovison vison) and ferret (Mustela putorius furo) respiratory tracts showed substantial differences, demonstrating that ACE2 is present in the lower respiratory tract of mink but not ferrets. The presence of ACE2 in the respiratory tract in some species was much more restricted as indicated by limited immunolabelling in the nasal turbinate, trachea and lungs of cats (Felis catus) and only the nasal turbinate in the golden Syrian hamster (Mesocricetus auratus). In the lungs of other species, ACE2 could be detected on the bronchiolar epithelium of the sheep (Ovis aries), cattle (Bos taurus), European badger (Meles meles), cheetah (Acinonyx jubatus), tiger and lion (Panthera spp.). In addition, ACE2 was present in the nasal mucosa epithelium of the serotine bat (Eptesicus serotinus) but not in pig (Sus scrofa domestica), cattle or sheep. In the intestine, ACE2 immunolabelling was seen on the microvillus of enterocytes (surface of intestine) across various taxa. These results provide anatomical evidence of ACE2expression in a number of species which will enable further understanding of host susceptibility and tissue tropism of ACE2 receptor-mediated viral infection

Parasites may negatively affect hosts condition, especially when infection intensity is high. Species introduced to a new habitat are often less exposed to a parasite pressure but may accumulate parasites in time. American mink (Neovison vison) introduced to Europe, Asia, and South America is an example of such invasive species. We analysed nematode prevalence and digestive tract infection intensity in 796 feral American mink from Poland. The analyses were performed separately for stomach, duodenum, small intestine and large intestine. Parasite species identification was performed using molecular methods based on highly conserved nuclear 18S rRNA gene and supplemented with morphological analysis. In total, we collected 26,852 nematodes and 98.6% of them were isolated from mink stomachs. We found positive association between infection intensity in stomach and other parts of digestive tract. Nematode prevalence was estimated at 63.8% and average infection intensity per one American mink at 52.9 (range from 1 to 1118). If the stomach results were theoretically and intentionally omitted the prevalence was 5 times lower (12.7%) and infection intensity 14 times lower (3.7; range 1–50). We identified two nematode species in digestive tracts of American mink: Aonchotheca putorii and Molineus patens. The 18S rRNA gene sequence of Molineus patens has been reported for the first time. The results showed that Aonchotheca putorii is a dominating nematode in the invasive American mink and that it inhabits stomach intensively and preferably.

Mink urinary tract disease (MUTD) often presents as urolithiasis and/or cystitis and is known as an important cause of mortality in mink kits during the early growth season. Antimicrobial flock treatment has been routinely applied as preventive/therapeutic protocol on Danish mink farms with increased mortality associated with MUTD. The therapeutic effect of this treatment strategy has not previously been investigated. In this study, we applied controlled parallel group treatment trials to assess the effect of sulfadiazine/trimethoprim and amoxicillin treatment on mortality associated with MUTD in mink kits. On farm A, eight mink kits were diagnosed with MUTD post mortem in the treatment group (n = 1920, sulfadiazine/trimethoprim treatment: 30 mg/kg, q 24 h, P.O for 5 days) compared to 16 in the untreated control group (n = 1920). No significant difference in mortality associated with MUTD were found between the treatment and the control group using the Fisher’s exact test (P = 0.15). Treatment group 2 (n = 1920, amoxicillin treatment: 14 mg/kg q 24 h, P.O for 5 days) and treatment group 3 (n = 2088, amoxicillin treatment: 7.5 mg/kg q 24 h, P.O for 5 days) were investigated on farm B. Eight and four mink kits were diagnosed with MUTD post mortem in group 2 and 3, respectively. No difference between occurrence of MUTD were found between the control group and treatment group 2 (P = 0.42) or treatment group 3 (P = 0.75). No significant difference between final body weights or weight gain were found between treatment and control weighing groups on farm A or B. In conclusion, antimicrobial treatment administered in the feed showed no significant effect on weight gain or mortality associated with MUTD on the farms included in this study.

The study was aimed to evaluate a possible effect of body condition of female farmed mink (Neovison vison) at the moment of conception on their prospective reproduction and behavior. 601 Perl mink females at age 1 and 2 years were assigned to one of five groups according to their body condition. The following parameters were analyzed: gestation and diapause lengths, litter size, live-born litter size, number of weaned per litter, female barrenness, and the incidence of fur-chewing. The effect of body condition was more pronounced in yearling females, where the largest litters, the highest number of live-born per litter, and the highest weaning success were found in the group with the ideal body condition. In both age groups, the shortest pregnancies and diapause periods were observed in the thinnest females. Fur-chewing was most often noticed in either the thinnest or the most obese animals; females of these groups also exhibited the highest rates of barrenness. Consequently, the lowest incidence of fur-chewing, female barrenness were found in females with ideal body condition.

American mink (Neovison vison) is a significant source of global fur production. Except for a few studies from Denmark and Canada reporting antimicrobial resistance in bacteria isolated from clinic...

Severe acute respiratory syndrome coronavirus 2 has caused a pandemic in humans. Farmed mink (Neovison vison) are also susceptible. In Denmark, this virus has spread rapidly among farmed mink, resulting in some respiratory disease. Full-length virus genome sequencing revealed novel virus variants in mink. These variants subsequently appeared within the local human community.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of coronavirus disease and has been spreading worldwide since December 2019. The virus can infect different animal species under experimental conditions, and mink on fur farms in Europe and other areas are susceptible to SARS-CoV-2 infection. We investigated SARS-CoV-2 infection in 91 mink from a farm in northern Poland. Using reverse transcription PCR, antigen detection, and next-generation sequencing, we confirmed that 15 animals were positive for SARS-CoV-2. We verified this finding by sequencing full viral genomes and confirmed a virus variant that has sporadic mutations through the full genome sequence in the spike protein (G75V and C1247F). We were unable to find other SARS-CoV-2 sequences simultaneously containing these 2 mutations. Country-scale monitoring by veterinary inspection should be implemented to detect SARS-CoV-2 in other mink farms.

Over 35 fur colours have been described in American mink (Neovison vison), only six of which have been previously linked to specific genes. Moyle fur colour belongs to a wide group of brownish colours that are highly similar to each other, which complicates selection and breeding procedures. We performed whole genome sequencing for two American minks with Moyle (m/m) and Violet (a/a m/m /p/p) phenotypes. We identified two frame-shift mutations in the gene encoding Ras-related protein-38 (RAB38), which regulates the trafficking of tyrosinase-containing vesicles to maturing melanosomes. The results highlight the role of RAB38 in the biogenesis of melanosomes and melanin and the genetic mechanism contributing to hair colour variety and intensity. These data are also useful for tracking economically valuable fur traits in mink breeding programmes.

Invasive non-native species can become reservoirs of zoonotic pathogens and cause their spread during colonization, increasing the risk of zoonoses transmission to both wild hosts and humans. American mink (Neovison vison) are considered an important invasive mammal species responsible for carrying endoparasites. The aim of our study was to evaluate the role of feral American mink as a possible transmission vector of Echinococcus spp. and Toxocara spp. in wildlife. We analysed the frequency of American mink exposure to both parasites, the spatial distribution in Poland, and the variability over time on the basis of specific antibody presence using ELISA and Western blot. Alimentary tract analyses revealed that American mink do not serve as definitive hosts for these parasites. Altogether, 1100 American mink were examined. The average seropositivity for American mink was 14.2% for echinococcosis and 21.7% for toxocarosis; dual-seropositivity was detected in only 6.0%. Seroprevalence of both parasites differed between study sites and significantly increased over time in Toxocara spp. Thus, our study revealed that free-living American mink are exposed to parasites and likely to be involved in the maintenance of both Echinococcus spp. and Toxocara spp. in the wild as paratenic hosts.

European and American minks (Mustela lutreola and Neovison vison, respectively) are very similar in their ecology, behavior, and morphology. However, the American mink is a generalist predator and seems to adapt better to anthropized environments, allowing it to outcompete the European mink in areas where it has been introduced, threatening the survival of the native species. To assess whether morphological differences may be contributing to the success of the American mink relative to the European mink, we analyzed shape variation in the cranium of both species using 3D geometric morphometrics. A set of 38 landmarks and 107 semilandmarks was used to study shape variation between and within species, and to assess how differences in size factored into that variation. Sexual dimorphism in both size and shape was also studied. Significant differences between species were found in cranial shape, but not in size. Relative to American mink, European mink have a shorter facial region with a rounder forehead and wider orbits, a longer neurocranium with less developed crests and processes, and an antero‐medially placed tympanic bullae with an anteriorly expanded cranial border. Within species, size‐related sexual dimorphism is highly significant, but sexual dimorphism in shape is only significant in American mink, not in European mink. Additionally, two trends common to both species were discovered, one related to allometric changes and another to sexual size dimorphism. Shape changes related to increasing size can be subdivided into two, probably related, groups: increased muscle force and growth. The first group somewhat parallels the differences between both mink species, while the second group of traits includes an anterodorsal expansion of the face, and the neurocranium shifting from a globous shape in small individuals to a dorsoventrally flattened ellipse in the largest ones. Finally, the sexual dimorphism trend, while also accounting for differences in muscle force, seems to be related to the observed dietary differences between males and females. Overall, differences between species and sexes, and shape changes with increasing size, seem to mainly relate to differences in masticatory‐muscle volume and therefore muscle force and bite force, which, in turn, relate to a wider range of potential prey (bigger prey, tougher shells). Thus, muscle force (and dietary range) would be larger in American mink than in European mink, in males than in females, and in larger individuals than in smaller ones., Cranial shape and size variation in European (Mlu) and American minks (Nvi) were studied. Both species differed in shape but not size, while sexes within each differed in size but in shape only for Nvi. Allometric shape changes were related to growth and sexual dimorphism. Overall, differences among species, sexes, and sizes related to masticatory‐muscle volume, which suggests that muscle force (and dietary range) would be larger in Nvi than in Mlu, in males than in females, and in larger mink.

Leishmania infantum produces an endemic disease in the Mediterranean Basin that affects humans and domestic and wild mammals, which can act as reservoir or minor host. In this study, we analyzed the presence of the parasite in wild American minks, an invasive species in Spain. We screened for L. infantum DNA by PCR using five primer pairs: Two targeting kinetoplast DNA (kDNA), and the rest targeting the ITS1 region, the small subunit of ribosomal RNA (SSU) and a repetitive sequence (Repeat region). The detection limit was determined for each method using a strain of L. infantum and a bone marrow sample from an infected dog. PCR approaches employing the Repeat region and kDNA (RV1/RV2 primers) showed higher sensitivity than the other PCR methods when control samples were employed. However, only PCR of the Repeat region and nested PCR of SSU (LnSSU) detected the parasite in the samples, while the other three were unable to do so. The majority of the analyzed animals (90.1%) tested positive. American mink may act as an incidental host of the disease for other mammals and should be further investigated, not only for their negative impact on the local fauna, but also as carriers of zoonotic diseases.

Genetic testing using STR sequences is a fundamental element of investigative and judicial activities in various types of cases involving animals, such as theft of animals or products derived from ...

Pre-weaning diarrhea in mink kits (PWD), also known as “sticky kits” is a multifactorial syndrome of considerable concern in the mink production. Evidence based treatment protocols are not available, and treatment is therefore empirical and often based on the use of antimicrobials. The purpose of the study was to test the effect of 3 alternative treatments to a standard antibiotic treatment, to characterize the study groups microbiologically, and finally to compare the intestinal microbiota of the different treatment groups at the age of 42 days. In total, 226 one to three week old mink kits with PWD from 36 litters were treated with either 1) Lactobacillus reuteri, 2) benzylpenicillin, 3) Ringer lactate or 4) amoxicillin (controls). Effects of the treatments were measured as weight gain from day 0 to day 15 and mortality. Multivariable linear mixed model regression showed no significant difference in weight gain between probiotic-, penicillin or fluid-treated mink kits and the amoxicillin treated controls. There was also no significant difference in mortality risk between the treatment groups. Bacterial culture and next generation sequencing of the viral contents showed that the study groups were uniform with a high frequency of Staphylococcus intermedius group (SIG) bacteria, Escherichia coli, Enterococcus hirae, Mamastrovirus and Sapovirus which were representative for mink kits with PWD. 16S sequencing results of the bacterial microbiota, when the kits were 42 days old were dominated by clostridia in all groups and showed no clear differences in the bacterial composition between the different treatment groups.

Introduction: Canine roundworm T. canis and T. leonina infections were investigated in experimentally infected farm mink (Neovison vison) to describe the pattern of pathological lesions in this paratenic host. Material and Methods: Infections in mink developed following ingestion of embryonated eggs of either parasite or mice tissue infected with both parasite species. Results: Comparative analysis of haematoxylin- and eosin-stained slides showed essential differences among the experimental groups. The lesions observed included eosinophil and mononuclear inflammatory infiltrates of the intestinal wall and local lymph nodes, inflammation and haemorrhages in liver tissues, and interstitial inflammation and mineralisation of the kidneys and lungs. Larvae migrating through the minks’ bodies also caused particularly salient enlargement of lymphoid follicles in the spleen and inflammatory infiltrates of mononuclear cells in skeletal and heart muscles. Conclusions: It is assumed that histopathological lesions appeared as a local and general host response to invasive L3 T. canis and T. leonina larvae migrating through the tissues of infected farm mink. Interestingly, mink infected with embryonated eggs had more pronounced lesions than animals infected with tissue larvae. Detailed histopathological examinations of parenchymal organs and striated muscles revealed lesions resembling those observed in other paratenic host species due to toxocarosis.

Study into the effect of vitamins A and E on total and differential leukocyte count, as well as morphometric parameters of lymphocytes in three carnivorous species—dark brown American mink (Neovison vison, Mustelidae), blue fox (Vulpes lagopus, Canidae), and silver fox (V. vulpes, Canidae)—was conducted. The highest white blood cells count (WBC count) and the largest surface area of lymphocytes and their nuclei in the peripheral blood were observed in mink, while the lowest indices were found in silver fox. Additional supplementation with vitamins A and E for 14 days had no effect on the WBC and differential leukocyte count, except for silver foxes receiving vitamin E, in which a decrease in relative eosinophils and monocytes content was observed. The action of vitamins was mainly manifested in changes in the lymphocytes’ morphometric parameters. The addition of vitamin A into the diet of mink and silver fox and vitamin E into only mink’s diet led to an increase in the surface area of lymphocytes and, in some cases, their nuclei, which was accompanied by a rise in the cytoplasm size in mink cells. In blue fox, on the contrary, both vitamins induced a decrease in the surface area of the lymphocytes and their nuclei. The observed changes may be associated with the immunomodulatory effects of vitamins A and E of the studied species of carnivorous mammals, while the found differences may be associated with features of the morphologic and functional organization of lymphocytes and the immune status.

The breadth of animal hosts that are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and may serve as reservoirs for continued viral transmission are not known entirely. In August 2020, an outbreak of SARS-CoV-2 occurred in multiple mink farms in Utah and was associated with high mink mortality and rapid viral transmission between animals. The outbreak’s epidemiology, pathology, molecular characterization, and tissue distribution of virus within infected mink is provided. Infection of mink was likely by reverse zoonosis. Once established, infection spread rapidly between independently housed animals and farms, and caused severe respiratory disease and death. Clinical signs were most notably sudden death, anorexia, and increased respiratory effort. Gross pathology examination revealed severe pulmonary congestion and edema. Microscopically there was pulmonary edema with moderate vasculitis, perivasculitis, and fibrinous interstitial pneumonia. Reverse transcriptase polymerase chain reaction (RT-PCR) of tissues collected at necropsy demonstrated the presence of SARS-CoV-2 viral RNA in multiple organs including nasal turbinates, lung, tracheobronchial lymph node, epithelial surfaces, and others. Whole genome sequencing from multiple mink was consistent with published SARS-CoV-2 genomes with few polymorphisms. The Utah mink SARS-CoV-2 strain fell into Clade GH, which is unique among mink and other animal strains sequenced to date and did not share other spike RBD mutations Y453F and F486L found in mink. Localization of viral RNA by in situ hybridization revealed a more localized infection, particularly of the upper respiratory tract. Mink in the outbreak reported herein had high levels of virus in the upper respiratory tract associated with mink-to-mink transmission in a confined housing environment and were particularly susceptible to disease and death due to SARS-CoV-2 infection.Author SummaryThe recent emergence and worldwide spread of the novel coronavirus has resulted in worldwide disease and economic hardship. The virus, known as SARS-CoV-2 is believed to have originated in bats and has spread worldwide through human-to-human virus transmission. It remains unclear which animal species, other than humans, may also be susceptible to viral infection and could naturally transmit the virus to susceptible hosts. In this study, we describe an outbreak of disease and death due to SARS-CoV-2 infection in farmed mink in Utah, United States. The investigation reveals that mink can spread the virus rapidly between animals and that the disease in mink is due to the viral infection and damage to tissues of the upper and lower respiratory system. The determination that mink are susceptible to SARS-CoV-2 indicates the need for strict biosecurity measures on mink farms to remediate mink-to-mink and human-to-mink transmission for the protection of mink, as well as prevent potential transmission from mink to humans.

The breadth of animal hosts that are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and may serve as reservoirs for continued viral transmission are not known entirely. In August 2020, an outbreak of SARS-CoV-2 occurred on five mink farms in Utah and was associated with high mink mortality (35–55% of adult mink) and rapid viral transmission between animals. The premise and clinical disease information, pathology, molecular characterization, and tissue distribution of virus within infected mink during the early phase of the outbreak are provided. Infection spread rapidly between independently housed animals and farms, and caused severe respiratory disease and death. Disease indicators were most notably sudden death, anorexia, and increased respiratory effort. Gross pathology examination revealed severe pulmonary congestion and edema. Microscopically there was pulmonary edema with moderate vasculitis, perivasculitis, and fibrinous interstitial pneumonia. Reverse transcriptase polymerase chain reaction (RT-PCR) of tissues collected at necropsy demonstrated the presence of SARS-CoV-2 viral RNA in multiple organs including nasal turbinates, lung, tracheobronchial lymph node, epithelial surfaces, and others. Localization of viral RNA by in situ hybridization revealed a more localized infection, particularly of the upper respiratory tract. Whole genome sequencing from multiple mink was consistent with published SARS-CoV-2 genomes with few polymorphisms. The Utah mink SARS-CoV-2 strains fell into Clade GH, which is unique among mink and other animal strains sequenced to date. While sharing the N501T mutation which is common in mink, the Utah strains did not share other spike RBD mutations Y453F and F486L found in nearly all mink from the United States. Mink in the outbreak reported herein had high levels of SARS-CoV-2 in the upper respiratory tract associated with symptomatic respiratory disease and death., Author summary The recent emergence and spread of the novel coronavirus has resulted in worldwide disease and economic hardship. The virus, known as SARS-CoV-2 is believed to have originated in bats and has spread worldwide through human-to-human virus transmission. It remains unclear which animal species, other than humans, may also be susceptible to viral infection and could naturally transmit the virus to susceptible hosts. In this study, we describe the early phases of an outbreak of disease and death due to SARS-CoV-2 infection in farmed mink in Utah, United States. The investigation reveals that mink can spread the virus rapidly between animals and that the disease in mink is associated with viral infection and damage to tissues of the upper and lower respiratory system. The determination that mink are susceptible to SARS-CoV-2 indicates the need for strict biosecurity measures on mink farms to remediate mink-to-mink and human-to-mink transmission for the protection of mink, as well as prevent potential transmission from mink to humans. It may be prudent for humans working with SARS-CoV-2 mink to wear appropriate PPE until more is understood.

The Patagonian otter(Lontra provocax)is an endangered species endemic to southern Chile and Argentina. Most of its distribution range has recently been occupied by the American mink(Neovison vison).As part of a long-term study on the impact of mink in Patagonia, we assessed five reversible anaesthetic combination protocols in different doses on wildL. provocaxandN. vison,and described the occurrence of any adverse effects. We assessed 16 anaesthetic procedures with a combination of ketamine-medetomidine (KET-MED; 6.0±2.8-0.05±0.01 mg/kg IM, respectively) or ketamine-dexmedetomidine (KET-DEX; 4.1±0.9-0.02±0.004 mg/kg IM) inL. provocaxand 23 anaesthetic procedures with KET-MED (13.3±4-0.1±0.04 mg/kg IM), KET-DEX (4.8±0.3-0.024±0.001 mg/kg IM) in a low dose of ketamine (LDK) or KET-DEX (10.2±0.9-0.025±0.002 mg/kg IM) in a high dose of ketamine (HDK) inN. vison. Reversal was accomplished using atipamezole at 5 times the dose of MED or 10 times the dose of DEX. All anaesthetic combinations produced complete immobilisation and rapid anaesthetic induction, except for two otters anaesthetised with KET-MED which exhibited a longer time to initial effect. Hypothermia was commonly observed at the end of the anaesthetic procedures. Due to the hypoxemia presented in four otters at the beginning of anaesthesia, it is recommended to use additional oxygen when possible.

Background Recurring escapes or deliberate releases and subsequent infiltration or establishment of feral populations by individuals from fur farms have been commonly noted since the beginning of fur industry expansion. Once animals have invaded ecosystems adjacent to source farms escapees can change the demography of the feral populations through hybridization, outbreeding depression, competition and spreading of various pathogens which can decimate wild populations. In our study, we aimed to assess spread of Aleutian mink disease virus (AMDV) in the feral population of American mink (Neovison vison) in Iceland. The additional objective was to elucidate whether basic morpho-anatomical parameters (i.e., Fulton’s condition factor or spleen to body weight ratio) might be used as a preliminary indicator of AMDV infection. Methods American mink (n = 164) were captured by professional hunters in 8 regions of Iceland. The detection of AMDV in the spleen of male and female individuals was based on PCR amplification of an NS1 gene fragment. Results We confirmed AMDV presence in 23.8% (n = 39) of collected samples with no significant difference in infection rate between males and females. Additionally, we revealed that the prevalence of virus in the feral population was higher closer to fur farms. However, the countrywide prevalence and direction of AMDV distribution needs to be further investigated. Comparison of condition indices in non-infected and infected animals showed significant deterioration of body and spleen parameters in the latter group. Therefore, the application of basic measurements of the American mink may be used to evaluate the health status of individuals in terms of pathogen infection. Conclusions The study shed a new light on prevalence and distribution of AMDV in the feral population of American mink in Iceland and the results might be successfully applied to develop models to infer dynamics of various pathogens, even those latently transmitted by disease-free animals.

This experiment investigated the effect of vitamin A supplementation on growth, serum biochemical parameters, jejunum morphology and the microbial community in male growing-furring mink. Thirty healthy male mink were randomly assigned to three treatment groups, with 10 mink per group. Each mink was housed in an individual cage. The mink in the three groups were fed diets supplemented with vitamin A acetate at dosages of 0 (CON), 20,000 (LVitA) and 1,280,000 IU/kg (HVitA) of basal diet. A 7-day pretest period preceded a formal test period of 45 days. The results show that 20,000 IU/kg vitamin A increased the ADG, serum T-AOC and GSH-Px activities, villus height and villus height/crypt depth ratio (p &lt, 0.05). The mRNA expression levels of IL-22, Occludin and ZO-1 in the jejunum of mink were significantly higher in the LVitA group than those in the CON and HVitA groups (p &lt, 0.05). Vitamin A supplementation increased the diversity of jejunum bacteria, decreased the ratio of Firmicutes to Bacteroidetes and increased the relative abundance of Akkermansia, uncultured bacterium f Muribaculaceae, Allobaculum, Lachnospiraceae NK4A136 group, Rummeliibacillus and Parasutterella. The comparison of potential functions also showed enrichment of glycan biosynthesis and metabolism, transport and catabolism pathways in the vitamin A supplementation groups compared with the CON group. In conclusion, these results indicate that dietary vitamin A supplementation could mediate host growth by improving intestinal development, immunity and the relative abundance of the intestinal microbiota.

Using PCR, we evaluated the presence of parvoviruses and Mycoplasma spp. in 123 American mink (Neovison vison), an introduced invasive carnivore in Chile. Our results showed all analyzed animals were negative for both pathogen groups. We cannot completely dismiss their presence, but if present, their prevalence should be lower than 2%.

International audience; Among the animal superfamily Musteloidea, which includes those commonly known as mustelids, naturally occurring and species-specific alphacoronavirus infections have been observed in both mink (Mustela vison/Neovison vison) and domestic ferrets (Mustela putorius furo). Ferret systemic coronavirus (FRSCV), in particular, has been associated with a rare but fatal systemic disease. In recent months, it has become apparent that both minks and ferrets are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a betacoronavirus and the cause of the coronavirus disease 2019 (COVID-19) pandemic. Several mink farms have experienced SARS-CoV-2 outbreaks, and experimental models have demonstrated susceptibility of ferrets to SARS-CoV-2. The potential for pet ferrets to become infected with SARS-CoV-2, however, remains elusive. During the 2002–2003 SARS epidemic, it was also apparent that ferrets were susceptible to SARS-CoV and could be utilized in vaccine development. From a comparative standpoint, understanding the relationships between different infections and disease pathogenesis in the animal superfamily Musteloidea may help elucidate viral infection and transmission mechanisms, as well as treatment and prevention strategies for coronaviruses.

This paper presents a comprehensive anatomic overview of normal pulmonary vascularization in an American mink (Neovison vison), with emphasis on venous and arterial peculiarities as regards its course and potential disruptions. The study is designed as macro-morphological and vascular network analysis of lungs of fifteen minks of different age and gender. Dissection is conducted along with injection corrosion method in order to clearly visualize the vascular topology, bronchial tree, arterial and venous trees, and their interconnections. The specimens exhibit consistence in the arterial branching pattern with negligible range of alterations. It was noticed that upon leaving the right ventricle of heart, pulmonary trunk divides ventrally from the site of tracheal bifurcation. The divisions were identified as left and right pulmonary arteries, which then ramified in the left and right lung, respectively. Left a. pulmonalis further divides into two major branches ramus lobi cranialis and ramus lobi caudalis, while the right a. pulmonalis gives five major branches for lobes in the right lung. Total of five pulmonary veins leave pulmonary lobes and enter left atrium of the heart. Mink has a distinct niche in biomedical research, proving as a suitable model to enhance the understandings of the various diseases. Gained insights are valuable as reference values for examination of the vasculature in other Mustelidae species, recognition of potential deviations and vascular remodeling due to respiratory diseases.

Streptococcus phocae infection has been described in salmon, sea otters, and several families of pinnipeds. The pathology of the infected animals has mainly been located in the respiratory tract and reproductive system, and with indications of septicemia. In this study, we report the finding of S. phocae in diagnostic material from three unrelated cases of farmed mink. Since S. phocae initially has been described in pinnipeds, two isolates from wild harbor seals were included. All isolates originated from Denmark. To our knowledge, this is the first report of S. phocae infection in mink. The animals (three mink, two seals) were necropsied, and samples were collected for bacteriology, virology, and histopathology. Additionally, the S. phocae isolates were whole genome sequenced and compared to sequences of previously reported isolates from other host species. S. phocae was isolated from the lungs of one mink and one seal with bacteremia, and from one seal with pneumonia. The two remaining mink had dermal infections on the paws and S. phocae was isolated from the lesions. The analysis of the sequence data showed that the three mink isolates and one seal isolate were closely related. Further investigation is needed to conclude whether S. phocae is establishing as commensal in farmed mink and to uncover the infection related pathology in mink. Streptococcus phocae has been described as an emerging pathogen in other species, therefore future awareness and surveillance of this pathogen is crucial.

On many mink farms, antibiotics are used extensively during the lactation period to reduce the prevalence and severity of pre-weaning diarrhoea (PWD) in mink kits (also referred to as greasy kit syndrome). Concerns have been raised, that routine treatment of PWD with antibiotics could affect the natural successional development of the gut microbiota, which may have long lasting consequences. Here we investigated the effects of early life antibiotic treatment administered for 1 week (postnatal days 13–20). Two routes of antibiotic administration were compared to a non-treated control group (CTR, n = 24). Routes of administration included indirect treatment, through the milk from dams receiving antibiotics by intramuscular administration (ABX_D, n = 24) and direct treatment by intramuscular administration to the kits (ABX_K, n = 24). A tendency for slightly increased weight at termination (Day 205) was observed in the ABX_K group. The gut microbiota composition was profiled by 16S rRNA gene sequencing at eight time points between Day 7 and Day 205. A clear successional development of the gut microbiota composition was observed and both treatment regimens caused detectable changes in the gut microbiota until at least eight days after treatment ceased. At termination, a significant positive correlation was identified between microbial diversity and animal weight.

Background The problem of transmission of intestinal microorganisms to tissues occurs when intestinal epithelial cells do not adhere tightly (tight junction), which is caused by improper nutrition, usually associated with poor mucosal status. The impact on maintaining its proper condition in the case of animals also depends on the proper preparation and fragmentation of the ingredients of the feed. Intestinal microbiota disorders are increasingly indicated as one of the causes of many autoimmune, neurodevelopmental and metabolic diseases. However, there are no studies indicating damage to the intestinal barrier of animals resulting in the penetration of microorganisms from the gastrointestinal tract directly into the bloodstream which may result in the development of chronic inflammation. Case presentation On a mink (Neovison vison) farm with a foundation stock of 4,000 females, abscesses were observed in the head, followed by progressive deaths. Antibiotic treatment with amoxicillin and clavulanic acid added to the animals’ feed was not successful. Macroscopic and microscopic changes indicated local suppurative inflammation of the skin and subcutaneous tissue with the presence of purulent fistulas. Microbiological analysis showed a significant increase in Escherichia coli in all samples taken from the abscesses. The results indicate the migration of intestinal bacteria through disturbance of the permeability of the intestinal barrier and their transfer to the blood. Symptoms were alleviated in all animals following changes in the feed components and in feed particle size. Conclusions It is necessary to take into account the possibility of transmission of intestinal bacteria in the etiology of inflammatory diseases in animals. Conducting more research in this field will improve the understanding of the relationship between intestinal microbes and the health of the body as a whole.

Background The disease Fur Animal Necrotizing Pyoderma (FNP) has since 2000 been reported in many fur producing countries including Canada, Finland and Denmark. Development of FNP is characterised by rapidly forming treatment-resistant wounds on paws and in the head region. Economic losses related to FNP have been associated with mortality and decreased fur quality as well as increased veterinary costs. Also it has been suggested that FNP may be associated with reduced production results for breeding mink. The aim of this study was to evaluate if there is an association between FNP lesions in breeding animals and reduced production results based on a retrospective cohort study. Results 1465 breeding animals (244 males and 1221 females) were followed during the breeding season 2019 on five Danish mink farms. Two farms were removed from the analysis since no occurrence of FNP appeared in the observation group. After exclusion, 846 breeding animals (148 males and 698 females) remained in the analysis and were divided into two groups: exposed (EXP) or non-exposed (N-EXP) depending on the disease history of the males during mating. Females exposed to FNP positive males during breeding in average produce 14% fewer kits (P = 0.032) and these females were also more than double as likely to produce small litters (N ≥ 3) than N-EXP females. Female’s from the EXP group were introduced more times to males than females in the N-EXP group (P = 0.0001, 2.5 more times in average). Females in the EXP group did not have a statistically higher risk of becoming barren (P = 0.138) though the relative risk of becoming barren was 77% higher after encountering a FNP male. Conclusions This study shows that FNP has more economic losses for the farms than direct loss of animals. Females in contact with males with FNP lesion during breeding have a higher risk of becoming barren, and produce significantly fewer kits compared to females whom haven’t been in contact with a FNP positive male.

Leptospirosis is a zoonosis of global distribution, caused by the infection of pathogenic Leptospira, a group of bacteria capable of infecting both domestic and wild animals. Mink (Neovison vison) in southern Chile is recognized as a wild and synanthropic rodent predator (among various other prey), and Leptospira infection in them can be acquired through contact with the pathogen in the environment or by eating infected prey. Thus, the aim of this study was to provide more specifics regarding the source of the infection for the American mink under the conditions of Southern Chile. Minks were captured in the Los Rios region, southern Chile, in an area with well-developed dairy farming. Two areas were selected for mink trapping, one with a high degree of dairy farming and a second with a low degree of dairy farming. Within them, 16 study sites were visited, and 45 American mink were trapped and euthanized to obtain kidney tissue and blood serum samples for bacteria isolation and determination of antibodies titers, respectively. Molecular characterization of the isolated strains was performed. Three minks from sites of high-dairy farming industry and only one from sites with low-degree dairy farming were detected as infected through molecular confirmation. This study shows evidence that confirms previous findings made in southern Chile, regarding mink as host of Leptospira interrogans serovar Hardjo-prajitno associated to cattle-farming areas. However, typing information ( Leptospira interrogans Copenhageni and Icterohaemorrhagiae ) suggests that the consumption of rodents may also be a potential source of infection.

SARS-CoV-2, the causative agent of COVID-19, caused respiratory disease outbreaks with increased mortality in 4 mink farms in the Netherlands. The most striking postmortem finding was an acute interstitial pneumonia, which was found in nearly all examined mink that died at the peak of the outbreaks. Acute alveolar damage was a consistent histopathological finding in mink that died with pneumonia. SARS-CoV-2 infections were confirmed by detection of viral RNA in throat swabs and by immunohistochemical detection of viral antigen in nasal conchae, trachea, and lung. Clinically, the outbreaks lasted for about 4 weeks but some animals were still polymerase chain reaction–positive for SARS-CoV-2 in throat swabs after clinical signs had disappeared. This is the first report of the clinical and pathological characteristics of SARS-CoV-2 outbreaks in mink farms.

No abstract Keywords: canine distemper virus; H gene; phylogenetic analysis; amino-acid substitution; N-linked glycolysation; cysteine.

The α-tocopherol (TCP) state as well as enzymatic (superoxide dismutase [SOD] and catalase [CAT]) and nonenzymatic(reduced glutathione [GSH] and retinol) antioxidants in tissues of American minks (Neovison vison) given various levels of dietaryvitamin E were examined. Three groups of farm-bred minks received different amounts of DL-α-tocopheryl acetate (10 mg/kg diet,control; 30 and 110 mg/kg diet, treatments denoted as E30 and E110, respectively) for 14 days in November. The TCP content was raisedsubstantially in the kidneys and reduced in the livers of minks in the E110 group. The action of the 2 vitamin E doses on antioxidantswas similar. The treatments resulted in lower hepatic and kidney retinol levels and hepatic and skeletal muscle SOD, as well as hepaticCAT activities, higher heart SOD activity, and higher kidney GSH content in comparison to the control group. The present results showthat dietary vitamin E intake over 2 weeks considerably changed the TCP status of the liver and kidneys and had tissue-specific actionon measured antioxidants in minks. With the exception of the heart SOD activity, the additional intake of vitamin E reduced antioxidantenzyme activity and augmented the GSH level, indicating an enhancement in the nonenzymatic part of the antioxidant network.

Background Pre-weaning diarrhea (PWD) in mink, also known as “sticky kits”, is a frequently occurring syndrome in suckling mink kits on commercial mink farms. Outbreaks of PWD result in weakened kits, increased mortality and reduced growth and welfare as well as considerable economic losses for the farmers. The syndrome is regarded as multifactorial with a complex etiology, and studies have focused on associations with environment, management and dam characteristics. The present study was conducted from May to June 2015 and included 70 dams with mink litters with and without PWD. The aims were to examine associations between PWD and mastitis (bacterial infection and histological signs of inflammation or other lesions in the mammary gland), and to examine associations between PWD and other dam-related characteristics (age, litter size, body mass index, and weight and number of active mammary glands of the dam). Results Using multivariable mixed logistic regression analyses with farm id as a random intercept, we found that the odds for PWD in the litter were significantly higher in 1 year old dams versus > 1 year old (OR = 13.3, CI 2.0–90.2, P = 0.01), higher if litter size observed after birth was > 5 kits versus ≤ 5 kits (OR = 16.5, CI 2.2–123.7, P = 0.01), higher if the number of active mammary glands per kit was ≤ 1.5 versus > 1.5 glands per kit (OR = 6.5, CI 1.2–36.0), P = 0.03), and higher in farms with high prevalence of PWD versus low prevalence (OR = 16.8, CI 2.9–97.6, P = 0.002). There were no significant associations between PWD and bacterial infection, histological signs of inflammation or other lesions of the mammary gland, body mass index or weight of mammary gland per kit. Conclusion Pre-weaning diarrhea had a statistically significant association with age of the dam, litter size and the number of active mammary glands per kit. However, PWD was not associated with mastitis, body mass index and weight of mammary gland tissue per kit.

Introduction: The aim of the study was to investigate the mechanical and geometric properties as well as bone tissue and mineral density of long bones in mink dams exposed to deoxynivalenol (DON) since one day after mating, throughout gestation (ca. 46 d) and lactation to pelt harvesting. Material and Methods: Thirty clinically healthy multiparous minks (Neovison vison) of the standard dark brown type were used. After the mating, the minks were randomly assigned into two equal groups: nontreated control group and DON group fed wheat contaminated naturally with DON at a concentration of 1.1 mg·kg-1of feed. Results: The final body weight and weight and length of the femur did not differ between the groups. However, DON contamination decreased mechanical endurance of the femur. Furthermore, DON reduced the mean relative wall thickness and vertical wall thickness of the femur, while vertical cortical index, midshaft volume, and cross-sectional moment of inertia increased. Finally, DON contamination did not alter bone tissue density, bone mineral density, or bone mineral content, but decreased the values of all investigated structural and material properties. Conclusion: DON at applied concentration probably intensified the process of endosteal resorption, which was the main reason for bone wall thinning and the weakening of the whole bone.

Feed quality is generally assumed to affect health status in animal production. In previous studies, the feed producer has been found to affect the occurrence of gastrointestinal disease and antimicrobial use in Mink (Neovison vison). Mink are fed with moist, freshly produced feed, based on perishable ingredients. The objective of this study was to investigate the potential effect of specific feed parameters on antimicrobial use on herd level. The study was cross-sectional, including 1472 mink herds, responsible for 97% of oral antimicrobials prescribed for Danish mink during the study period, 2012–2014. Data were obtained from the national veterinary prescription database (VetStat), Kopenhagen Fur database, and the Voluntary Feed Control (Mink producers Organization). All feed batches subject to feed control were included. A multi-variable variance analysis was carried out analysing the effect of the feed parameters total volatile nitrogen, dry matter, crude protein and fat; total bacterial count (21 °C), and counts of sulphite producing bacteria (21 °C), Clostridium spp., faecal cocci (FC) (44 °C), yeast, and mould; presence of Salmonella spp. and Clostridium perfringens (dichotome). Three outcome variables were applied: prescription of oral antimicrobial on herd level within time slots of 3, 5 or 7 days after feeding of an included batch. Two binomial models were developed, adjusting for significant effects (p

This article contains the results of morphological studies of liver in the American mink (Neovison vison) by atomic force microscopy. We have performed the visualization of hepatocytes, principal cell structures, and intercellular contacts. In contrast to studies on the liver structure by electron microscopy, it is found that hepatocytes have an uneven structure and polygonal shape with a thick central part (with nucleus) and oblong polar parts. The nucleus of the hepatocytes has a round or oval shape, uneven surface, and notable karyolemma. The nucleolus is located on the surface of the nucleus and has a pyramidal shape. The texture of the cytoplasm is unevenly nodular, and the edges of intercellular contacts are uneven. Our data on the nanostructure of liver can be used in measuring of morphological parameters of healthy organs in minks and for the comparative diagnostics of hepatic pathologies.

BackgroundIndividual differences of mink, including color type, are speculated to affect the course of wound healing, thereby impacting wound assessment and management on the farms, as well as the assessment of wounds in forensic cases. In this study, we examined the effect of color type on early wound healing in farmed mink. Full thickness excisional wounds (2 × 2 cm) were made on the back in 18 mink of the color types Brown, Silverblue and Blue Iris. Gross and microscopic pathology of the wounds was evaluated 2 days post-wounding together with degree of wound size reduction, presence of bacteria and blood analyses.ResultsPathological examination on day 2 showed the greatest mean wound size reduction in Brown mink (11.0%) followed by Blue Iris (7.9%) and Silverblue (1.6%). Bacteria were cultured from all wounds, and predominantly Staphylococcus species were recovered in mixed or pure culture. Histopathology from day 2 wounds showed a scab overlying necrotic wound edges, which were separated from underlying vital tissue by a demarcation zone rich in polymorphonuclear leukocytes. Fibroblasts and plump endothelial cells were more numerous in the deeper tissues. Complete blood count parameters were within normal ranges in most cases, however, the mink showed mildly to markedly decreased hematocrit and six mink of the color types Silverblue and Blue Iris showed moderately elevated numbers of circulating segmented neutrophils on day 2. There was a marked increase in concentration of serum amyloid A from day 0 to day 2 in all color types.ConclusionsWe have described differences in early wound healing between mink of the color types Brown, Silverblue and Blue Iris by use of an experimental wound model in farmed mink. The most pronounced difference pertained to the degree of wound size reduction which was greatest in Brown mink, followed by Blue Iris and Silverblue, respectively.

It has been known that selective breeding of animals for behavior associated with domestication changes a variety of physiological traits including response to stress and hypothalamo–pituitary–adrenocortical system activity. The aim of our research was to find association between behavioral type and differential leukocyte counts as an indicator of homeostasis activity. We used farm-raised 5-month-old minks ( Neovison vison ) that had been selective bred for 17 generations on the basis of behavior toward human. After selection, minks were divided into the following groups: aggressive (from −4 to −1), "domestic" (from +1 to +5). Blood leukocytes were analyzed in 5-month-old minks (n = 105) of different behavior lines: aggressive (−1, −2), "domestic" (+1 and from +3 to +5), fearful, and minks never subjected to selective breeding (control). We found strong effects of selection for behavior of minks on differential blood leukocyte count. There were differences between behavior types in differential leukocyte counts. Neutrophils and eosinophils were the leukocyte types the most sensitive to selection for behavior. The counts of eosinophils in peripheral blood in "domestic" (+3, +5) minks were higher than in control and aggressive (−2) minks. The percentage of neutrophils was higher in the most aggressive minks (−2) in comparison to "domestic" minks. We have concluded that differences found in leukocytes profile are the result of neuroendocrine system modification.

This study was conducted to investigate the effects of dietary vitamin E (VE) supplementation on the reproductive performance of female mink, preweaning growth performance of their kits, and antioxidative status and immune functions of dams and kits. Yearling mink dams (n = 180) were randomly assigned to five treatment groups (n = 36). The dietary treatments included a basal diet supplemented with VE at 0 (control), 80, 160, 320, or 640 mg/kg DM. Compared with the control, the addition of 160–320 mg/kg VE decreased (P = 0.0362) the percentage of pre-weaning mortality of mink kits. At weaning, the average body weight was greater (P = 0.0408) in kits fed 320 mg/kg supplemental VE. In mink dams, the addition of 80–320 mg/kg VE increased (P = 0.0125) serum SOD. Supplementation of 320 or 640 mg/kg VE decreased (P = 0.0260) serum reactive oxygen species (ROS). Furthermore, feeding a large dose of VE (640 mg/kg diet) resulted in increased (P = 0.0245) serum α-tocopherol. In mink kits, the addition of 320 or 640 mg/kg VE increased serum α-tocopherol (P = 0.0207) and IgG (P = 0.0464). Supplementation of 640 mg/kg VE decreased (P = 0.0471) serum ROS. The present results indicate that VE supplementation improved the antioxidative status of mink dams and enhanced the immune functions, decreased pre-weaning mortality and enhanced weaning weight of their kits. Taken together, the effective VE supplementation was 320 mg/kg of diet for yearling female mink.

Avian influenza A viruses (AIVs) can occasionally transmit to mammals and lead to the development of human pandemic. A species of mammal is considered as a mixing vessel in the process of host adaptation. So far, pigs are considered as a plausible intermediate host for the generation of human pandemic strains, and are labelled ‘mixing vessels’. In this study, through the analysis of two professional databases, the Influenza Virus Resource of NCBI and the Global Initiative on Sharing Avian Influenza Data (GISAID), we found that the species of mink (Neovison vison) can be infected by more subtypes of influenza A viruses with considerably higher α-diversity related indices. It suggested that the semiaquatic mammals (riverside mammals), rather than pigs, might be the intermediate host to spread AIVs and serve as a potential mixing vessel for the interspecies transmission among birds, mammals and human. In epidemic areas, minks, possibly some other semiaquatic mammals as well, could be an important sentinel species for influenza surveillance and early warning.

Three fishers ( Martes pennanti), 2 gray foxes ( Urocyon cinereoargenteus), 1 mink ( Neovison vison), 1 skunk ( Mephitis mephitis), and 1 raccoon ( Procyon lotor), from Vermont and New Hampshire, had lesions on autopsy consistent with canine distemper virus (CDV) infections diagnosed in a 12-mo period in 2016–2017. Lesions of CDV infection were most commonly noted in the lungs (8 of 8 animals), urothelium (5 of 8), biliary tract (5 of 8), gastrointestinal tract (4 of 7), and brain (4 of 6). Splenic lesions were seen in 3 animals. The diagnosis was confirmed via immunohistochemistry and virus isolation. Viral genotyping indicated that all 8 animals were infected with a distinct clade of CDV that has only been reported in wildlife in New England, and this clade of viruses is distinct from vaccine strains. During the 12 mo when these cases occurred, no other CDV clade was identified in any other wildlife or domesticated animal submitted from the 2 states.

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is widely distributed in the Danish pig production. Spillover to the mink production is hypothesized to occur via contaminated pig by-products used in the production of mink feed. The aim of the present longitudinal experimental cohort study was to confirm the potential of LA-MRSA being transmitted to naïve mink after exposure to contaminated feed, and to study the persistence of the bacterium on the animals after ceased exposure to contaminated feed. LA-MRSA-negative mink (n = 28) were housed in pairs in 14 mesh cages. Twenty-four mink (12 cages) received around 5.1 × 10 8 cfu/mink in the feed for five days, while four mink (two cages) were kept as negative controls and fed with LA-MRSA negative feed. Twenty-four hours after initiation of spike, all 28 min. were tested LA-MRSA-positive by paw swabs. After cease of the spiking period, one mink per cage were moved to a clean housing facility to study the potential effect of environmental contamination in persistence of the LA-MRSA. All mink were re-tested three times per week for the subsequent 26 days to study whether the mink cleared off the bacterium. The results showed that LA-MRSA can be transmitted to paws and pharynx on mink after exposure to contaminated feed and that LA-MRSA may spread indirectly through contaminated environmental sites. Mink tend to clear off LA-MRSA, however, the bacterium may persist on mink for more than 26 days.

Background Pre-weaning diarrhea (PWD) is a severe syndrome, with world-wide occurrence, affecting farmed mink (Neovison vison) kits during the lactation period. Kits affected by PWD often display clinical signs such as: yellow-white diarrhea, greasy skin, and dehydration. In severe cases the kits eventually die. It is common practice to treat PWD using antimicrobials; however the effect is not well documented. Due to the multifactorial etiology of PWD vaccine development is not feasible. The role played by the immune status of the mink kits with respect to their susceptibility to PWD is not well studied. To elucidate the possible association between PWD and total IgG serum concentration in young kits we analyzed blood collected from kits from 100 litters on two mink farms during the same breeding period, one farm being a case farm with high prevalence of PWD, and the other being a control farm with no cases of PWD. Results Kits affected by PWD had a significantly reduced weight gain compared to unaffected control kits. Litters born later in the breeding period came down with PWD at an earlier age than litters born at the start of the breeding period. We found that PWD affected kits had significantly lower concentrations of serum IgG compared to unaffected kits at 13–15 days of age (the last blood sampling point of the study). Conclusion The results in this study suggest that PWD affected kits less efficiently absorbed IgG from maternal milk or had a lower intake of maternal milk, potentially contributing to the exacerbation of disease. A lower intake of IgG and/or less absorption from maternal milk could also pre-dispose kits for PWD. Future studies will be needed to elucidate if the circulating level of IgG is directly related to protection against disease and to investigate if administration of IgG could be helpful in alleviating and/or preventing PWD in mink kits.

The reproduction of the mink, Neovison vison, has been extensively studied over the past 70 years. The endocrine control of pregnancy is reasonably well understood, but our understanding of early embryo development is limited. The mink is one of the best characterized mammals for the study of embryonic diapause, but in order to unravel the complex interactions that occur between the blastocyst and the uterus during diapause and reactivation, a defined culture media system that supports growth is essential. Until recently, culture of the mink blastocyst has been relatively unsuccessful. This chapter will describe a method for successfully obtaining and culturing mink blastocysts and will highlight some of the unique challenges in working with this species. Methods to age match prediapause embryos in a mammal that exhibits superfetation, and to synchronize collection of reactivation from diapause stages using prolactin will be discussed. Finally, a quantitative method to determine the extent of cell proliferation in the blastocyst, a hallmark of reactivation from diapause, will be detailed.

The aim of the present study was to identify the animal prevalence and environmental reservoir of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in mink farms. LA-MRSA on mink constitutes a human health hazard to farmers and farm workers, who handle the animals and are at risk of bites and scratches from colonized sites. The primary route of LA-MRSA colonization of mink is suspected to be by ingestion of contaminated pig by-products.We performed a cross-sectional study with repeated measurements during May-July 2017. A total of 644 mink carcasses (542 mink kits and 102 breeding animals) from five Danish farms were sampled. From each carcass, pharynx was swabbed and the right forepaw dissected. In addition, environmental samples covering feed, air, glove, cages (top and between) and nest boxes were collected on the farms. MRSA was selectively cultured from each sample and suspect colonies were assessed using matrix-assisted laser desorption ionisation (MALDI-TOF) for species confirmation. Further, from each farm, three isolates from mink and one isolate per positive environmental site were sent for whole genome sequencing.We isolated LA-MRSA from mink in four out of the five farms, but LA-MRSA bacterium was detected on all farms. On farms with LA-MRSA positive animals, the overall apparent animal prevalence ranged from 20% [13;29] CI95% to 29% [22;38]CI95%. LA-MRSA was isolated from kits before weaning, most likely due to a contaminated environment or transfer from the dam. Further, the apparent prevalence of LA-MRSA in kits tended to increase during the first months of age. On farms where LA-MRSA was isolated from mink, LA-MRSA was also isolated from the environment. LA-MRSA was isolated from all environmental sites tested (i.e. glove, on top of and between the cages and in the nest boxes), apart from air. The negative air samples contrast with the high concentrations of LA-MRSA in air found in the pig production. Hence, the risk of human exposure to LA-MRSA on mink-farms tends to be associated mainly with direct contact with contaminated environmental sites and the handling of colonized mink. All sequenced isolates were confirmed as LA-MRSA CC398 and genetically similar to clones previously isolated from the Danish pig production, supporting the hypothesis of LA-MRSA being transmitted by contaminated pig by-products.

This experiment was conducted to investigate the effects of supplemental vitamin A (VitA) on the growth performance, nutrient digestibility, serum biochemical parameters, and liver histology of growing-furring mink kits (Neovison vison). Ninety healthy male mink were randomly assigned to 6 treatment groups, with 15 mink per group. Each mink was housed in an individual cage. Mink in the 6 groups were fed diets supplemented with vitamin A acetate at dosages of 0 kIU/kg (VitA 0), 5 kIU/kg (VitA5), 20 kIU/kg (VitA20), 80 kIU/kg (VitA80), 320 kIU/kg (VitA320) or 1280 kIU/kg (VitA1280) of the basal diet. A 7-day pretest period preceded a formal test period of 60 days. The results showed that the final body weight (BW), average daily gain (ADG), weight gain (WG), average daily feed intake (ADFI) and the digestibility of dry matter (DM), crude protein (CP), ether extract (EE), and carbohydrate (CHO) exhibited a quadratic relationship (P

Toll-like receptors (TLRs) can recognize conserved molecular patterns and initiate a wide range of innate and adaptive immune responses against invading infectious agents. The aim of this study was to assess the transcript profile of mink TLRs (mTLRs) in mink peripheral blood mononuclear cells (PBMCs) and a range of tissues, and to explore the potential role of mTLRs in the antiviral immune response process. The results indicated that the mTLR partial nucleotide sequences had a high degree of nucleotide identity with ferret sequences (95-98%). Phylogenetic analysis showed that mammalian TLRs grouped into five TLR families, with a closer relationship of the mTLRs with those of ferret than the other mammalian sequences. Moreover, all the mTLRs were ubiquitously expressed in lymphoid organs (spleen and lymph nodes) and PBMCs. Interestingly, the mTLR expression patterns in lung, uterus, and heart showed quite a lot of similarity. Another remarkable observation was the wide expression of mTLR1-3 mRNAs in all tissues. Among the analyzed tissues, skeletal muscle was revealed to being the lowest repertoire of mTLR expression. Additionally, mink PBMCs exposed to the canine distemper virus revealed significant upregulation of mTLR2, mTLR4, mTLR7, and mTLR8 mRNAs, indicating that mTLRs have a role in innate immunity in the mink. Collectively, our results are the first to establish the basic expression patterns of mTLRs and the relationship between mTLRs and a virus, which will contribute to better understanding of the evolution and the functions of mTLRs in the innate immune system in minks.

American minks ( Neovison vison ), which cause great impacts on local small and median sized animals through direct predation and diseases tramission, had been characterized as an invasive species worldwide. As well-known fur animals, American minks were introduced to Europe in early 20th century, and to China in mid-20th century. American minks spread nearly entire Europe soon after escaping from fur farms in European countries, and they had already established naturalized population in northern Altai Mountain in Russia for years. Northern Altai Mountain is one of the main distribution areas of American minks in Russia. In recent years, American minks were reported in southern Altai mountains (Altai region, or Chinese Altai) in Xinjiang, China. American minks occurred in forest parks and national nature reserves in Altai region. Earlier records in China were misidentified as European minks or both of them. Based on field survey and photo identification, we confirmed that all these records were belong to American minks. Although American minks had been imported to China for over half a century, now they were found in wild in north-western China instead of eastern China, where had more mink farms. Thus American minks found in Chinese Altai may be border-crossing invaders. Through field survey and investigation, American minks were not rare in the forest parks and nature reserves of Chinese Altai region, thus we suggested that American mink had already established populations in China. We discussed the potential impacts of American minks invasion in China through habitat simulation, potential prey and competing species, and wildlife diseases. We discussed the current status of otters in China, which had similar niches to minks. Using MaxEnt model for habitats simulation at global scales, we predicted climate-suitable areas for American minks. We find that coastal regions of North America, south tip of South America, Europe, Eastern Asia, North Africa, South Eastern Australia and New Zealand harbor highly suitable habitats of American minks. All these coastal areas should be exceptionally precautious for live minks transport. In addition, mountains of Central Asia are the only inland highly suitable habitats of American minks. Central Asia harbors plentiful endemic fishes, and should be precautious for American minks invasion. In China, Chinese Altai and middle to lower reaches of Yangtze River are highly suitable habitats for American minks, where otters are almost disappeared. As China’s first alien carnivore, American minks will impose great predation pressures on endemic waterfowls and fishes, and will have impact on China’s endangered otters and other mustelids. All three major minks epidemic diseases: canine distemper, Aleutian disease and mink viral enteritis had already have outbreak records in Chinese mink farms, and theses diseases had been proven to transmit to wildlife. In addition, China the has largest mink farming industry of the world. Therefore, besides controlling border-crossing invasion, eco-security assessments should be strengthened in domestic mink farms.

Skrjabingylus nasicola (Leuckart, 1842) are geographically widespread nematodes that parasitize the nasal and frontal sinus cavities of smaller mustelids. As most prior work was solely based on the analysis of bone injuries of museum skull, little is known about the determinants and effects of infestation in the host species. Working on fresh skulls, we aimed to analyze infestation patterns in American mink (Neovison vison Schreber, 1777) from nine study areas in northern Germany and to identify factors that explained infestation prevalence and intensity in the host species. The prevalence (46.7-62.9 %) and infestation intensity values (4.5-10.89 nematodes) reported here were relatively large, especially compared to other American mink populations in Europe. Considering mink diet, our study sites probably harbored a larger number of infested paratenic hosts and climate did not have a substantial negative influence on survival of S. nasicola larvae. We did not observe any significant sex-age differences in either prevalence or intensity of S. nasicola infestation. We did not find a negative impact of an infestation on the host animals' body weight, confirming prior results that the parasite is not a significant mortality factor in mustelids. Our study suggests that this holds even outside the native distributional range where the host's defenses might not be optimally adapted to an autochthonous parasite.