Hormonal induction of oestrus and pregnancy in anoestrous ferrets (Mustela putorius furo)

Three doses of FSH were tested for their ability to induce oestrus in ferrets. A dose of 0.25 mg, administered twice daily, induced oestrus and breeding in most females within 6-13 days. Addition of 5 i.u. hCG during the final stages of follicular development enhanced the percentage of females with implantation sites (85%), and 23% of the ferrets so treated gave birth to kits, none of which survived for more than 3 days. This may have been due to insufficient prolactin secretion and thus inadequate luteal maintenance and milk production, as these females were maintained on a short-day photoperiod.     

Identification of a tyrosinase (TYR) exon 4 deletion in albino ferrets (Mustela putorius furo)

Albinism is due to a lack of pigmentation in hair, skin and eye, and has been shown to occur in several animal species. Mutations of the tyrosinase (TYR) gene account for albinism in domestic cats, rabbits, cattle, mice and rats. In this study, we demonstrate that a TYR mutation accounts for albinism in the ferret (Mustela putorius furo). The coding sequence of the five exons of TYR was determined in genomic DNA from wild-type pigmented 'sable' coloured and albino ferrets. It was not possible to amplify TYR exon 4 in albino ferrets originating from different breeds. The deletion of exon 4 in albino ferrets was confirmed by Southern blot hybridization of genomic DNA from albino and pigmented ferrets. This is the first report of a deletion of a TYR exon in a non-human mammal.     

A panel of microsatellite markers for genetic studies of European polecats (Mustela putorius) and ferrets (Mustela furo)

We report a panel of 12 microsatellite markers, including nine novel polymorphic loci isolated in the European polecat and three loci previously developed in closely related species, for genetic studies of polecats and ferrets. We tested the panel at fine geographic scales in polecat and domestic ferret populations of Britain and Portugal and at a broad geographic scale, using 50 polecat samples from across Western Europe. At the fine geographic scales, we recorded one to five alleles per locus and observed and expected heterozygosities ranging from 0 to 0.80 and from 0 to 0.74, respectively. These values increased markedly in the European sample of polecats. No linkage disequilibrium was detected between any pair of loci and all genotypic frequencies complied with Hardy–Weinberg equilibrium expectations. The microsatellite panel allowed the molecular discrimination of polecats and domestic ferrets in Britain, where hybridisation between the two species has been documented. Thus, these loci may be useful not only in genetic studies of polecats and ferrets but also in studies to assess hybridisation between these two mustelid species.     

Courtship patterns in induced oestrous and natural oestrous domestic ferrets (Mustela putorius furo)

Ten anoestrous female domestic ferrets (Mustela putorius furo) had estrus artificially induced by injection of porcine follicle stimulating hormone. Pre-copulatory activities were defined, quantitatively analyzed, and compared to the pre-copulatory activities of 10 control females placed with the same male ferrets. Lag sequential analysis was used to prepare the behavioral matrices. Matrices were compared with an equality of proportions test. Courtship patterns between the 2 groups did not differ significantly.     

Experimental infection of domestic ferrets (Mustela putorius furo) and Siberian polecats (Mustela eversmanni) with Yersinia pestis

Eight domestic ferrets (Mustela putorius furo) and two Siberian polecats (M. eversmanni) were inoculated subcutaneously with 12 to 1.2 x 10(7) Yersinia pestis originally isolated during an epizootic of plague in white-tailed prairie dogs (Cynomys leucurus) near Meeteetse, Park County, Wyoming (USA) in 1985. None of the ferrets or polecats developed clinical signs of disease which suggested that black-footed ferrets (M. nigripes), a congener, also would be resistant to plague. All animals receiving greater than or equal to 1.2 X 10(3) organisms produced serum antibodies detected by the passive hemagglutination test with titers peaking at 1:1,024 and remaining positive until at least 219 days postinoculation. Sera collected from 12 free-ranging black-footed ferrets near Meeteetse in 1984 and 1985 were negative for antibodies against Y. pestis. Prevalence of antibodies against Y. pestis was high in other carnivores collected from the same area in 1986.     

Characterization of transforming growth factors beta1 and 2 in ferrets (Mustela putorius furo)

Unwanted scar tissue after surgical procedures remains a central problem in medicine. Nowhere is this problem more evident than within the pediatric airway, where excess scarring, termed subglottic stenosis, can compromise breathing. Recent advances in molecular biology have focused on ways to decrease scar formation through understanding of the wound repair process. Transforming growth factor beta (TFGbeta) plays a central role in this pathway. Ferrets serve as an ideal model for the pediatric airway, and reproduction of subglottic stenosis in ferrets is possible. However, ferret cytokine profiles have not been established. In this study, we characterized the presence and nucleotide sequence of the TGFbeta1 and 2 genes in ferrets by using total RNA isolated from airways. Amino acid sequence homology between human and ferret was determined to be 96.6% for TGFbeta1 and 99.3% for TGFbeta2. Given the nearly total homology between TGFbetas of ferret and human origin, the ferret may serve as an ideal model for future molecular studies.     

Experiments and a model examining learning in the area-restricted search behavior of ferrets (Mustela putorius furo)

Area-restricted searches have been described as important componentsof the foraging behavior of many organisms. It is unclear, however,whether individual foragers can use learning to fine-tune theirsearches, or even whether these searches are efficiently performed.I used a simulation model to make qualitative predictions aboutsearch behavior in a laboratory system. The simulation modelindicates that the sinuosity and path length of searches stronglyaffect search efficiency. The model predicts that, for a rate-maximizingforager, path length should increase and search sinuosity shoulddecrease as prey become less clumped. Foraging animals may thereforebe selected to learn the path length and sinuosity of searchesin response to changing degrees of dumping of prey. These predictionswere tested in a laboratory system involving ferrets (Mustelaputorius furo) foraging for oil-drop "prey items." Search pathschanged in a graded manner to experimental manipulations ofthe dumping of prey. As predicted by the model, ferrets learnedto perform longer and less sinuous search paths as prey becameless clumped. This study provides the first evidence that area-restrictedsearch behavior is learned and can be fine-tuned to efficientlyexploit different spatial distributions of food.     

Comparative semen cryopreservation in ferrets (Mustela putorius furo) and pregnancies after laparoscopic intrauterine insemination with frozen-thawed spermatozoa

A study was conducted to determine an optimum technique for semen cryopreservation and the biological competence of frozen-thawed ferret spermatozoa. Fifty-two fresh electroejaculates from 4 males were evaluated for sperm percentage motility, forward progressive motility, motility index (SMI) and acrosomal integrity. To determine the optimum temperature for maintaining sperm motility in vitro and the influence of glycerol on sperm motility, seminal aliquants were diluted in TEST diluent (containing either 0 or 4% glycerol) and maintained at 25 degrees or 37 degrees C. For cryopreservation, semen was diluted in each of 3 cryodiluents (TEST, PDV, BF5F), cooled for 30 min at 5 degrees C and pelleted on solid CO2 or frozen in 0.25 ml straws (20 degrees C/min to -100 degrees C). Following thawing, SMI and acrosomal integrity were determined. Ten females with maximum vulval swelling were given 90 i.u. human chorionic gonadotrophin and laparoscopically inseminated in utero with spermatozoa previously frozen using the optimum diluent and freeze-thaw method. The maintenance temperature of 25 degrees C was superior (P less than 0.05) to 37 degrees C for sustaining sperm motility, and glycerol did not influence (P greater than 0.05) motility for up to 11 h of culture. After thawing, motile spermatozoa were recovered in all treatment groups, but sperm motility and normal acrosomal ratings were highest using the PDV diluent, the pelleting method and thawing at 37 degrees C (P less than 0.05). Seven of the 10 ferrets (70%) inseminated with spermatozoa frozen by this approach became pregnant and produced 31 kits (mean litter size 4.4; range 1-9 kits).(ABSTRACT TRUNCATED AT 250 WORDS)     

Transcervical artificial insemination in the domestic ferret (Mustela putorius furo)

The research was undertaken to develop a successful nonsurgical procedure for artificially inseminating ferrets. A fiberoptic endoscope used in conjunction with a specially designed speculum and catheter permitted cervical catheterization and intrauterine insemination. Sperm were collected from the cauda epididymides of 10 discarded breeder males; the number of sperm in diluted samples used for insemination ranged from 4.4–13.6 × 10⁶/100 μl with progressive motility of sperm ranging from 40 to 60%. Sperm collected from each male were diluted with an egg-yolk extender (TEST) and used to inseminate 8–12 females, with deposition of sperm intravaginally or transcervically into the uterine body 0 or 24 hr after an ovulatory injection of human chorionic gonadotropin (hCG). The vaginal inseminations were used as a control, and no pregnancies resulted after insemination of 26 females. Intrauterine inseminations resulted in 4/24 (17%) of the ferrets pregnant when hCG administration was coincident with insemination, and 19/24 (79%) of the ferrets were pregnant when inseminations were done 24 hr after hCG administration. All inseminated females were euthanized on day 20 after insemination to count fetuses. The mean number of fetuses was 3.1 (range, 1–8). The number (millions) of motile sperm inseminated (X) had a significant effect on the percentage of fetuses (Y). Regression analysis indicated a linear relationship between the two variables, with an R² value of 0.99 and a line of best fit described by the equation Y = 0.029 + 0.034 X. This paper is the first report of transcervical artificial insemination in the domestic ferret (Mustela putorius furo). The method can serve as a model for application to ferrets and other mammals, particularly endangered species. Zoo Biol 17:393–404, 1998. © 1998 Wiley-Liss, Inc.     

Retro-orbital technique for blood collection from the ferret (Mustela putorius furo)

Blood samples were obtained from anesthetized ferrets of various ages, by venipuncture of the retro-orbital plexus with a heparinized capillary pipette. It is recommended that a cumulative collection of 20% of total blood volume not be exceeded for any two week period. This technique, when carefully performed on alternate orbits and at a frequency dictated by body weight and volume of blood needed, has been used repeatedly for months without apparent harm or distress to the animal.     

Dirofilaria immitis: experimental infections in the ferret (Mustela putorius furo)

The ferret, Mustela putorius furo, was found to be susceptible to Dirofilaria immitis infection when exposed to low (14) or high (280-420) numbers of infective larvae harvested from Aedes aegypti. Eight ferrets (half of them cortisonized) were inoculated subcutaneously with 14 larvae each. All of them were subsequently found to harbor D. immitis in the heart, and all but one of them had worms of both sexes. Six of these ferrets were examined for microfilaremia at 31 to 35 weeks after inoculation; 3 were positive (one observed only at postmortem examination) and there was evidence that fertilization of female worms had occurred in one other. Females up to 25.5 cm and males up to 16.0 cm were recovered. There was no evidence that the cortisonization of some ferrets had affected the infections. Both male and female ferrets became infected. Four cortisonized ferrets were inoculated with 280 or 420 larvae of D. immitis (divided equally between subcutaneous and intraperitoneal routes). All of them died 16 to 18 weeks after inoculation, yielding 102 to 125 immature D. immitis. In these lethal infections, worms were recovered from the heart and adjoining vessels, and also from vascular and extravascular sites throughout the body.     

Stages and duration of spermatogenesis in the domestic ferret (Mustela putorius furo)

Classification of seminiferous tubules is the basis for understanding normal and abnormal spermatogenesis. The aim of the present study was to determine spermatogenic stages and the duration of the cycle in the domestic ferret using bromodeoxyuridine (BrdU) as a tracer. Eleven adult male ferrets that were maintained in a breeding condition were used. Testicular sections were stained with the periodic acid-Schiff reaction for light microscopy. To determine the cycle duration, six ferrets were injected intraperitoneally with BrdU, and testes were collected 3h later and 10 days and 3h later. BrdU was detected by immunohistochemistry. Seminiferous tubules were classified into eight stages, and frequencies of stages I-VIII were 10.6, 2.2, 7.9, 13.1, 22.3, 21.9, 14.0 and 8.0%, respectively. The most advanced BrdU-labeled cells at 3h post-injection were leptotene spermatocytes in stage VI and those at 10 days and 3h were pachytene spermatocytes in stage V. From differences in stage frequency and BrdU staining frequency between two time points, the duration of one cycle was estimated to be 13.0 days. The present observations indicate that stages and the cycle duration of the ferret spermatogenesis are similar to those reported in other carnivores.     

The ferret, Mustela putorius furo, as a new species in toxicology.

Comprehensive studies on the haematology, urine chemistry, serum chemistry and gross pathology have been carried out and reported. Seasonal weight changes were confirmed and were initiated, together with sexual activity, when ferrets were brought in to a constant temperature (18-19 degrees C) and 14-hour daylight cycle during the winter months. Levels of haemoglobin, erythrocytes and haematocrit were higher than in most common laboratory species. Similarly, serum electrolytes and glucose levels were higher than in Wistar rats or beagle dogs. Ovaries, uteri and testes displayed a seasonal maturation and atrophy. All other parameters were similar to common laboratory species.     

Reproductive inefficiency in male black-footed ferrets (Mustela nigripes)

The black-footed ferret (Mustela nigripes), once considered extinct, has benefited from captive breeding and subsequent reintroduction into native habitat. A high proportion of females (>90%) exhibit estrus in captivity during the spring breeding season. However, many males considered to be prime-breeding age (1-3 years old) fail to sire offspring. Breeding records in 1995 revealed that 40 of 73 males (55%) managed under the Black-Footed Ferret Species Survival Plan did not reproduce, despite being provided opportunity. The present study was conducted to determine the incidence and etiology of male reproductive failure in 1996 and 1997. In 1996, 38 of 69 (55%) 1- to 3-year-old males failed to sire offspring. Likewise, 35 of 60 (58%) males did not reproduce in 1997. Overall, 21% of adult males failed to sire young in three consecutive breeding seasons (1995-1997). Electroejaculate traits (ejaculate volume, sperm concentration, motility, morphology, and acrosomal integrity) from 29 proven breeder males were not different (P > 0.05) from those of 23 males that did not sire young (nonproven breeders). However, six categories of reproductive failure were identified for the 73 prime-breeding age, nonproven males: 1) underdeveloped testes (22%); 2) improper breeding position with the female (25%); 3) excessive aggression toward estrous females (9%); 4) copulation with no sperm detected at postcoital lavage (19%); 5) copulation with sperm in the vaginal lavage but no resulting pregnancy (18%); and 6) copulation with no vaginal lavage performed and no resulting pregnancy (7%). These data indicate that combined behavioral and physiologic factors, but not overall sperm quality, influence reproductive performance in male black-footed ferrets managed in captivity. Zoo Biol 19:517-528, 2000. Copyright 2000 Wiley-Liss, Inc.     

Effects of Buprenorphine Treatment on Influenza Pathogenesis in the Ferret (Mustela putorius furo)

Ferrets are the gold-standard model for influenza A virus (IAV) research due to their natural susceptibility to human and zoonotic IAV, comparable respiratory anatomy and physiology to humans, and development of clinical signs similar to those seen in infected people. Because the presence and progression of clinical signs can be useful in infectious disease research, uncertainty in how analgesics alter research outcomes or compromise characteristics of disease progression have outweighed the concern regarding animal discomfort from these symptoms. Nonetheless, the principles of animal research require consideration of refinements for this important model for IAV research. Opioids offer a possible refinement option that would not directly affect the inflammatory cascade involved in IAV infection. Mirroring pathogenicity studies that use ferrets, 12 ferrets were inoculated intranasally with the A(H3N2) IAV A/Panama/2007/1999 and divided into 3 treatment groups (n = 4 each), of which 2 groups received buprenorphine treatments on different schedules and the third received a saline control. The duration and location of viral replication, lymphohematopoietic changes, and clinical signs were comparable across all groups at all time points. High quantities of infectious virus in nasal wash specimens were detected in ferrets from all groups through day 5 after inoculation, and peak viral titers from the upper respiratory tract did not differ between ferrets receiving buprenorphine treatments on either schedule. Compared with the saline group, ferrets receiving buprenorphine exhibited transient weight loss and pyrexia, but all groups ultimately achieved similar peaks in both of these measurements. Collectively, these findings support the continued evaluation of buprenorphine as a refinement for IAV-challenged ferrets.

Despite decades of international research and the availability of public health countermeasures, including vaccines and antivirals, influenza viruses remain a persistent threat to human and animal health.^26,35 Influenza A viruses (IAV) exhibit a diverse range of virulence, exist in several host reservoirs, and can show rapid rates of antigenic change.²⁶ As a result, IAV are associated with both seasonal epidemics and occasional pandemics in humans,³⁵ and animal infections with IAV have become key for understanding multifactorial traits that include pathogenicity, transmissibility, and vaccine efficacy. Due to their relatively small size, adaptability to the research setting, and similarities to human lung anatomy and physiology, ferrets provide an excellent model for respiratory diseases in humans and are a valuable small-animal model for such studies.^8,30 Data generated from ferrets are included in numerous risk-assessment rubrics evaluating the pandemic potential of novel and emerging influenza viruses, including those established by the Centers for Disease Control and Prevention and the World Health Organization.^14,51The study of influenza virus in ferrets dates back to the early 1930s, when this species was first found to be susceptible to influenza virus.⁴⁴ Ferrets are naturally susceptible to both human and zoonotic IAV.⁴⁷ After infection, ferrets present with clinical signs like those of humans; these signs are often not recapitulated in other species, such as mice and guinea pigs.^28,39,46 The severity and spectrum of clinical signs associated with influenza virus–inoculated ferrets can vary, depending on the virus strain, route and dose of inoculation, and various host parameters.⁵ Whereas influenza viruses with low virulence in ferrets may cause only acute pyrexia and mild to moderate weight loss, isolates with high virulence can cause severe, systemic illness with gastrointestinal and neurologic symptoms.⁴The 3Rs, replace, reduce, refine, encourage investigation of how research involving animals can be conducted in more humane ways.^2,13,37,41 Analgesia for symptoms of influenza in ferrets represents an opportunity for refinement, but this intervention could confound research assessing disease progression. NSAID and corticosteroids are often prescribed to treat the clinical signs associated with influenza in humans.⁴³ These interventions could alter the inflammatory cascade and subsequent pathophysiology of the disease, thus reducing the validity of studies designed to characterize and compare influenza viruses.^6,43 NSAID reportedly inhibit nuclear factor κB, a regulator of inflammatory processes that is involved in viral RNA synthesis.^25,27 In addition, NSAID have been found to increase survival rates in influenza virus-infected mice.⁵³ Therefore, the use of NSAID may be problematic in studies investigating the pathogenesis of influenza viruses.Buprenorphine, an opioid, is an established analgesic in ferrets that can be administered either intravascularly, intramuscularly, or subcutaneously at 0.01 to 0.05 mg/kg with an analgesic duration of 6 to 12 h.^{11,16,24,38,52} Historically buprenorphine has been described as a partial µ receptor agonist and κ and γ receptor antagonist,^22,29,40,48 but the drug recently was described to behave as a full µ agonist.³⁶ The ceiling effect of analgesia and the immunosuppressive effects reported with other opioids have not been documented to occur with buprenorphine.^15,36,42 However, the use of buprenorphine does have the possibility of adverse effects, including sedation, weight loss, constipation, and respiratory depression.^{10,15,16,22,23,34,42} Nonetheless, buprenorphine is a commonly prescribed analgesic for numerous small mammalian species used in research settings.^20,22,40Given that influenza is an ongoing threat to human and animal health and because no replacement is available for data gained with the ferret model, pain mitigation options for research conducted in this species must be addressed. To date, concerns about altering the course of the disease have precluded the evaluation of refinements options in IAV-infected ferrets. The goal of the current study was to assess the effects of buprenorphine treatments on the pathogenesis of a seasonal IAV in ferrets; this assessment was achieved by comparing virus-inoculated ferrets that were either sham-treated or that received buprenorphine according to 2 different dosing schedules. We hypothesized that buprenorphine treatments would not affect experimental readouts, including morbidity, viral shedding, lymphopenia, and seroconversion in convalescent serum; these parameters are commonly measured during IAV research. Study results indicate that buprenorphine did not uniformly or significantly modulate disease progression, peak viral titers in the upper respiratory tract, or clinical responses used to characterize viral pathogenicity in ferrets.     

Evaluation of iophenoxic acid and rhodamine B for marking feral ferrets (Mustela furo)

Abstract

The blood marker iophenoxic acid, and the fluorescent dye rhodamine B, were evaluated as means of assessing bait consumption in the ferret, Mustela furo. Iophenoxic acid was elevated above baseline concentrations for a minimum of 28 days after dosing, indicating that it is a suitable medium‐term marker. Rhodamine B marked ferrets for a maximum of 7 days, and would therefore have limited operational use with feral ferrets. Iophenoxic acid was used in a field trial to assess the effectiveness of a newly developed baiting strategy for control of wild ferrets. All 21 ferrets captured after field baiting with iophenoxic acid had elevated levels of serum iodine, indicating that the newly developed baiting strategy is highly effective for marking ferrets.     

Immune Response to and Histopathology of Campylobacter jejuni Infection in Ferrets (Mustela putorius furo)

Campylobacter jejuni is 1 of the most common enteric bacterial pathogens worldwide. The mechanisms of pathogenesis remain obscure, in part because of limitations of small animal models. Young ferrets develop diarrhea when fed C. jejuni, but their pathology and the immune response after infection have not been examined in detail. In the present study, we examined the pathogenesis of C. jejuni CG8421 and associated immune responses in ferrets. After oral infection with C. jejuni CG8421, 86.7% of the animals developed diarrhea and inflammatory responses that were similar to those seen in human infection. Pronounced histopathologic changes in the colonic mucosa of infected animals were observed during the acute phase (days 1 through 3) of infection. Electron micrographs of colonic epithelium revealed disruption of the villi and internalized bacteria that were not within membrane vacuoles. During the acute phase, C. jejuni was isolated from the livers of 7 of 9 (78%) animals, and bacteria were visualized immunohistochemically in the livers from 5 of the 7 animals (71%) from which C. jejuni was isolated. A vigorous systemic and mucosal immune response to Campylobacter antigens was elicited after infection of ferrets. The data presented contribute to the current knowledge of the pathogenicity of and immunologic response to C. jejuni CG8421 in ferrets and better understanding of this model.Abbreviation: ASC, antibody-secreting cellsCampylobacter jejuni are gram-negative, spiral, microaerophilic, motile bacteria and 1 of the most common enteric bacterial pathogens globally.^15,20 The annual incidence of C. jejuni diarrheal disease varies geographically, ranging from sporadic infections in young adults in developed countries²⁸ to as frequent as 40,000 per 100,000 among children living in hyperendemic regions.¹⁵ In addition, C. jejuni is the primary cause of ‘traveler''s diarrhea’ in various regions of the world.^39,41,44 The clinical disease of C. jejuni infection has a wide spectrum of symptoms, varying from a mild, transient watery diarrhea to a bloody diarrhea with severe abdominal cramps and fever. C. jejuni infection also is associated with development of Guillain–Barré syndrome.⁵¹ Most strains of C. jejuni contain lipooligosaccharides that mimic human gangliosides structurally. Antibodies against these lipooligosaccharide structures lead to an autoimmune response, resulting in Guillain–Barré syndrome.⁵²Despite extensive study, little is understood about the mechanism by which C. jejuni causes diarrheal disease. Various Campylobacter small animal models have been reported, but these require surgical manipulation,^13,46 administration of chemicals or antibiotics (or both),^17,26,30 or inoculation by an unnatural route.⁵ None of these published models incorporate the natural route of infection. Although several immunodeficient mouse models have been reported,^35,36,49 the applicability of these models for studying the pathogenesis and immune response of natural infection is limited. An adult mouse lung model has been described that may be useful for studying pathogenesis and inflammatory response and acquired immunity, but the route of infection is not the same as that in humans.^1,5 Unlike other small animals, naïve ferrets (younger than 11 wk) intragastrically inoculated with C. jejuni developed mild to moderate diarrhea with mucus, fecal leukocytes or frank blood that lasted for as long as 3 d and remained colonized for as long as 8 d.^9,10,18 Moreover, on rechallenge with the homologous bacterial strain, ferrets asymptomatically excreted C. jejuni in their stools.¹⁰ The observation of resistance to disease, but not to infection, is similar to findings from human studies, in which protection against disease developed before colonization resistance.¹¹ Ferrets have been used to evaluate vaccines against C. jejuni¹⁴ and in molecular pathogenesis studies using strain 81-176 to confirm a role in virulence for capsular polysaccharide and flagellar glycans.^3,21 However, we evaluated the histopathology and immune response after C. jejuni infection in ferrets in more detail in the present study.C. jejuni CG8421 was isolated from a case of dysentery in Thailand. It has an lipooligosaccharide core that, as shown by chemical analyses, lacks all ganglioside mimicry.³⁸ The absence of ganglioside mimicry is predicted to reduce the risk of Guillain–Barré syndrome. We selected strain CG8421 for the current studies as part of an evaluation of a potential strain for use in future human vaccine challenge studies. Here we report the pathogenesis, histopathology, inflammatory, and immune responses after oral infection of ferrets with C. jejuni strain CG8421.     

Factors affecting the efficiency of embryo transfer in the domestic ferret (Mustela putorius furo)

Embryo transfer (ET) to recipient females is a foundational strategy for a number of assisted reproductive technologies, including cloning by somatic cell nuclear transfer. In an attempt to develop efficient ET in domestic ferrets, factors affecting development of transferred embryo were investigated. Unilateral and bilateral transfer of zygotes or blastocysts in the oviduct or uterus was evaluated in recipient nulliparous or primiparous females. Developing fetuses were collected from recipient animals 21 days post-copulation and examined. The percentage of fetal formation was different (P<0.05) for unilateral and bilateral transfer of zygotes (71%) in nulliparous females with bilateral transfer (56%) in primiparous recipients. The percentage (90%) of fetal formation in nulliparous recipients following unilateral transfer of blastocysts was higher (P<0.05) than that observed in primiparous recipients with bilateral ET (73%). Notably, the percentage of fetal formation was higher (P<0.05) when blastocyts were transferred as compared to zygotes (90% versus 71%). Transuterine migration of embryos occurred following all unilateral transfers and also in approximately 50% of bilateral transfers with different number of embryos in each uterine horn. These data will help to facilitate the development of assisted reproductive strategies in the ferret and could lead to the use of this species for modeling human disease and for conservation of the endangered Mustelidae species such as black-footed ferret and European mink.     

Macroscopic and roentgenographic anatomy of the skull of the ferret (Mustela putorius furo)

Normal macroscopic and roentgenographic features of the skull of the ferret (Mustela putorius furo) were examined and described. Data were based on a sample of 100 (50 male and 50 female) adult ferrets of known body weight and age. The skull was described macroscopically according to six standard views, i.e. dorsal, lateral, ventral, caudal, cranial and midsagittal. The mandible was described separately. The roentgenographic characteristics of the ferret skull were demonstrated only in lateral and dorsoventral projections. Furthermore, the skull length and width as well as the minimum frontal width were measured, and skull indices were derived from relevant measurements. Sexual dimorphism was examined both morphologically and craniometrically. Besides the common features of a carnivore skull, the ferret skull is relatively elongated and flat with a short facial region. The skulls of adult male ferrets are about 17% longer and 22% wider than those of the females. Significant sexual dimorphism also exists regarding certain skull indices. The general features and some dimensional parameters of the adult ferret skull support the contention that the ferret would be an interesting and workable alternative animal model in craniofacial research.