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1.
The aim of this study was to describe the differences in cranial size and shape that occur between different farmed blue fox populations within and between countries. The skulls were obtained at the pelting time from three Finnish, one Estonian, one Norwegian and seven Canadian farms. The material was subjected to a principal component (PC) analysis for each sex. The first PC-factor explained about 50% of variation. It was identified as the size factor; it discriminated Finnish blue foxes at one end and Nova Scotia foxes at the other end of the scale. The second PC-factor explained about 10% of variation in skull morphology but failed to discriminate the populations. The third factor, which was dominated by interorbital width, discriminated Nova Scotia foxes from the other populations. PC-factor 4 received its highest loading from the length of upper tooth row. This factor differentiated, although poorly, the Newfoundland fox populations, whether local or crosses between the local and the imported Finnish stock, from the others. The sexes were significantly different on most single parameters and the skulls of all farm populations were larger than those of wild Arctic foxes. However, there were also large differences in skull morphology between farms within one country. This shows that farmed blue foxes in different countries have not yet diverged into anatomically distinct populations.  相似文献   

2.
In the autumn of 1968 Pseudorabies was demonstrated in blue foxes (Alopex lagopus) on two fur farms in Jutland. The foxes had been fed with dead piglets from herds of swine belonging to the two farmers.At the same time the disease was diagnosed in piglets from these herds. At the two fur farms there were, respectively, 34 and eight foxes in all; respectively 26 and two died with signs of pruritus. Only few of the surviving foxes had had the opportunity to eat piglets. Eight weeks after the period of disease no antibodies against psedorabies virus could be demonstrated in serum of three surviving foxes.The virus content in various organs of six foxes submitted to the Laboratory was determined by titration in tissue cultures (Table 1).The results indicate that the spreading of virus from the port of entry of the virus to the brain must have occurred by nervous routes.The presence of virus in the tonsils of five of the six foxes and in the nasal mucosa of the sixth one, together with similar results from examination of dogs at this institute would seem to suggest that a transmission of the disease from these carnivores to other animals is possible.Based upon the high virus titers in the medulla oblongata and pons, and with reference to similar results of examination of dogs and to a previous publication on Pseudorabies in Danish red foxes, it is concluded that these tissues must be the material of choice for demonstration of Pseudorabies virus in these carnivores.  相似文献   

3.
The aim of the study was to evaluate semen quality in the two most popular colour morphs of the Arctic fox Alopex lagopus L., blue and white, based on ejaculate parameters, acrosin activity and analysis of sperm morphology. The research material consisted of ejaculates collected once by manual stimulation from 20 one‐year‐old male Arctic foxes (10 individuals of the blue morph and 10 of the white morph). Ejaculates were evaluated in terms of volume, sperm concentration, total number of spermatozoa and the percentage of spermatozoa with major and minor defects. The study revealed that male blue Arctic foxes produce ejaculates with much higher concentration (148.75 × 106/ml) and total number of spermatozoa (98.16 × 106) compared to white Arctic foxes (42.88 × 106/ml and 35.2 × 106 respectively). The level of acrosin activity from white foxes seemed to be higher compared to blue foxes but the difference was not statistically confirmed. Semen from Arctic foxes is characterized by high inter‐individual variability in sperm morphology. The frequency of morphological changes in sperm from Arctic foxes does not significantly depend on ejaculate volume, sperm concentration or the total number of spermatozoa in the ejaculate, but is associated with acrosin activity.  相似文献   

4.
Farming of fur animals represents an important income in Estonia. Even though Trichinella worms does not induce a symptomatic disease in carnivores, the carcasses of skinned animals can increase the biomass of the parasite in the environment, if they are not properly destroyed. The aim of the present survey was to study the prevalence of Trichinella worms in farmed fur animals of Estonia. Of 281 muscle samples from blue foxes (Alopex lagopus), silver foxes (Vulpes vulpes fulva), minks (Mustela vison) and raccoon dogs (Nyctereutes procyonoides), which were collected in eight farms, Trichinella larvae have been detected in 21 animals (8%) from two farms by HCl-pepsin digestion. The highest number of larvae per gram of muscle was found in the front limb muscles. Larvae of the 21 isolates have been identified as Trichinella britovi or Trichinella nativa by a multiplex-PCR analysis.  相似文献   

5.
Parvovirus infections in Finnish fur animals, i.e. ferrets, raccoon dogs, blue foxes and mink, were studied. The ferret was found to be the only insusceptible animal. Parvo enteritis of raccoon dogs, reported since 1980, has spread from East Finland to other parts of the country. A new candidate for the Parvovirus family was found to infect blue foxes. According to serologic investigations, the virus resembled feline panleukopenia virus more than canine parvovirus. Clinical signs during the infection have been mild. Annual vaccination has not eradicated mink enteritis virus on farms, but the disease has taken a subclinical form.  相似文献   

6.
Infection with the intracellular microsporidium Encephalitozoon cuniculi can cause serious disease, encephalitozoonosis, in the blue fox (Alopex lagopus). The disease diagnosis is based on clinical signs and pathological findings, and detection of E. cuniculi or circulating antibodies directed against the parasite. Indirect immunofluorescence (IFAT) and carbon immunoassay (CIA) are the most commonly used serological methods for diagnosis in this species. In the present study, an indirect ELISA (enzyme linked immunosorbent assay) was established and evaluated against IFAT by testing of 205 field samples from blue foxes. There was high agreement between the results of the ELISA and CIA (kappa=0.99), and the ELISA and IFAT (kappa=0.958). There was no significant statistical difference between the tests (p>0.05). It was concluded that the ELISA could be used to identify seropositive farmed blue foxes. The advantage of the ELISA lies in the potential of screening large numbers of animals with the goal of eradicating E. cuniculi infection in the farms.  相似文献   

7.
Serum or body fluid samples of 1,006 foxes were investigated in an ELISA for antibodies against a highly sensitive and specific antigen (Em2-antigen) of Echinococcus multilocularis. Parasitological examinations of the intestines and simultaneous serological examinations were carried out in 505 foxes: A group of 98 blue foxes (Alopex lagopus) from Norwegian fox farms did not contain intestinal stages of E. multilocularis and was clearly sero-negative in Em2-ELISA. On the other hand in red foxes (Vulpes vulpes) originating from European areas known to be endemic for E. multilocularis the following average prevalence rates were found: 244 foxes from Southern Germany, E. multilocularis prevalence 55% and sero-prevalence 60%; 139 foxes from Austria, E. multilocularis prevalence 4% and sero-prevalence 12%. Serological identification of individual foxes with or without intestinal E. multilocularis infection was not possible. Only serological (no parasitological) examination in 402 foxes originating from endemic areas in Switzerland resulted in a sero-prevalence rate of 37%. Sero-prevalence was only 6% and 4% in 54 and 26 other foxes, respectively, originating from Swiss and German areas where E. multilocularis has not yet been reported. Negative control Norwegian (farmed) silver foxes (n = 43) were all sero-negative. The specificity of the Em2-ELISA was confirmed by negative Em2-serologies with sera from dogs infected with intestinal and tissue dwelling helminth species (with the exception of two from 24 dogs infected with E. granulosus).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
Prevalence of Rabies Virus in Foxes Trapped in the Canadian Arctic   总被引:1,自引:1,他引:0       下载免费PDF全文
Brains and salivary glands of 521 trapped arctic foxes (Alopex lagopus) submitted from four different settlement areas in the Northwest Territories were examined for rabies by the standard fluorescent antibody and mouse inoculation tests. Rabies antigen was present in 44 of 201 (21.9%) brains from foxes trapped in the Sachs Harbour area, but submissions from Cambridge Bay (127), Spence Bay (93) and Gjoa Haven (100) were negative. Virus was also present in salivary glands from 43 (97.7%) of these 44 positive foxes.

The arctic fox continues to be the main wildlife reservoir of rabies in the Canadian Arctic and foxes in the prodromal stage of the disease pose a particular threat to the trapper. Preexposure vaccination should always be a consideration in this occupational group.

  相似文献   

9.
OBJECTIVE: To examine the susceptibility of the grey-headed flying fox (Pteropus poliocephalus) to Australian bat lyssavirus (ABL), and to provide preliminary observations on the pathogenesis of the disease in flying foxes. PROCEDURE: Ten flying foxes were inoculated intramuscularly with ABL, and four with a bat-associated rabies virus. Inoculated animals were observed daily, and clinical samples collected every 9 to 14 days. Animals with abnormal clinical signs were euthanased, and samples collected for histological, serological, virological and immunohistological examinations. At 3 months post inoculation (PI), all survivors were euthanased, and each submitted to a similar examination. RESULTS: Three ABL-inoculated flying foxes, and two rabies-inoculated animals developed abnormal clinical signs between 15 and 24 days PI. All three ABL-inoculated animals had histological lesions consistent with a lyssavirus infection, and lyssaviral antigen was identified in the central nervous system (CNS) of each. Virus was isolated from the brain of two affected animals. Of the rabies-inoculated flying foxes, both had histological lesions and viral antigen in the CNS. Virus was recovered from the brain of only one. None of the five affected flying foxes developed anti-lyssavirus antibodies, but, by 3 months PI, five of the seven ABL-inoculated survivors, and one of the two rabies virus-inoculated survivors, had seroconverted. The dynamics of the immune responses were quite variable. CONCLUSIONS: The response of flying foxes to ABL, administered by a peripheral route of inoculation, was similar to that of bats inoculated peripherally with bat-derived rabies viruses.  相似文献   

10.
Sera from 32 foxes sampled at intervals varying from 20 to 70 days after oral inoculation with E. cuniculi spores were tested by the india-ink immunoreaction (IIR) and the indirect fluorescent antibody test (IFAT). Using the IFAT, antibodies were detected at low levels in sera sampled on days 20 and 29 post inoculation, whereas the IIR failed to reveal antibodies in the same sera. In sera sampled from day 35 until day 70 post inoculation, antibodies were detected by both tests, the IIR-titres reaching the magnitude of the IFAT-titres after about 50 days posit inoculation.In 14 sera sampled from foxes of at least 46 days of age and with signs of encephalitozoonosis, the tests gave almost identical results.Comparing IIR- and IFAT-determined antibody titres using E. cuniculi antigens of blue fox and rabbit origin in the test, the antigens seemed to be closely related, supporting the suggestion that the isolates are strains of the same microsporidian species.  相似文献   

11.
Oral immunization of foxes with avirulent rabies virus mutants   总被引:5,自引:0,他引:5  
SAG1, a rabies virus strain bearing one mutation which abolishes virulence for adult animals, was constructed from the SADBern strain of rabies virus which has previously been used as live vaccine for oral immunization of foxes. SAG1 also bears an antigenic mutation which serves as an additional marker of the strain. Studies on mice and four species of wild rodents showed that SAG1 is totally avirulent whereas SADBern is still pathogenic after intracerebral, intramuscular or oral inoculation and thus could cause cases of rabies. Trials of oral vaccination performed on foxes with SAG1 indicate that it is as effective as SADBern. The SAG1 strain represents a significant progress in the search for an efficient and safe live rabies for the oral immunization of wild animals.  相似文献   

12.
Previously described methods for the recovery of intestinal Trichinella worms from rodents are not feasible when applied in larger experimental animals such as foxes. In this study,worm recovery by standard technique of simple incubation of the intestine in saline was compared to embedment of the intestine in an agar gel. The small intestines of Trichinella spiralis infected foxes (4-5 days post inoculation) were slit lengthwise and the two corresponding halves were processed with one of the two incubation methods.Worms were recovered from all samples, and the total worm recovery ranged from 0.2-4.4% of the infection dose. The samples from the standard incubation were very unclear and time consuming to count compared with samples from the agar gel embedment,in which the intestinal debris were kept inside the agar. As the agar gel technique generally yielded higher numbers of worms than the corresponding standard incubation sample, it is with some optimisation, recommended for recovery of intestinal Trichinella worms from foxes.  相似文献   

13.
14.
Ingestion of eggs of the small fox tapeworm, Echinococcus multilocularis, causes the severe human disease alveolar echinococcosis. Previously, the dynamics of the egg excretion from infected carnivores have been studied only where the host animals have been exposed to a single experimental infection. In nature, foxes are most likely repeatedly infected. To study the effect of repeated exposure, twenty-one foxes were inoculated with a high dose of E. multilocularis protoscoleces three times over a 1-month period. For comparative purposes, three groups of twenty-one foxes were respectively inoculated with low, medium, or high single dose of protoscoleces. For each group, worm number and morphology were analyzed after necropsy of seven foxes at 1, 2, and 4 months after last inoculation. The establishment of intestinal worms was very low in all foxes, and surprisingly, most of the worms did not produce eggs. Although most reproductive structures were detectable, the genital pore and the cirrus pouch often had abnormal enlargements that spread internally, most likely preventing the reproductive function. The reason for this abnormality could not be determined, but the preparation and storage conditions of the inoculated protoscoleces may have contributed to the stunted development. Physical stress of E. multilocularis at the larval stage in rodents may later adversely affect the reproductive success of the adult tapeworm in the carnivore definitive host; as in the present study where a worm establishment in the definitive host was only followed by a neglectable egg production.  相似文献   

15.
Encephalitozoon cuniculi causes severe diseases in blue fox puppies. When pregnant vixens are infected, parasites are transmitted over the placenta to the unborn that subsequently develop encephalitozoonosis. Adult foxes themselves do not have signs of disease, but show antibody titres to E. cuniculi. The purpose of the present study was to gain information on the immune response in adult foxes after experimental infection. Sixteen foxes were infected orally with E. cuniculi spores, eight of them twice and 28 days apart. The two groups of animals showed elevated serological values in both the carbon immunoassay and in the ELISA. Elevated serological levels were recorded up to 1 year after the infection took place. The control group (n=8) remained serologically negative throughout the trial. The results of the study showed that blue foxes could be seropositive for at least a year after oral infection with E. cuniculi.  相似文献   

16.
不同锌源对蓝狐生长及肝脏中锌铁含量的影响   总被引:1,自引:0,他引:1  
为了考察在日粮中添加有机锌和无机锌对于蓝狐生长及肝脏中锌铁含量的影响。选取60日龄断乳蓝狐90只,于2007年8月2日~12月27日进行饲养试验。结果表明:在日粮中添加不同锌源的添加剂对于蓝狐生长及肝脏中锌铁含量的影响是不同的。与无机锌组比较,有机锌低剂量组和有机锌高剂量组在整个试验期的平均日增重分别提高了9.62%和12.67%,而且均差异显著(P<0.05);有机锌低剂量组与有机锌高剂量组之间的差异不显著(P>0.05)。有机锌低剂量组和有机锌高剂量组的肝脏中的锌含量比无机锌组分别提高了4.23%、15.15%,其中有机锌高剂量组极显著高于其他试验组(P<0.01),无机锌组与有机锌低剂量组的差异不显著(P>0.05)。有机锌低剂量组和有机锌高剂量组肝脏中铁的含量虽都比无机锌组略有提高,但差异均不显著(P>0.05)。  相似文献   

17.
Rabies first became evident in Canada during the late 18th and early 19th centuries. However, only a few sporadic outbreaks, mainly in domestic animals, were noted before 1945.

Rabies in foxes spread into the Canadian provinces from the Arctic regions during the late 1940s. The disease gradually died out in most areas except Ontario. A second major outbreak, involving skunks, progressed from North Dakota into the Prairie provinces during the late 1950s and 1960s. Today, the major problem areas in Canada with respect to rabies are southern Ontario, which accounts for 85% of the Canadian diagnoses, and the Prairie provinces where rabies is enzootic in skunks.

Rabies is rare in humans in Canada; however more than 40,000 cases have been reported in wild and domestic animals since 1958. Control of rabies is currently being undertaken through vaccination of domestic animals and wildlife, population reduction of wildlife vectors, and human preexposure rabies vaccination.

  相似文献   

18.
Investigations concerning the effect on fur-bearing animals of large doses of vitamin D3 were carried out. The material comprised 62 animals in all--10 silver foxes, 17 blue foxes and 35 mink (Table II). Daily doses of 5 IU vitamin D3/g body weight for two months did not produce clinical symptoms in the foxes. However, a short while after the dose was increased to 10 IU, the animals showed loss of appetite, had difficulty in moving, were apathetic and developed dark coloured faeces. Analysis of blood serum showed markedly raised calcium values (Table III). Calcium deposits were demonstrated in the kidneys and in some cases also in the musculature, gastric mucosa, bronchi and the larger blood vessels. No abnormal signs were shown by 30 mink which received 0.6--0.7 IU vitamin D3/g body weight for five months. PM findings were normal.  相似文献   

19.
There are both positive and negative impacts on wildlife associated with wildlife tourism. In Sweden, the endangered Arctic fox is subject to a growing tourist interest. In the Helags mountain region there are guided Arctic fox safari tours that provide visitors with information about the Arctic fox. A survey of five separate groups of visitors in the region revealed that knowledge about the status of Arctic foxes and awareness of the behavioral guidelines for Arctic fox encounters improved after participation in a safari tour and with increasing Arctic fox interaction. We propose a schematic model summarizing the diverse ways in which wildlife tourism affects wildlife and their relative importance for conservation. The Arctic fox population in Sweden is small and sensitive to disturbance, but the positive impacts of Arctic fox tourism seem to compensate for the negative and contribute to their conservation under the current level of tourism pressure.  相似文献   

20.
An outbreak of foot-and-mouth disease (FMD) in Great Britain was reported on 21 February 2001, followed by an outbreak of FMD in The Netherlands a month later. This Dutch index outbreak occurred on a mixed, veal-calf/dairy-goat farm in Oene, in the central part of The Netherlands. The most-likely route of infection was the import of Irish veal-calves to this Dutch herd via an FMD-contaminated staging point in France. With hindsight, more herds seemed to be infected by the time the index outbreak was confirmed. The regular EU control measures were implemented, in combination with pre-emptive culling of herds within 1km of each outbreak. Nevertheless, more outbreaks of FMD occurred. Most of the virus infections on those farms were "neighborhood infections". Because the situation seemed out of control locally and the destruction capacity became insufficient, it was decided to implement an emergency vaccination strategy for all biungulates in a large area around Oene to stop further spread of the virus. All susceptible animals on approximately 1800 farms in this area were vaccinated. All farms subsequently were depopulated, starting from 2 weeks after vaccination. In total, 26 outbreaks were detected (the last outbreak on 22 April 2001). In total, approximately 260,000 animals were killed.  相似文献   

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