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Zoonotic transmission of SARS-CoV-2 from infected humans to other animals has been documented around the world, most notably in mink farming operations in Europe and the United States. Outbreaks of SARS-CoV-2 on Utah mink farms began in late July 2020 and resulted in high mink mortality. An investigation of these outbreaks revealed active and past SARS-CoV-2 infections in free-roaming and in feral cats living on or near several mink farms. Cats were captured using live traps, were sampled, fitted with GPS collars, and released on the farms. GPS tracking of these cats show they made frequent visits to mink sheds, moved freely around the affected farms, and visited surrounding residential properties and neighborhoods on multiple occasions, making them potential low risk vectors of additional SARS-CoV-2 spread in local communities. [ABSTRACT FROM AUTHOR]

Nova Scotia produces more mink pelts than any other province, but its fur farming industry imposes costs disproportionate to its benefits. These costs include the substantial financial aid given to mink farms, the toxic algae blooms in some lakes, the frequent spread of viruses from mink to humans and wildlife, the regular and wasteful mass culls of diseased mink, and the animal suffering caused by captivity, neglect, and abuse. Federal and provincial legislation does not and cannot provide meaningful protection to mink because of innate species characteristics and the cruelties inherent in the fur industry. Due to the association between mink farming and the spread of COVID-19, British Columbia plans to prohibit the practice; Nova Scotia should do the same. [ABSTRACT FROM AUTHOR]

Aleutian mink disease virus (AMDV) is one the most relevant pathogens of domestic mink, where it can cause significant economic losses, and wild species, which are considered a threat to mink farms. Despite their relevance, many aspects of the origin, evolution, and geographic and host spreading patterns of AMDV have never been investigated on a global scale using a comprehensive biostatistical approach. The present study, benefitting from a large dataset of sequences collected worldwide and several phylodynamic-based approaches, demonstrates the ancient origin of AMDV and its broad, unconstrained circulation from the initial intercontinental spread to the massive among-country circulation, especially within Europe, combined with local persistence and evolution. Clear expansion of the viral population size occurred over time until more effective control measures started to be applied. The role of frequent changes in epidemiological niches, including different hosts, in driving the high nucleotide and amino acid evolutionary rates was also explored by comparing the strengths of selective pressures acting on different populations. The obtained results suggest that the viral passage among locations and between wild and domesticated animals poses a double threat to farm profitability and animal welfare and health, which is particularly relevant for endangered species. Therefore, further efforts must be made to limit viral circulation and to refine our knowledge of factors enhancing AMDV spread, particularly at the wild-domestic interface. [ABSTRACT FROM AUTHOR]

Danish and European legislation recommend mink breeding programs that include selection for "confidence," defined as exploratory activity in a standardized behavioral test. Although this recommendation may improve mink welfare, farmers may consider this criterion risky due to possible negative consequences on other traits. The overall objectives of this study were to estimate the heritability of exploratory/fearful behavior and to identify genetic correlations with other traits of major economic importance in mink fur production. Various aspects of social influence on exploratory/fearful behavior, such as effects of the mother and litter siblings before weaning, the mother's age, and cage mates after weaning, were analyzed. In total, 26,371 1-yr-old Brown mink (Neovison vison) individuals born during the period of 2013 to2016 were included in the study. Exploratory/fearful behavior was the main trait analyzed. The production traits analyzed were live pelt quality and body weight. Both of these traits were assessed during live grading in November. Pelt length and quality were determined using the dried pelts of nonbreeders. Fertility data were obtained from the Fur Farm database. Linear mixed models were run using the restricted maximum-likelihood method. The genetic correlation between female and male behavior was 0.95 (SE = 0.06), indicating similar genetic backgrounds for both sexes (P = 0.40). For both sexes, the estimated heritability of behavior was 0.19 (SE = 0.03). We found no significant genetic correlation between behavior and production/fertility traits (P > 0.05). Common litter variance indicated a preweaning effect of litter mates and/or dam on postweaning temperament. There was a tendency for offspring from older mothers to explore more than offspring from 1-yr-old mothers. This trend was especially pronounced for males of 2-yr-old mothers (P = 0.05) and females of 4-yr-old mothers (P = 0.06). We conclude that confidence may be selected for among farm mink without detrimental effects on economically important production traits, such as pelt quality and fertility. [ABSTRACT FROM AUTHOR]

Highlights • LA-MRSA is found in 20–29% of the mink on positive farms. • LA-MRSA was isolated from kits before weaning, possibly due to a contaminated environment or spill-over from the dam. The prevalence in mink kits tends to increase during the first months of age. • Apart from air, LA-MRSA is widely distributed in the environment on positive mink farms. • Human exposure through air is unlikely. However, mink farmers should be aware of the risk of contamination through direct contact with environmental sites and the handling of colonized mink. Abstract 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. [ABSTRACT FROM AUTHOR]

The American mink (Neovison vison), native to North America, is a controversial invasive species in many European countries, including Poland. Mitochondrial DNA data (concatenated MT-CYTB and MT-COI sequences) were used to investigate the genetic diversity of native, introduced, and farm populations of this species. Phylogenetic analysis revealed two major clades including individuals from the farm, feral, and wild populations. This supports the origin of Polish minks from the two native lineages existing in North America. The genetic structure in the invasive range may result from the diverse origins of the released founder individuals and the rapid expansion and contact zones of the introduced populations. Spatial mixing of both North American lineages in Polish feral populations may lead to higher levels of genetic diversity in introduced populations, despite some evidence of a founder effect as one of the main factors influencing their diversity. [ABSTRACT FROM AUTHOR]

Genetic characteristics play an important role in alien species for achieving high adaptation and rapid evolution in a new environment. The American mink (Neovison vison) is one of the best-known and most widespread invasive species that has successfully invaded the Eurasian mainland over quite a short period, including most parts of northeastern China. However, genetic information on farmed and feral American mink populations introduced in China is completely lacking. In this study, we combined mitochondrial DNA sequences and polymorphic microsatellites to examine the genetic divergence and genetic diversity of farmed and feral American mink populations. Our results suggest that there is admixture of individuals of different genetic characteristics between farmed and feral populations of mink. Furthermore, the genetic diversity of both farmed and feral American mink populations was high, and no bottleneck or population expansion was detected in most of the populations. These findings not only highlight the genetic characteristics of American mink in northeastern China but also contribute to the general understanding of the invasiveness of farmed species.

The article presents highlights on SARS-CoV-2 and other different strains of coronavirus (CoV) transmission routes from animals to humans. Topics include evidence of SARS-CoV-2 spillover back and forth between animals and humans within mink farms; Human SARS-CoV-2 strains infect susceptible domestic animals and likely adapt to these species through mutation; and SARS-CoV-2 can also be transmitted to humans through contact with contaminated uncooked meat or food packaging.

The American mink, an invasive mammal introduced to Europe, severely impacts native biodiversity. The history of its invasion has been poorly investigated in central and eastern Europe, and the current variations in densities of mink populations are not well studied, thus making a reduction of its impact difficult. Here we analyse the temporal dynamics and spatial distribution of the American mink population in Poland, which began to establish itself at the beginning of the 1980s and originated from Polish farm escapees and immigrants from Lithuania and Belarus. Mink dispersal started in the north and continued to the south and in 2016 mink occurrence was recorded across ca. 75% of the country. By about 1997 mink had colonised half of Poland, and in 2016 the only mink-free area was in the south and south-east of the country. The rate of expansion showed accelerating and decelerating patterns, and reached its maximum 12 years after the beginning of the expansion. Mink farming in western Poland developed rapidly after 2000 and probably influenced acceleration of mink range expansion rates in years 2006-2008. Indices of mink densities showed significant nonlinear change over time since local populations were established and were highest in populations estimated to be 10-15 years old. The prediction of non-native species invasion rates and population dynamics should be incorporated into management actions curbing their negative impact on native fauna. [ABSTRACT FROM AUTHOR]

A survey was conducted on 30 Danish mink farms from April to October 2016 to determine the prevalence and species of Eimeria in Danish farmed mink. In total, 2.6% of mink faecal samples (108/4140) were positive for Eimeria vison-like oocysts by microscopy, with 24.8% (78/315) of mink being positive at least once during the study period. Morphological analysis of sporulated oocysts (n = 20) identified Eimeria vison-like oocysts measuring 21.0 × 13.8 μm with a length/width (L/W) ratio of 1.5. Phylogenetic analysis of 18S rRNA sequences (1221 bp) from three positive mink indicated that Eimeria vison-like shared the highest genetic similarity to Eimeria sp. ex Apodemus agrarius from a Striped field mouse (A. agrarius) from the Czech Republic (99.6%). Analysis of a shorter region of 18S (531 bp) revealed that the E. vison-like genotype sequences grouped in the same clade and shared 97.7% similarity with E. furonis. At the cytochrome c oxidase subunit I (COI) locus, mink-derived sequences were not available from GenBank and phylogenetic analysis placed the novel E. vison-like in a clade with E. cf. ictidea (99.4% similarity) from a black footed ferret (Mustela nigripes) from Canada. [ABSTRACT FROM AUTHOR]

Flies are known vectors for a variety of infectious diseases in animals. In fur mink farming, one of the most severe diseases is Aleutian disease, which is caused by the Aleutian mink disease virus (AMDV). The presence of large fly populations is a frequent issue in mink farms; however, no studies assessing their role as AMDV carrier vectors have been conducted to-date. In order to determine the presence of AMDV in aerial flies from an infected mink farm, flies ( n  = 254) and environmental swab samples ( n  = 4) were collected from two farm barns. Fannia canicularis (L.) (Diptera: Muscidae) represented more than 99% of the fly population. One hundred and fifty specimens of this species were divided into pools of ten flies and analysed by qPCR, and positive samples were further sequenced. All fly pools and environmental samples tested positive for AMDV, and sequence analysis revealed identical genotypes in both types of samples. This is the first report of AMDV contamination in flies from mink farms, suggesting that F. canicularis may act as an AMDV vector. These results may be of interest for epidemiological studies and also for the improvement of control measures against this virus in mink farms. [ABSTRACT FROM AUTHOR]

Two groups of minks of 10 animals each were selected for the study. The 1st group being the control and the 2nd group was treated to a diet contaminated with T-2 toxin at a dose of 100 µg / kg of feed in combination with aflatoxin B1 at a dose of 50 µg / kg of feed with the maximum permissible dose levels currently accepted in Russia for 30 days. Hematological and biochemical blood tests were performed every 10 days. The T-2 toxin and aflatoxin B1 has statistically significant changes in the hematological parameters, the erythrocyte count decreased by 32.1%, the leukocyte count went down by 39, 3% and the erythrocyte sedimentation rate increased by 16.7%. Serum protein content decreased by 27.4%, the ratio of blood protein fractions changed and the activity of some blood enzymes increased. The other notable observations were reduced appetite, diarrhoea changes in the pelts, alopecia and dull and disheveled coats. The study revealed the need for revising the existing safety standards for mink feeds with regard to the limit values for mycotoxins. [ABSTRACT FROM AUTHOR]

The article informs that according to a study published in the journal "Eurosurveillance," a deadly avian influenza virus, H5N1, has been discovered in a mink farm in northwestern Spain. It mentions that the episode has raised concerns about H5N1 triggering a human pandemic as it has spread through a densely packed mammalian population and gained a mutation that favors mammal-to-mammal spread.

Background: Aleutian mink disease has major economic consequences on the mink farming industry worldwide, as it causes a disease that affects both the fur quality and the health and welfare of the mink. The virus causing this disease is a single-stranded DNA virus of the genus Amdoparvovirus belonging to the family of Parvoviridae. In Denmark, infection with AMDV has largely been restricted to a region in the northern part of the country since 2001, affecting only 5% of the total Danish mink farms. However, in 2015 outbreaks of AMDV were diagnosed in all parts of the country. Initial analyses revealed that the out breaks were caused by two different strains of AMDV that were significant different from the circulating Danish strains. To track the source of these outbreaks, a major investigation of global AMDV strains was initiated. Methods: Samples from 13 different countries were collected and partial NS1 gene was sequenced and subjected to phylogenetic analyses. Results: The analyses revealed that AMDV exhibited substantial genetic diversity. No clear country wise clustering was evident, but exchange of viruses between countries was revealed. One of the Danish outbreaks was caused by a strain of AMDV that closely resembled a strain originating from Sweden. In contrast, we did not identify any potential source for the other and more widespread outbreak strain. Conclusion: To the authors knowledge this is the first major global phylogenetic study of contemporary AMDV partial NS1 sequences. The study proved that partial NS1 sequencing can be used to distinguish virus strains belonging to major clusters. The partial NS1 sequencing can therefore be a helpful tool in combination with epidemiological data, in relation to outbreak tracking. However detailed information on farm to farm transmission requires full genome sequencing. [ABSTRACT FROM AUTHOR]

Background: Mink are an important animal commodity group in Canada and excessive kit mortality represents a significant loss to production. National biosecurity standards have been developed for Canadian mink farms, but it is unclear how well these standards have been implemented as there are no studies correlating management practices of mink producers with causes of death in mink kits. To that end, we surveyed Ontario mink producers on their biosecurity and management practices and conducted almost 5660 post mortem examinations on found-dead, preweaned kits to characterize mink farm biosecurity practices and causes of death in preweaned kits. Results: We found that very few biosecurity and management practices were uniformly used by producers, despite good awareness of appropriate practices. Use of personal protective equipment was implemented by fewer than 50% of respondents, while control of mink shed access, disinfection of feed containers after use, and use of a rodent control program were the only practices implemented by greater than 70% of respondents. Only 18% of producers reported regular use of antimicrobials in feed or water, although 91% stated they used antimicrobials for treatment of bacterial diseases on a regular basis. On post mortem examination, no gross abnormalities were noted in 71% of the kits, 45% were thought to be stillborn or aborted, 27% had some form of abnormal fluid distribution in the body, and 2% had a congenital malformation. A subset of 69 gastrointestinal tract samples was submitted for bacterial culture, of which 45 samples yielded sufficient growth. Most interesting was the identification of Salmonella enterica serovar Heidelberg in 11% of samples. Conclusions: The results of this study will provide a benchmark for Canadian mink producers and their veterinarians, defining the areas to which greater attention should be given to ensure more rigorous biosecurity practices are in place. Ultimately, these improvements in practices may contribute to increased mink production and animal well-being. [ABSTRACT FROM AUTHOR]

Background: Pre-weaning diarrhea in mink, also known as "sticky kits", is a syndrome and outbreaks occur every year on commercial mink farms in all mink producing countries. Morbidity and mortality can be considerable on a farm with huge economic consequences for the farmer as well as compromised welfare for the mink kits. Although efforts have been taken to identify etiologic agents involved in outbreaks, the syndrome is still regarded as multifactorial and recurring problems on the same farms draw attention to management and environmental risk factors. In the preweaning period from May to June 2015, a case control study was carried out on 30 Danish mink farms. Data concerning management, biosecurity, hygiene, feed consumption, antibacterial prescription and production efficiency were analyzed. Results: The proportion of 1-year old females, farm size (total number of females), energy supply per female in the late gestation period, and dogs accessing the farm area were significantly associated with being a case farm. Case farms were prescribed almost twice the amount of antibacterials per gestational unit (female and litter) as in control farms. Farmers on case farms spent significantly more time nursing and treating the animals and experienced more females with mastitis compared to farmers on control farms. No significant differences in cleaning practices or hygienic measures between case and control farms were found and there were no differences in drinking water quality, bedding material, composition neither of color types nor in management regarding litter equalization. Conclusions: Results from this study showed an association between the occurrence of pre-weaning diarrhea on mink farms and parity profile, farm size and feeding intensity in the gestational period. The access of dogs to the farm area was a significant risk factor, but needs further clarification. [ABSTRACT FROM AUTHOR]

Control and eradication of Aleutian Mink Disease Virus (AMDV) are a major concern for fur-bearing animal production. Despite notably reducing disease prevalence, current control programs are unable to prevent the reinfection of farms, and environmental AMDV persistence seems to play a major role regarding this issue. In this study 114 samples from different areas and elements of seven infected mink farms were analyzed by qPCR in order to evaluate the environmental distribution of AMDV load. Samples were classified into nine categories, depending on the type of sample and degree of proximity to the animals, the main source of infection. Two different commercial DNA extraction kits were employed in parallel for all samples. qPCR analysis showed 69.3% positive samples with one kit and 81.6% with the other, and significant differences between the two DNA extraction methods were found regarding AMDV DNA recovery. Regarding sample categorization, all categories showed a high percentage of AMDV positive samples (31%–100%). Quantification of positive samples showed a decrease in AMDV load from animal barns to the periphery of the farm. In addition, those elements in direct contact with animals, the street clothes and vehicles of farm workers and personal protective equipment used for sampling showed a high viral load, and statistical analysis revealed significant differences in AMDV load between the first and last categories. These results indicate high environmental contamination of positive farms, which is helpful for future considerations about cleaning and disinfection procedures and biosecurity protocols. [ABSTRACT FROM AUTHOR]

An outbreak of severe pseudorabies virus (PRV) infection in farmed mink occurred in northern China in late 2014, causing significant economic losses in the local fur industry. Here, we report the first case of a PRV outbreak in mink in northeastern China, caused by feeding farmed mink with raw pork or organs contaminated by PRV. Mink infected with virulent PRV exhibited diarrhea, neurologic signs, and higher mortality, which can be misdiagnosed as highly pathogenic mink enteritis virus (MEV), canine distemper virus (CDV), and food poisoning. However, these were excluded as causative agents by PCR or bacteria isolation. The duration of disease was 3-7 days, and the mortality rate was 80-90%. PRV was characterized using indirect immunofluorescence assays (IFA) and electron microscopy (EM). Phylogenetic analysis based on full-length genome sequences and those of individual genes of this novel virus strain showed that it clustered in an independent branch with several other PRV isolates from China. [ABSTRACT FROM AUTHOR]

The optimal timing of separating the mink dam from the litter is suggested to be a balance between the partly conflicting needs of the mother and the kits. Early removal of the dam or partial removal of the litter may protect the dam against exhaustion. Little is, however, known about dam stress and maternal motivation around the time of weaning and separation. Therefore, we investigated effects of separating the dam from the litter using brown first-parity farm mink dams ( n = 374) taken away from the litter either day 49 ± 1 (7w, n = 185) or day 56 ± 1 (8w, n = 189) after birth. The aim was to investigate whether the dams experienced stress/had a different motivation to be reunited with the litter after 7 and 8 weeks, estimated by non-invasive determination of cortisol (FCM: Faecal Cortisol Metabolites) and dam behaviour including calls the first week after separation (D0: Day of removal, D1: next day, D7: seven days after). Supplementary, we evaluated dam body condition (weight, score), nipple activity and health at separation. The two treatment groups had an equal litter size at the time of separation (7w: 5.5 ± 0.17; 8 w: 5.5 ± 0.17 kits; P = 0.76). Likewise, there was no significant difference in dam body weight (7w: 1420 ± 15.0 g, 8w: 1404 ± 14.7, P = 0.43). However, the litter size negatively influenced both the dam weight and body condition ( P < 0.001) regardless of the separation age. Stereotypies D0-D1 were influenced by group (8w > 7w) and increased with number of young ( P < 0.01), indicative of dam hunger/metabolic burden in the preceding period. We found no signs of nipple/inflammation problems, evaluated visually and by Infrared Thermography (IRT) measuring surface temperatures of active teats. Dams separated at litter age 7 weeks had higher concentrations of cortisol metabolites during the first week after removal; i.e. day of separation, D0: 18.8%, D1: 34.5%, D7: 36.9% higher FCM than in 8w dams ( P = 0.014). Likewise, the dam calls increased on the separation day, peaking on the first day after separation (D1). The proportion of dams with calls was higher in the 7w group ( P = 0.024). We interpret these results as a higher maternal motivation in dams at 7 weeks than at 8 weeks after birth. Additionally, the separation-induced calling in dams decreased with increasing litter size ( P = 0.022). Thus in addition to litter age, the size of the litter is important for the maternal motivation. These factors should, therefore, be taken into account for determining the optimal separation time on mink farms. [ABSTRACT FROM AUTHOR]

Hemorrhagic pneumonia caused by Pseudomonas aeruginosa remains one of the most costly infectious diseases among farmed mink and commonly leads to large economic losses during mink production. The objective of this study was to investigate the potential of using phages as a therapy against hemorrhagic pneumonia in mink. A broad-host-range phage from the Podoviridae family, YH30, was isolated using the mink-originating P. aeruginosa (serotype G) D7 strain as a host. The genome of YH30 was 72,192 bp (54.92% G + C), contained 86 open reading frames and lacked regions encoding known virulence factors, integration-related proteins or antibiotic resistance determinants. These characteristics make YH30 eligible for use in phage therapy. The results of a curative treatment experiment demonstrated that a single intranasal administration of YH30 was sufficient to cure hemorrhagic pneumonia in mink. The mean colony count of P. aeruginosa in the blood and lung of YH30-protected mink was less than 10 3 CFU/mL (g) within 24 h of bacterial challenge and ultimately became undetectable, whereas that in unprotected mink reached more than 10 8 CFU/mL (g). Additionally, YH30 dramatically improved the pathological manifestations of lung injury in mink with hemorrhagic pneumonia. Our work demonstrates the potential of phages to treat P. aeruginosa -caused hemorrhagic pneumonia in mink. [ABSTRACT FROM AUTHOR]

The aim of the study was to analyze the effects of the first mating date, age and color variety on the conception rates in farm mink. We analyzed female mink reproductive performance in 492 Sapphire and 463 Standard Black females over 3 or 4 years. The analysis included the number of inefficientmatings, the interval between the first inefficientmating and the efficientmating (copulation) and the conception rates. The results show a significant effect of female's age and color variety on the conception rates. The youngest, yearling females of either color needed a higher number of matings per conception, as compared to older, 2- and 3-year-old females. Black females demonstrated a higher number of inefficient matings (1.066), as compared with Sapphires (0.730). Yearling females were most often mated from 1 to 10 March, and older females from 11 to 20 March. Older females achieved better conception rates than the yearlings. Dates between 11 and 25 March proved to be the optimum for the first mating, since the highest conception rates were observed if the females had mated during this period. [ABSTRACT FROM AUTHOR]

Background: Wounds are regarded as an indicator of reduced welfare in mink production; however, information on the occurrence and significance of wounds is sparse. To provide a basis for assessment and classification of wounds in farmed mink, the distribution pattern and characteristics of wounds in farmed mink in June and October, respectively, is described. A total of 791 and 660 mink from 6 to 12 Danish mink farms, respectively, were examined. The mink were either found dead or were euthanized due to injury or other disease. Mink included from June were kits in the pre-weaning and weaning period (1-2 months old). Mink included from October were juveniles in the late growth period (approximately 5-6 months old) or older. Macroscopic pathology and wound location was systematically recorded. Results: There was considerable variation in morphology as well as location of wounds between June and October. Wounds were primarily located on the front parts of the body and in the head in June (1-2 month old kits) and mainly on the rear parts of the body and on the tail in October (5-6 month old kits and older). Moreover, there were significantly more females than males with wounds for most wound types, and significant differences in occurrence of ear and tail base wounds between certain colour types. Conclusions: Wounds varied significantly from June to October with respect to morphology and anatomical location. Wounds in June were primarily located on the front parts of the body and in the head, while wounds in October were mainly present on the hind parts of the body and on the tail. The majority of the wounds were found in specific well defined skin areas and could therefore be grouped into categories according to anatomical location. [ABSTRACT FROM AUTHOR]

The aim of the study was to explore farmers' perception of stable schools as a tool to improve management for the benefit of mink welfare. Stable schools are knowledge exchange between farmers working towards a common goal, being able to give practical advice to each other. The concept is based on farmer field schools, developed and used in developing countries. Several Danish mink farmers are familiar with erfa-groups which also are farmers meeting, often with an advisor taking part, but the stable schools with only farmers and a facilitator have never been tested on mink farms. In 2013, we therefore established two stable schools with farmers from five Danish mink farms in each group. The meetings were on the respective farms, and every farm was visited once within a year. The host-farmer presented one success story and two challenges he/she wanted to work with and get contributions to from the group. Qualitative interviews were conducted with the farmers to evaluate their perception of stable schools. Based on the results from the study, and results from other studies of stable schools, we can conclude that farmers generally are positive to the structural way of working in stable schools, and that motivation for working towards a common goal is very important for the process of common learning among the farmers. The uniform production system at mink farms gives special challenges in how to work with the different subjects to ensure farmer ownership of the process. The farmers did not see the seasonal production as any constraint, but express that they like to work with the specific problems and challenges related to the respective production periods. [ABSTRACT FROM AUTHOR]

The primary causes of mortality were identified in postmortem examination of 339 (90.9%) of 373 farmed mink (Neovison vison; syn. Mustela vison) from January 2009 through June 2014 at the Utah Veterinary Diagnostic Laboratory (Logan, Utah). Mink were raised under farm conditions in the Intermountain West in North America, except for 1 submission of mink from Wisconsin. In the 339 mink where cause(s) of death were established, 311 (91.7%) died from a single disease or condition, whereas 28 (8.3%) had 2 diseases or conditions contributing to death. Where cause(s) of death were evident, 11 diseases accounted for 321 (94.7%) of the diagnoses: bacterial pneumonia (67, 18.8%), Aleutian mink disease (61, 17.7%), mink viral enteritis (56, 16.2%), hepatic lipidosis (28, 8.1%), nutritional myopathy (24, 7%), bacterial enterocolitis (17, 4.9%), bacterial septicemia (16, 4.6%), starvation (15, 4.3%), epizootic catarrhal gastroenteritis of mink (14, 4.1%), pancreatitis (13, 3.8%), and bacterial metritis (10, 2.9%). In 34 (9.1%) animals, a cause of death was not evident. In an additional 16 (4.3%) of the mink, botulism was suspected from clinical history but could not be confirmed by laboratory testing. Control measures for the most common causes of death in farmed mink include testing and removal of positive animals (Aleutian mink disease), vaccination (Pseudomonas aeruginosa pneumonia, mink viral enteritis), avoidance of obesity in mink (hepatic lipidosis), and environmental management, including maintaining clean water cups, floors, feed troughs, cages, feed silos, feed truck tires, workers’ shoes, dining areas for farm personnel, leather mink handling gloves, street clothes, and coveralls. [ABSTRACT FROM AUTHOR]

Utilization of free-living populations of endangered wildlife species is usually strictly prohibited or restricted. Farming of endangered species can provide products that are in demand as a countermeasure. A novel forensic issue arises because it becomes necessary to discriminate the origin of given wildlife products. We tested the effectiveness of five measurements and four indexes of femur bone using farmed minks ( n = 40) and escapees ( n = 32). Results showed all measurements, namely body mass ( Lf), body length ( Mf), femur mass ( Vf), femur length ( Mb), and femur volume ( Lb), were highly discriminatory. However, they are susceptible to the influence of nutrition level and sex. Femur length index ( Ifl), femur linear density ( Dl), and femur volume density ( Dv) eliminated the influence of level of nutrition and were highly effective. However, Ifl and Dl were influenced by sex ( p = 0.000). Because Dv was not influenced by sex ( p = 0.683) and was highly effective, it was the preferred index. [ABSTRACT FROM AUTHOR]

The article provides information on a study which evaluated the prevalence of Aleutian mink disease virus (AMDV) in the River Otter in sympatry with infected American Mink. Topics covered include the reason the North American river otter may be exposed to AMDV, the ways by which wild mink, or other wildlife, could spread AMDV and the results of the serology and real-time polymerase chain reaction (PCR) conducted on the river otters.

Variations in the contaminant burden in feral and ranch mink, resulting from differences in their diet, may permit the identification of farm escapees. However, this is only possible in the case of contaminants that accumulate to significantly different levels in the two groups of animals. The main objective of this study was to identify chemical markers whose concentrations differ between feral and ranch mink, by analyzing the accumulation of 13 chemical elements in liver and kidney samples. Total mercury levels were up to 15-fold higher in kidney, and up to 7-fold higher in liver of feral mink compared with ranch mink. The majority of feral mink samples analyzed for mercury, contained concentrations that ranged from 1 to 5 μg/g in kidney (68 %) and from 1 to 5 μg/g in liver (70 %). In comparison, the organs of ranch mink had significantly lower levels of mercury: 95 % of kidney samples had concentrations below 1 μg/g and 82 % of liver samples had concentrations below 1 μg/g. Small geographical variations in Hg levels were observed in mink from the four studied feral populations. Significant differences in Cu concentrations between ranch and feral mink were also detected, with low variation within the two groups. Less pronounced differences were recorded for other chemical elements. These data suggest that Hg and Cu may be used as chemical markers for the identification of first generation mink farm escapees. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterise the genetic variability of the Aleutian mink disease virus (AMDV) circulating among mink farmed in Poland and to compare Polish isolates with AMDV variants available in the GenBank database. For this purpose PCR amplification and analysis of the 429 bp DNA fragment of the AMDV NS1 gene from 13 randomly selected AMDV infected mink was performed. A comparison showed that all tested amplicons were closely related to the sequence of the NS1 gene of AMDV and showed high (94%-97%) homology to virus variants from American mink (Neovison vison) isolated in Canada in 2007-2008. Eleven samples showing a high percentage (95%-97%) of sequence similarity together with three similar isolates originating from Canada formed one clade (monophyletic group). Two variants showing a lower percentage (about 94%- 95%) of sequence similarity to isolates from Canada formed a separate clade. Polish viruses can be subdivided into two main groups with a putative ancestor common to both Polish and three Canadian isolates. This result confirms the literature data indicating the occurrence of American mink in Eastern Europe (including Poland) from the 1950s when the animals were imported for breeding purposes. In conclusion, we provide for the first time a report on the genetic characteristics of the AMDV variants circulating in the Polish population of farmed mink and their relationship with previously known AMDV variants isolated and described abroad. [ABSTRACT FROM AUTHOR]

Abstract: Aleutian mink disease virus (AMDV) readily spread within farmed mink and causes chronic infections with significant impacts for welfare and economy. In the present study a currently circulating Danish AMDV strain was used to induce chronic experimental infection of farmed mink. PCR was used to detect viral DNA in full blood, organs, faeces and oro-nasal swabs weekly for the first 8 weeks and then biweekly for another 16 weeks after AMDV challenge inoculation of wild type mink. The mink (n =29) was infected and seroconverted 2–3 weeks after AMDV inoculation and AMDV antibodies persisted during the maximum experimental period of 24 weeks. Viraemia and faecal excretion of viral DNA was detected in the mink (n =29) at various and intermittent time intervals. Excretion of viral DNA in oro-nasal swabs was detected for 1–8 weeks in 21 mink. This highlights the risk of transmitting AMDV between infected farms. PCR was successfully used to detect viral DNA in organs 8, 16 and 24 weeks after AMDV inoculation with only minor differences between these weeks which is of diagnostic interest. This AMDV challenge model was also used to mimic natural infection of susceptible sapphire mink. Four of 6 sapphire mink were infected indirectly via the AMDV inoculated wild type mink whereas the other 2 sapphire mink remained uninfected. [Copyright &y& Elsevier]

The aim of this study was to determine whether farming leads to changes in gastrointestinal function and nitrogen metabolism in farmed mink (FA), as compared with their wild-living counterparts. Three digestibility and balance trials were carried out. Experiment I was performed in May, and experiments II and III were conducted in September 2011. Farmed mink with the standard coat colour were purchased from a production farm in south-eastern Poland. Feral mink were harvested using cages in the hunting grounds of the Polish Hunting Association, Branch in Olsztyn. The experimental materials comprised of the following: trial I - adult males (eight animals per group), trial II - young females (six animals per group), trial III-young animals (five males and five females per group). Food transit time was measured during digestibility trials, on 10 consecutive days. The coefficients of nutrient and energy digestibility and daily nitrogen balance values were compared between groups in each experiment. It was found that farming contributed to changes in gastrointestinal function and nitrogen metabolism in mink. Farmed animals were characterized by a longer bowel transit time, a tendency towards higher nutrient digestibility and higher nitrogen retention, which resulted from selection for higher productivity. [ABSTRACT FROM AUTHOR]

Overall, arable soils in Sweden are currently generally close to phosphorus (P) balance, but excessive P accumulation has occurred on animal fur farms, i.e., those rearing mink ( Mustela vison) and foxes ( Alopex lagopus and Vulpes vulpes). Manure P from these farms has sometimes regarded as sparingly soluble. Laboratory lysimeter topsoil trials with simulated rain demonstrated that potential leaching of P in dissolved reactive form (DRP) can be very high, even for heavy clay (50%-65%) soils. The Swedish/Norwegian soil test P-AL (soil P extracted with acid NH4 lactate, AL) proved useful as a potential indicator of DRP leaching risk (regression coefficient [ R2] = 0.89) from fur farms. The upper 5-cm soil layer, with 190% higher (median) soil P status than the 5-20 cm layer, was the major source of potential DRP leaching through soil columns at the site, despite having been under grass or green fallow for the past 8 y. In percolate from topsoil lysimeters, DRP concentration increased by 0.29 mg L-1 after the long-term manure application but only by 0.14 mg L-1 after the single slurry application when compared to no addition of slurry. Therefore, the build-up to a high soil P status due to the long-term application of mink manure was more important than a single application of pig slurry at a rate corresponding to 22 kg P ha-1 with respect to soil leachate DRP losses in this lysimeter study. The study stresses the importance of precision farming, in which the amount of slurry-P applied is based on testing the already existing soil P content. [ABSTRACT FROM AUTHOR]

Identifying and mapping new sites of establishment of alien species is a research priority as it helps to provide timely management actions. In Italy, feral populations of the American minkNeovison vison,a semi-aquatic mustelid native to North America, have been present since the 1980s in the north of the country and on the island of Sardinia. Recently, mink sightings were reported also in central Italy, in the Lazio region. However, no information existed on the consistency and distribution of this population. The aims of this study were to (1) assess the presence and distribution of the American mink in the Lazio region, (2) identify the possible sources of individuals and (3) provide a evaluation of the efficacy of the different techniques adopted. Data on the distribution of the American mink were obtained during 2008 by gathering bibliographical data, by interviewing the stakeholders, and by carrying out field surveys using camera traps, hair tubes, floating rafts and surveying for signs of presence. Floating rafts proved to be the most successful field method amongst the ones adopted in this study. We recorded the American mink at several sites within the Aniene River catchment and its presence seemed restricted only to this catchment within the Lazio region. We found 12 mink farms in the Lazio region, one of which is still active; occasional escapes or liberations have taken place in 11 of these farms. Given the presence of mink farms and the restricted distribution of the feral mink population in the Lazio region, there are at least two management actions that should be undertaken rapidly: (1) minimising escapes from the remaining mink farm through actions with the farmer and the regional authorities; (2) implementing an eradication program for the Aniene population. [ABSTRACT FROM PUBLISHER]

The American mink (Neovison vison) was introduced to Danish fur farms in the 1930s. An unknown number of mink have managed to escape these farms over the years. Today feral mink are found in the wild in most parts of Denmark. A population viability analysis (PVA) was performed using VORTEX, a stochastic population simulation software, to 1) predict the viability and potential population expansion from different sizes of founding populations of farm escapees, 2) investigate which parameters mostly affect the viability, 3) assess the effects of continuous escapes on the feral populations and how the feral populations are affected by management programs, and 4) discuss eradication strategies and their efficiency in management of the feral American mink population in Denmark. The simulations showed that juvenile mortality had the greatest effect on population viability followed by fecundity, adult mortality, and initial population size. Populations supplemented yearly by escapees all reached the carrying capacity and gained genetic variability over the years. Harvesting was modeled as the yearly number of mink caught in Denmark. Most of the simulated harvested populations crashed within few years after the first harvesting event. This indicates that the feral number of mink in Denmark is sustained due to supplements from mink farms and no true feral population exists. To manage the number of feral mink in Denmark it is essential to prevent escapees. The eradication effort would be most effective if focused on late summer and autumn when juvenile mink leave the maternal territory. [ABSTRACT FROM AUTHOR]

Abstract: Hemorrhagic pneumonia in mink (Neovison vison) is caused by Pseudomonas aeruginosa and is an acute and fatal disease in farmed mink. Earlier work has demonstrated that some outbreaks of hemorrhagic pneumonia are caused by pathogenic strains while most outbreaks are caused by local strains. The objective of this study was to determine the genetic and geographical relationship among outbreaks of hemorrhagic pneumonia by pulsed-field gel electrophoresis typing of P. aeruginosa isolates. Furthermore, chosen isolates were typed by a commercial genotyping method based on single nucleotide polymorphisms (SNPs) and compared to a larger dataset of human and environmental origin. The bacterial isolates were obtained from diagnostic samples from 2002 to 2009 and contained 164 isolates from 95 outbreaks on 90 farms. Our results show that most outbreaks of hemorrhagic pneumonia in mink are caused by distinct strains of P. aeruginosa. We also identified related P. aeruginosa strains which, together with two prevalent but unrelated clones, caused one third of the outbreaks of hemorrhagic pneumonia supporting the sparse literature on this subject. None of the SNP typed strains were identified in a large dataset of human and environmental origin. [Copyright &y& Elsevier]

The genetic diversity of feral and ranch American mink was studied in order to detect gene flux among rivers, investigate the processes of invasion, and determine the possible effects of river barriers. Tissue samples of 78 feral American mink from 5 different river catchments and 18 ranch mink, collected between 2007 and 2011 in Biscay, northern Spain, were genotyped at 21 microsatellite loci. Lack of genetic differentiation of feral mink among the sites and high differentiation between feral and ranch mink was suggested. These results confirm that the mink population established on Butrón River at the beginning of the 1990s may be the origin of almost all the feral mink population within the study area. Additionally, the occurrence of American and European mink was used to analyse the effect of fragmentation on the population viability. The size and composition of the home range of male European mink was considered to model minimum viable units for presence/absence. Forty-two minimum viable units were randomly distributed among rivers in order to analyse the effect of fragmentation on mink occurrence. Barriers were mapped and classified as slight, moderate or absolute, depending on the effect on mink movement, and were introduced into the models. The presence of European and American mink depended on the non-fragmented main river stretches and the number of tributaries free from barriers. Results showed that fragmented rivers can be temporarily occupied but the likelihood of death means that these areas are only sink patches for mink. [ABSTRACT FROM AUTHOR]

Sentinel species are important tools for studies of biodiversity and environmental health. The American mink (Neovison vison) has long been considered a sentinel of environmental contamination, since the species is known to be sensitive to a number of common contaminants, including polychlorinated biphenyls (PCB) and mercury. Mink may not always satisfy an important criterion of sentinels however—that they are continuous residents of the environment being sampled. This is because domestic mink commonly escape from farms, and can be confused with wild mink in areas where mink ranching is prevalent, biasing estimates of environmental contamination taken from free-ranging mink samples. We tested for bias in a sample of free-ranging mink from Ontario, Canada, where both genetic ancestry (domestic, wild, and domestic–wild hybrid) and contaminant burdens (PCBs and mercury) were known. Of 133 mink sampled for both contaminants and genetic ancestry, 9% were determined to be domestic and 10.5% hybrid animals. We found that including domestic and hybrid mink in our analysis resulted in overestimating mean PCB burdens in wild mink by 27%, and underestimating mercury by 13%. We also investigated morphological methods to aid in excluding domestic mink from free-ranging mink samples and found that we had the highest classification success using skull size (condylobasal length), which was 15% and 12% greater in male and female domestic than wild mink, respectively. Given the potential use of mink as sentinels, and also the potential for bias, we recommend that researchers take steps to exclude domestic mink from free-ranging mink samples in studies of environmental health. [Copyright &y& Elsevier]