Ferret Research Articles

A Meta-Analysis of Rhesus Macaques (Macaca mulatta), Cynomolgus Macaques (Macaca fascicularis), African green monkeys (Chlorocebus aethiops), and Ferrets (Mustela putorius furo) as Large Animal Models for COVID-19.

Animal models are at the forefront of biomedical research for studies of viral transmission, vaccines, and pathogenesis, yet the need for an ideal large animal model for COVID-19 remains. We used a meta-analysis to evaluate published data relevant to this need. Our literature survey contained 22 studies with data relevant to the incidence of common COVID-19 symptoms in rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), African green monkeys (Chlorocebus aethiops), and ferrets (Mustela putorius furo). Rhesus macaques had leukocytosis on Day 1 after inoculation and pneumonia on Days 7 and 14 after inoculation, in frequencies that were similar enough to humans to reject the null hypothesis of a Fisher exact test. However, the differences in overall presentation of disease were too different from that of humans to successfully identify any of these 4 species as an ideal large animal of COVID-19. The greatest limitation to the current study is a lack of standardization in experimentation and reporting. To expand our understanding of the pathology of COVID-19 and evalu- ate vaccine immunogenicity, we must extend the unprecedented collaboration that has arisen in the study of COVID-19 to include standardization of animal-based research in an effort to find the optimal animal model.

Reverse zoonosis of coronavirus disease-19: Present status and the control by one health approach.

The recent coronavirus disease (COVID-19) outbreak is one of its kind in the history of public health that has created a major global threat. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a zoonotic source and hence, reverse zoonosis (disease transmission from humans to animals) increases the risk and rate of SARS-CoV-2 infection. Serological and molecular analyses and experimental infection studies have identified SARS-CoV-2 infection in several animal species in various countries. Different domestic and wild animals, including cats, dogs, tigers, lions, puma, snow leopard, minks, and pet ferrets, are infected naturally with SARS-CoV-2, mostly through suspected human to animal transmission. In addition, in vivo experimental inoculation studies have reported the susceptibility of cats, ferrets, hamsters, Egyptian fruit bats, and non-human primates to the virus. These experimentally infected species are found to be capable of virus transmission to co-housed animals of the same species. However, SARS-CoV-2 showed poor replication in livestock species such as pigs, chickens, and ducks with no detection of viral RNA after the animals were deliberately inoculated with the virus or exposed to the infected animals. As the pets/companion animals are more susceptible to COVID-19, the infection in animals needs an in-depth and careful study to avoid any future transmissions. The one health approach is the best inter-disciplinary method to understand the consequences of viral spread and prevention in novel host populations for the betterment of public health. Further in this review, we will explain in detail the different natural and experimentally induced cases of human to animal SARS-CoV-2 infection.

Persistent negative stakeholder perspectives limit recovery of a critically endangered carnivore

AbstractThe human component in endangered species conservation has the potential to significantly limit the ability to achieve recovery of these species globally. Across the Great Plains of North America there have been significant declines in populations of several grassland‐obligate species, including the black‐tailed prairie dog (Cynomys ludovicianus) and the critically endangered black‐footed ferret (Mustela nigripes). Social surveys conducted in Montana, USA, 27 years ago, immediately prior to reintroduction of black‐footed ferrets, described widely differing attitudes and knowledge among stakeholder groups—with most local and state residents being opposed to conservation and recovery of these two wildlife species. We conducted a mail survey replicating methods of the 1993 study to assess current attitudes and knowledge concerning prairie dogs and black‐footed ferrets among five stakeholder groups (local and statewide ranchers, urban and local residents, and members of conservation organizations). Our results demonstrate that despite concerted outreach efforts and a general rise in knowledge about black‐footed ferrets and prairie dogs across stakeholder groups, similar differences in attitudes persisted among stakeholder groups over time, with local stakeholders adjacent to recovery sites maintaining the most negative attitudes. We also observed that local stakeholders supported a significantly shorter time threshold (<10 years) for abandoning efforts to restore an endangered species should recovery goals not be met. Given the reliance on local public support for conserving these species, and other endangered species globally, our findings highlight the importance of continually reassessing stakeholder attitudes and knowledge over time to assess challenges and identify opportunities for endangered species restoration.

Construction and Implementation of Carbon Fiber Microelectrode Arrays for Chronic and Acute <em>In Vivo</em> Recordings

This protocol describes a procedure for constructing carbon fiber microelectrode arrays for chronic and acute in vivo electrophysiological recordings in mouse (Mus musculus) and ferret (Mustela putorius furo) from multiple brain regions. Each step, following the purchase of raw carbon fibers to microelectrode array implantation, is described in detail, with emphasis on microelectrode array construction.

Differential susceptibility of SARS-CoV-2 in animals: Evidence of ACE2 host receptor distribution in companion animals, livestock and wildlife by immunohistochemical characterisation.

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 ACE2 expression in a number of species which will enable further understanding of host susceptibility and tissue tropism of ACE2 receptor‐mediated viral infection.

Identifying Behavioural Traits and Underlying Personality Dimensions in Domestic Ferrets (Mustela putorius furo).

Simple SummaryPersonality research is lacking in the domestic ferret (Mustela putorius furo). The fundamental objective of this study was thus to investigate the underlying structure of personality in ferrets. Owner-reported trait ratings were collected using an online questionnaire, which entailed ferret owners rating several traits (adjectives) on a Likert scale, according to how well they applied to their ferret(s). Four key personality dimensions emerged and were labelled Extraversion, Sociability, Attentiveness, and Neuroticism, according to the types of traits they were composed of. Certain characteristics were found to influence personality: male ferrets were rated as more sociable than females, whereas females were rated as more attentive and neurotic. Extraversion generally decreases with age, and de-sexing was insignificant across all personality dimensions. These results are beneficial for informing the discussion concerning the evolutionary significance of animal personality as well as providing aid in positive welfare management, that is, catering to the needs of individuals rather than groups.The aim of this study was to examine the personality structure of domestic ferrets (Mustela putorius furo) by using owner-based reporting of personality traits. A total of 743 ferret owners participated in an online questionnaire, with a total of 1029 ferrets being assessed. Respondents rated 67 adjectives based on their ferret(s) behavioural traits and personality. Principal component analysis (PCA) of these trait ratings identified four underlying personality dimensions, which accounted for 47.1% of the total variance. These were labelled according to the traits that they encompass: Extraversion, Sociability, Attentiveness, and Neuroticism. Details about ferret sex, de-sexing status, age, and coat colour were also sought, and General Linear Mixed Models were used to test the main effects of these characteristics on the personality dimensions. It was found that sex (p < 0.01) and age (p < 0.001) significantly influenced certain personality components, whereas de-sexing did not. Sociability, Attentiveness, and Neuroticism were found to differ based on sex, whereby males were rated as more sociable than females, but females were rated higher on the Attentiveness and Neuroticism subscales. Finally, Extraversion was found to generally decrease with age. We can use the findings of this study to make cross-species comparisons and further inform the discussion regarding the adaptive relevance of animal personality. Identifying differences in personality types can improve welfare by using this information to satisfy the different needs of individuals.

Antibodies to Leishmania in naturally exposed domestic ferrets (Mustela putorius furo) in Spain

Zoonotic leishmaniosis due to Leishmania infantum is a vector-borne disease endemic in southern Europe and dogs are the main reservoir for this infection. Seasonal variations in antibody titers in this species in areas where phlebotomine vectors have seasonal patterns of activity are important for epidemiological, preventive and clinical studies related with canine leishmaniosis. It has been suggested that cats, rabbits and ferrets may act as peridomestic reservoirs and not only as accidental hosts. The aim of this study was to determine if seropositive ferrets (Mustela putorius furo) to Leishmania could be affected by seasonal variations of anti-Leishmania antibodies. A group of seropositive clinically healthy ferrets (n = 21) were included in this study. A significant reduction in anti-Leishmania infantum antibodies was detected during non-transmission period (December 2020-February 2021) in comparison to transmission period (April-October 2020). This study describes for the first time a seasonal variation in the anti-Leishmania antibodies detected in domestic ferrets following natural exposure during sand fly transmission period and the following non-sand fly transmission period in a Mediterranean area considered as an area where L. infantum is endemic.

Biodetection of a specific odor signature in mallard feces associated with infection by low pathogenic avian influenza A virus.

Outbreaks of avian influenza virus (AIV) infection included the spread of highly pathogenic AIV in commercial poultry and backyard flocks in the spring of 2015. This resulted in estimated losses of more than $8.5 million from federal government expenditures, $1.6 billion from direct losses to produces arising from destroyed turkey and chicken egg production, and economy-wide indirect costs of $3.3 billion from impacts on retailers and the food service industries. Additionally, these outbreaks resulted in the death or depopulation of nearly 50 million domestic birds. Domesticated male ferrets (Mustela putorius furo) were trained to display a specific conditioned behavior (i.e. active scratch alert) in response to feces from AIV-infected mallards in comparison to feces from healthy ducks. In order to establish that ferrets were identifying samples based on odors associated with infection, additional experiments controlled for potentially confounding effects, such as: individual duck identity, housing and feed, inoculation concentration, and day of sample collection (post-infection). A final experiment revealed that trained ferrets could detect AIV infection status even in the presence of samples from mallards inoculated with Newcastle disease virus or infectious laryngotracheitis virus. These results indicate that mammalian biodetectors are capable of discriminating the specific odors emitted from the feces of non-infected versus AIV infected mallards, suggesting that the health status of waterfowl can be evaluated non-invasively for AIV infection via monitoring of volatile fecal metabolites. Furthermore, in situ monitoring using trained biodetectors may be an effective tool for assessing population health.

Status of Sperm Functionality Assessment in Wildlife Species: From Fish to Primates.

Simple SummaryIn general, wildlife species have been underrepresented, in terms of understanding their reproductive physiology. The artificial propagation of wildlife species, found in aquaculture (e.g., fish) and in protection of endangered species (e.g., black-footed ferret), is pertinent to this discussion. One important approach to addressing this would involve a basic understanding of the structure and function of the gametes of many wildlife species. The focus of this investigation was to provide a better understanding of the physiology of sperm of diverse wildlife species, with special attention given to the assessment of high-quality sperm. Modern approaches using sophisticated microscopy (image analysis) techniques, e.g., computer-aided sperm analysis and sperm flagellar analysis, provided advanced technology to evaluate sperm quality quantitatively. Some of these techniques involved largely automated assessments of many aspects of sperm motility, morphology, vitality, fragmentation and other indirect methods. These modern assessments are fundamental to classify sperm quality. Accordingly, cutting-edge technologies used to define high quality sperm of representative species from most vertebrate animal groups (from fish to primates) were discussed in the present work. These approaches are also important in developing and assessing the best methods to cryopreserve sperm for assisted reproductive technologies in wildlife species.(1) Background: in order to propagate wildlife species (covering the whole spectrum from species suitable for aquaculture to endangered species), it is important to have a good understanding of the quality of their sperm, oocytes and embryos. While sperm quality analyses have mainly used manual assessment in the past, such manual estimations are subjective and largely unreliable. Accordingly, quantitative and cutting-edge approaches are required to assess the various aspects of sperm quality. The purpose of this investigation was to illustrate the latest technology used in quantitative evaluation of sperm quality and the required cut-off points to distinguish the differential grades of fertility potential in a wide range of vertebrate species. (2) Methods: computer-aided sperm analysis (CASA) with an emphasis on sperm motility, 3D tracking and flagellar and sperm tracking analysis (FAST), as well as quantitative assessment of sperm morphology, vitality, acrosome status, fragmentation and many other complimentary technologies. (3) Results: Assessing sperm quality revealed a great deal of species specificity. For example, in freshwater fish like trout, sperm swam in a typical tight helical pattern, but in seawater species sperm motility was more progressive. In amphibian species, sperm velocity was slow, in contrast with some bird species (e.g., ostrich). Meanwhile, in African elephant and some antelope species, fast progressive sperm was evident. In most species, there was a high percentage of morphologically normal sperm, but generally, low percentages were observed for motility, vitality and normal morphology evident in monogamous species. (4) Conclusions: Sperm quality assessment using quantitative methodologies such as CASA motility, FAST analysis, morphology and vitality, as well as more progressive methodologies, assisted in better defining sperm quality—specifically, sperm functionality of high-quality sperm. This approach will assist in the propagation of wildlife species.

Follow Up on Simple (Closed) Extraction of Fractured Maxillary Canine Teeth in Domestic Ferrets (Mustela putorius furo).

Fractured canine teeth (especially maxillary canine teeth) are common in domestic ferrets (Mustela putorius furo). We evaluated (detailed oral/dental and radiographic examination under general anesthesia) 18 domestic ferrets affected by 23 complicated crown fractures of periodontally healthy permanent maxillary canine teeth over a 2-year period. Average age of the ferrets at the time of diagnosis was 2.6 years. Only three teeth were discolored on clinical examination. Out of 23 teeth, 22 were radiographically evaluated. No radiographic evidence of endodontic disease was observed in 11/22 canine teeth. Inflammatory root resorption was observed in 5/22, periapical lucency in 5/22 teeth, apical widening of periodontal ligament space in 6/22 teeth, and failure of the pulp cavity to narrow in 3/22 teeth. All animals were treated by simple (closed) extraction of the affected teeth. Histological examination of eight teeth was performed. Pulp appeared histologically vital in five (3/5 showed no radiographic evidence of endodontic disease), pulpitis was diagnosed in two (both without radiographic evidence of endodontic disease) and pulp necrosis in one case (dental radiographs revealed apical widening of periodontal ligament space and failure of the pulp cavity to narrow). All extraction sites healed uneventfully by the 2-week recheck examination. Long-term follow-up revealed development of post-extraction upper lip entrapment with mandibular canine tooth in eight out of 18 ferrets, which appeared clinically irrelevant. According to clients seven out of 18 ferrets showed an improved quality of life. Simple tooth extractions are warranted in ferrets affected by complicated crown fracture of the periodontally healthy permanent maxillary canine teeth.

Aggressive behaviour of Hodgkin's-like lymphoma in a domestic ferret

A 3-year-old castrated male ferret was suspected to have lymphoma based on a markedly enlarged mesenteric lymph node. Hodgkin’s-like lymphoma (HLL) was suspected because numerous Reed-Sternberg-like cells were observed in the fine-needle aspiration biopsy of the mesenteric lymph node. In the post-mortem histopathology, neoplastic cells were invasively proliferated not only in the mesenteric lymph nodes, but also in the liver and spleen. Immunohistochemically, most neoplastic cells were positive for vimentin and BLA-36, weakly positive for CD20, and negative for Pax5, CD79a, CD3, CD45, and Iba-1, demonstrating similarity to human Hodgkin’s lymphoma (HL). In addition, a prominent programmed cell death protein 1 (PD-1) expression was observed at the sites showing malignant tumour proliferation. HLL in non-human beings can be morphologically and immunophenotypically similar to human HL, but the prognosis and clinical outcome may differ. This is the first study analysing the PD-1 expression in a ferret, suggesting that PD-1 can be a novel diagnostic and prognostic factor in a similar manner to humans.

Establishment of an induced pluripotent stem cell line from a female domestic ferret (Mustela putorius furo) with an X chromosome instability

The domestic ferret (ferret; Mustela putorius furo) is an important animal model for neuroscience and preclinical/veterinary medicine owing to its highly developed cerebral cortex and susceptibility to avian influenza and corona viruses. Nevertheless, there is a lack of in vitro ferret models, since immortal cell lines including induced pluripotent stem cells (iPSCs) of ferrets have been scarce. In this study, we established an iPSC line from ferret skin fibroblasts. The established iPSC line, fiPS-1, showed standard characteristics of pluripotency, but its X chromosome was unstable. Collectively, the present study provides a useful resource for in vitro model using the ferret.

Comparison of plasma total solids concentration as measured by refractometry and plasma total protein concentration as measured by biuret assay in pet rabbits and ferrets

To determine the agreement between plasma total solids (TS) concentration as measured by refractometry and plasma total protein (TP) concentration as measured by biuret assay in pet rabbits and ferrets. 253 and 146 blood samples from 146 and 121 ferrets and rabbits, respectively, with results of CBC and plasma biochemical analyses. Data were collected from medical records regarding plasma TS and TP concentrations, PCV, plasma biochemical values, plasma appearance, and patient signalment. Agreement was determined between refractometer and biuret assay (reference method) values for plasma TS and TP concentration. Other variables were examined for an impact on this agreement. Mean ± SD plasma TP and TS concentrations were 6.4 ± 0.8 mg/dL and 6.6 ± 0.8 mg/dL, respectively, for rabbits and 6.3 ± 1.2 mg/dL and 6.4 ± 1.1 mg/dL for ferrets. On average, refractometer values overestimated plasma TP concentrations as measured by biuret assay. Plasma cholesterol, glucose, and BUN concentrations and hemolysis and lipemia had significant effects on this bias for ferrets; only BUN concentration had an effect on bias for rabbits given the available data. Other variables had no influence on bias. The limits of agreement were wider than the total allowable analytic error, and > 5% of the data points were outside acceptance limits, indicating that the 2 methods were not in clinical agreement. Refractometer measurements of plasma TS concentration failed to provide a good estimation of biuret assay measurements of plasma TP concentration in rabbits and ferrets, suggesting that these 2 analytic methods and the results they yield cannot be used interchangeably in these species.

The Ferret as a Model System for Neocortex Development and Evolution

The neocortex is the largest part of the cerebral cortex and a key structure involved in human behavior and cognition. Comparison of neocortex development across mammals reveals that the proliferative capacity of neural stem and progenitor cells and the length of the neurogenic period are essential for regulating neocortex size and complexity, which in turn are thought to be instrumental for the increased cognitive abilities in humans. The domesticated ferret, Mustela putorius furo, is an important animal model in neurodevelopment for its complex postnatal cortical folding, its long period of forebrain development and its accessibility to genetic manipulation in vivo. Here, we discuss the molecular, cellular, and histological features that make this small gyrencephalic carnivore a suitable animal model to study the physiological and pathological mechanisms for the development of an expanded neocortex. We particularly focus on the mechanisms of neural stem cell proliferation, neuronal differentiation, cortical folding, visual system development, and neurodevelopmental pathologies. We further discuss the technological advances that have enabled the genetic manipulation of the ferret in vivo. Finally, we compare the features of neocortex development in the ferret with those of other model organisms.

An ethical analysis of cloning for genetic rescue: Case study of the black-footed ferret

Genetic rescue is a management tool used to decrease genetic load and increase fitness. The technique relies on the addition of unique genomes into a population's gene pool, but when no living candidates are available for translocation, preserved genetic resources may be an option. Biobanks are a source of cryopreserved material, including fibroblasts which have the potential to be used as source genetic material, but would require the use of cloning to create a living individual with the desired genome. An ethical analysis of this emerging technology in conservation is necessary to help determine when cloning is justified and to identify issues that need to be addressed in order that the management action is approached responsibly. We provide a framework for ethical analysis of conservation cloning for genetic rescue by considering the goals, means and desirability of conservation cloning. We then conduct a preliminary analysis of the use of conservation cloning for the genetic rescue of an endangered species, the black-footed ferret (Mustela nigripes), as a case study. The analysis generates several recommendations for moving toward ethically responsible introduction of cloning into black-footed ferret recovery efforts.

Host barriers to SARS-CoV-2 demonstrated by ferrets in a high-exposure domestic setting

Ferrets (Mustela putorius furo) are mustelids of special relevance to laboratory studies of respiratory viruses and have been shown to be susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and onward transmission. Here, we report the results of a natural experiment where 29 ferrets in one home had prolonged, direct contact and constant environmental exposure to two humans with symptomatic disease, one of whom was confirmed positive for SARS-CoV-2. We observed no evidence of SARS-CoV-2 transmission from humans to ferrets based on viral and antibody assays. To better understand this discrepancy in experimental and natural infection in ferrets, we compared SARS-CoV-2 sequences from natural and experimental mustelid infections and identified two surface glycoprotein Spike (S) mutations associated with mustelids. While we found evidence that angiotensin-converting enzyme II provides a weak host barrier, one mutation only seen in ferrets is located in the novel S1/S2 cleavage site and is computationally predicted to decrease furin cleavage efficiency. These data support the idea that host factors interacting with the novel S1/S2 cleavage site may be a barrier in ferret SARS-CoV-2 susceptibility and that domestic ferrets are at low risk of natural infection from currently circulating SARS-CoV-2. We propose two mechanistically grounded hypotheses for mustelid host adaptation of SARS-CoV-2, with possible effects that require additional investigation.

A retrospective study (2006-2020) of cytology and biopsy findings in pet rabbits (Oryctolagus cuniculus), ferrets (Mustela putorius furo) and four-toed hedgehogs (Atelerix albiventris) seen at an exotic animal clinic in Tokyo, Japan

ABSTRACT Background: Rabbits, ferrets, and four-toed hedgehogs are popular exotic pets, but comprehensive epidemiological studies in these animals have been rarely conducted. The present study aims to clarify the incidence of neoplastic and non-neoplastic diseases in pet rabbits, ferrets and four-toed hedgehogs in Japan. Methods: We histologically/cytologically investigated 1098 samples from 883 rabbits, 812 samples from 521 ferrets and 561 samples from 468 four-toed hedgehogs that were collected at Miwa Exotic Animal Hospital and submitted to the Laboratory of Veterinary Pathology, The University of Tokyo between 2006 and 2020. The examinations of necropsy samples were not included in the present study. Results: Of the 1098 samples from diseased rabbits, 721 (65.7%) were diagnosed as neoplastic and 377 (34.3%) were as non-neoplastic. Uterine adenocarcinoma (21.1%), cutaneous soft tissue sarcoma (15.1%) and mammary gland adenocarcinoma (8.2%) were the most commonly encountered neoplasms. Endometrial hyperplasia (35.8%), testicular atrophy (4.2%) and uterine adenomyosis (3.7%) were the most common non-neoplastic lesions in rabbits. Of the 812 samples from diseased ferrets, 487 (60.0%) were diagnosed as neoplastic and 325 (40.0%) were as non-neoplastic. Adrenocortical tumor (23.2%), lymphoma (19.3%) and pancreatic islet cell tumor (11.5%) were the most commonly encountered neoplasms. Extramedullary hematopoiesis in the spleen (10.5%), lymph node hyperplasia (7.7%) and cholangiohepatitis (4.6%) were the most common non-neoplastic lesions in ferrets. Of the 561 samples from diseased hedgehogs, 338 (60.2%) were diagnosed as neoplastic and 223 (39.8%) were as non-neoplastic. Endometrial stromal tumor and endometrial mixed tumor (23.7%), oral squamous cell carcinoma (13.0%) and cutaneous soft tissue sarcoma (11.5%) were the most commonly encountered neoplasms. Gingivitis/stomatitis (39.5%), endometrial hyperplasia (18.8%) and dermatitis (6.7%) were the most common non-neoplastic lesions in hedgehogs. Conclusions and clinical relevance: Information obtained from the present study will provide a useful reference for veterinarians working with these exotic animals. Based on the literature search, this is the largest-scale retrospective study on disease incidence in hedgehogs.

Echocardiographic measurements in clinically healthy ferrets without sedation

Cardiac diseases, predominantly acquired diseases such as valvular insufficiency and cardiomyopathies, are a common problem in domestic ferrets. Aim of the present study was to establish body-weight related echocardiographic reference intervals for standard B- and M-mode parameters, especially of the left atrium, in clinically healthy ferrets without sedation. Eighteen client-owned healthy, non-sedated ferrets underwent echocardiography in right lateral recumbency. Mean values were calculated from the evaluation of 3 cardiac cycles with good wall differentiation within 3 M-mode measurements in the right parasternal long axis view (level of the chordae tendinae, tip of the mitral valve and level of the aortic root and left atrium). Additionally, measurements of the left atrium (LA) and aorta (Ao) were performed in the short axis view at the level of the aorta and the LA/Ao ratio was calculated. The 9 neutered male and 9 neutered female ferrets had a mean age of 2.6 ± 1.3 years and a mean body weight of 1.04 ± 0.31 kg. M-mode measurements of the left ventricle and the aortic root were possible in all animals. Body weight exerted a significant effect on the ventricular dimensions in diastole and systole as well as on the measurements of the left atrium and the aorta. In the B-mode evaluations, measurements of the aorta and the left atrium were frequently only performable on a static image. A significant effect of body weight on the dimensions of both aorta and left atrium were also apparent in the B-mode measurements. Calculated values such as fractional shorting and LA/Ao-ratio proved to be independent of body weight. Standard B- and M- parameters may be used in routine examinations in order to evaluate cardiac morphology in the non-sedated ferret. Consideration of the body weight is warranted in this species.

Mucosal Challenge Ferret Models of Ebola Virus Disease.

Recent studies have shown the domestic ferret (Mustela putorius furo) to be a promising small animal model for the study of Ebola virus (EBOV) disease and medical countermeasure evaluation. To date, most studies have focused on traditional challenge routes, predominantly intramuscular and intranasal administration. Here, we present results from a non-clinical pathogenicity study examining oronasal, oral, and ocular mucosal challenge routes in ferrets. Animals were challenged with 1, 10, or 100 plaque forming units EBOV followed by monitoring of disease progression and biosampling. Ferrets administered virus via oronasal and oral routes met euthanasia criteria due to advanced disease 5–10 days post-challenge. Conversely, all ferrets dosed via the ocular route survived until the scheduled study termination 28-day post-challenge. In animals that succumbed to disease, a dose/route response was not observed; increases in disease severity, febrile responses, serum and tissue viral load, alterations in clinical pathology, and gross/histopathology findings were similar between subjects. Disease progression in ferrets challenged via ocular administration was unremarkable throughout the study period. Results from this study further support the ferret as a model for EBOV disease following oral and nasal mucosa exposure.

SARS-CoV-2 Seroprevalence in Household Domestic Ferrets (Mustela putorius furo).

Simple SummaryAnimal infections with SARS-CoV-2 have been reported in different countries and several animal species have been proven to be susceptible to infection with SARS-CoV-2 both naturally or by experimental infection. Moreover, infections under natural conditions in more than 20 mink farms have been reported where humans could have been the source of infection for minks. However, little information is available about the susceptibility of pet animals under natural conditions and currently there is no SARS-CoV-2 epidemiological assessment occurrence in household ferrets. In this study, the presence of SARS-CoV-2 antibodies was evaluated in serum samples obtained from 127 household ferrets (Mustela putorius furo) in the Province of Valencia (Spain). Two ferrets tested positive to SARS-CoV-2 (1.57%) by in-house enzyme-linked immunosorbent assay based on receptor binding domain (RBD) of Spike antigen. Furthermore, anti-RBD SARS-CoV-2 antibodies persisted at detectable levels in a seropositive SARS-CoV-2 domestic ferret beyond 129 days since the first-time antibodies were detected. This study reports for the first time the evidence of household pet ferrets exposure to SARS-CoV-2 in Spain to date.Animal infections with SARS-CoV-2 have been reported in different countries and several animal species have been proven to be susceptible to infection with SARS-CoV-2 both naturally and by experimental infection. Moreover, infections under natural conditions in more than 20 mink farms have been reported where humans could have been the source of infection for minks. However, little information is available about the susceptibility of pet animals under natural conditions and currently there is no SARS-CoV-2 epidemiological assessment occurrence in household ferrets. In this study, the presence of SARS-CoV-2 antibodies was evaluated in serum samples obtained from 127 household ferrets (Mustela putorius furo) in the Province of Valencia (Spain). Two ferrets tested positive to SARS-CoV-2 (1.57%) by in-house enzyme-linked immunosorbent assay based on receptor binding domain (RBD) of Spike antigen. Furthermore, anti-RBD SARS-CoV-2 antibodies persisted at detectable levels in a seropositive SARS-CoV-2 domestic ferret beyond 129 days since the first time antibodies were detected. This study reports for the first time the evidence of household pet ferrets exposure to SARS-CoV-2 in Spain to date.