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At least 19 recordsLinked to original sources
PubMed1992

Metabolic rate and evaporative water loss at different ambient temperatures in two species of fox: the red fox (Vulpes vulpes) and the Arctic fox (Alopex lagopus).

1. Resting metabolic rate (RMR) and evaporative water loss (EWL) of adult red and arctic foxes were determined over ambient temperature (Ta) ranges of -13-37 degrees C and -5-30 degrees C as oxygen consumption and amount of water in expired air using an open flow system. 2. The average RMR was 2.60 +/- 0.14 W/kg for the winter red fox, 2.59 +/- 0.14 W/kg for the summer red fox, and 2.35 +/- 0.11 W/kg for the winter arctic fox. 3. The rate of increase of RMR was significant (P less than 0.05) only for Ta range above 27 degrees C. The slopes for this Ta range were 0.152 for the winter red fox, and 0.283 for the winter arctic fox. 4. The upper critical temperature (Tuc) of the red fox is probably between 30 and 32 degrees C. The Tuc of the arctic fox is probably between 26 and 28 degrees C. The lower critical temperatures (Tlc) were not reached. 5. A strong linear relationship between the EWL and Ta was found for Ta range above 27 degrees C. The slopes for this Ta range were 0.523 for the winter red fox, and 1.025 for the winter arctic fox. 6. Probably, there are neither significant intraspecific seasonal nor interspecific differences in the RMR and EWL. The two species seem to differ only in their critical temperatures.

Animals↗
PubMed1992

Diseases and parasites of red foxes, gray foxes, and coyotes from commercial sources selling to fox-chasing enclosures.

Fifty-six red foxes (Vulpes vulpes), 18 gray foxes (Urocyon cinereoargenteus), and 13 coyotes (Canis latrans) obtained by the South Carolina Wildlife and Marine Resources Department during an investigation of suspected illegal wildlife translocation were examined for diseases and parasites. Red foxes and coyotes were confiscated from an animal dealer based in Ohio (USA), and gray foxes were purchased from an animal dealer in Indiana (USA). Emphasis was placed on detection of pathogens representing potential health risks to native wildlife, domestic animals, or humans. All animals were negative for rabies; however, 15 gray foxes were incubating canine distemper at necropsy. Serologic tests disclosed antibodies to canine parvovirus, canine distemper virus, canine adenovirus, canine coronavirus, canine herpesvirus, and canine parainfluenza virus in one or more host species. Twenty-three species of parasites (two protozoans, three trematodes, four cestodes, eleven nematodes, and three arthropods) were found, including species with substantial pathogenic capabilities. Echinococcus multilocularis, a recognized human pathogen not enzootic in the southeastern United States, was found in red foxes. Based on this information, we conclude that the increasingly common practice of wild canid translocation for stocking fox-chasing enclosures poses potential health risks to indigenous wildlife, domestic animals, and humans and, therefore, is biologically hazardous.

Animals↗
PubMed1977

Allelic expression in intergeneric fox hybrids (Alopex lagopus x Vulpes vulpes). II. Erythrocyte glucose-6-phosphate dehydrogenase in Artic and silver foxes: purification and properties.

The functional properties of purified glucose-6-phosphate dehydrogenase (G6PD) from the erythrocytes of Artic foxes (Alopex lagopus) and silver foxes (Vulpes vulpes) were investigated. It was found that pH optima for G6P D range from 8.15 to 8.25 in Arctic foxes and from 10.2 to 10.4 in silver foxes. For G6P, the estimated Km values were 74 X 10(-6) M (at pH 8.2) and 166 X 10(-6) M (at pH 10.2) in Artic foxes and 58 X 10(-6) M (at pH 10.2) and 40 X 10(-6) M (at pH 8.2) in silver foxes. The Km values for NADP were estimated as 62 X 10(-6) M (at pH 8.2) and 86 X 10(-6) M (at pH 10.2) in the Artic foxes and 15 X 10(-6) M (at pH 10.2) and 12 X 10(-6) M (at pH 8.2) in the silver foxes. It was found that Mg2+ ions exert a significant activating effect on G6P D in the Arctic fox and do not affect appreciably its activity in the silver fox. The experimental data indicate that slight differences in the electrophoretic mobility of G6P D are associated with considerable functional differences in this enzyme between the two fox species.

Animals↗
PubMed1976

[Expression of homologous genes in interspecies arctic fox x silver fox hybrids (Alopex lagopus X Vulpes vulpes). III. Mechanisms of expression of alleles of locus GPD, located on the X-chromosome].

The electrophoretic pattern of glucose-6-phosphate dehydrogenase (G-6-PD) was studied in 60 intergeneric fox hybrids (Alopex lagopus X Vulpes vulpes), 33 females and 27 males. It is shown that the structural gene for G-6-PD, designated as Gpd, is located on the X-chromosome in both Arctic and silver foxes. Analysis of G-6-PD in the erythrocytes of hybrid females demonstrated that the phenotypic expression of parental alleles at the locus Gpd varied considerably: from 1:1 to the hemizygous manisfestation of an allele of either the Arctic or silver fox. It is suggested that the variable quantitative expression of the alleles at the locus Gpd in hybrid females is related to the presence of two cell populations having in an active state either the X-chromosome of the Artic or silver fox. It is also assumed that the size of two cell populations is significantly influenced by the different relations in the group of initiator (stem) cells, which possess different X-chromosomes in an active state, which has been established in early embryogenesis. In the case of erythrocytes, it is found that the number of initiator (stem) cells for erythrocytes comprises 5-6.

Alleles↗
PubMed1976

Allelic expression in intergeneric fox hybrids (Alopex lagopus x Vulpes vulpes). I. Comparative electrophoretic studies on blood enzymes and proteins in arctic and silver foxes.

Twenty-seven blood enzymes and proteins, whose structures are presumably controlled by at least 33 genes, were assayed in Arctic and silver foxes by starch gel electrophoresis. Two types of protein and enzyme electrophoretic patterns were distinguished: one exhibiting a single enzyme, the other several isozymes. The two fox species were found to differ in seven of the 27 enzymes and proteins studied: glucose-6-phosphate dehydrogenase, adenylate kinase, erythrocyte carboxylesterase, diaphorase, prealbumin, transferrin, and albumin. No differences were established between the species for the other enzymes and proteins. The data are interpreted as evidence for the existance of a set of enzymes and proteins differentiating the Arctic from the silver fox.

Animals↗
PubMed1975

[Homologous gene expression in intergeneric fox hybrids (Alopex lagopus x Vulpes vulpes). I. Comparative electrophoretic analysis of blood proteins and enzymes in Arctic and silver foxes].

A comparative study of 27 enzymes and proteins in blue and silver foxes was carried out by means of starch gel electrophoresis. The structure of these enzymes and proteins is determined by about 33 genes. It is shown that a number of blood enzymes and proteins of these species is represented by a single electrophoretic form, while lactate dehydrogenase, carboanhydrase, arylesterase, carboxylesterase, diaphorase, hexokinase and tetrasolium oxidase have several forms. It is also found that these species differ in seven enzymes and proteins: diaphorase, G-6-PD, adenylate kinase, carboxylesterase, albumin, prealbumin, transferrins. Other enzymes and proteins are similar in their electrophoretic mobility. The data obtained afford the evidence that the two species (Vulpes vulpes and Alopex lagopus) differ in a set of enzymes and proteins.

Animals↗
PubMed1975

[Variations in blood testosterone levels of prepubertal foxes and during the seasonal genital cycle of the adult male fox (Vupes vulpes) in captivity].

Plasma testosterone levels have been determined by radioimmunoassay on peripheral venous blood samples of young and adult foxes at different times of their genital activity. In the cub, the testosterone levels increase from November to January; at this time, the young is pubescent. In the adult, the testosterone levels are low from April to November. At this time, the levels increase and reach a maximum value from December to February, which is the mating season. Some high testosterone levels observed in summer prove that the endocrine activity of the testis persists during the out-breeding season.

Age Factors↗
PubMed1991

Dietary taurine deficiency and dilated cardiomyopathy in the fox.

Taurine deficiency has been implicated as a potential cause of dilated cardiomyopathy. However, the relationship between taurine and myocardial function is presently unclear. The purpose of this study was to determine whether dilated cardiomyopathy in the fox is associated with dietary taurine deficiency. A total of 68 foxes from farms with a history of death caused by dilated cardiomyopathy and 14 foxes from a farm with no history of dilated cardiomyopathy were studied. Dilated cardiomyopathy was diagnosed by echocardiography in 48% of the foxes from one farm with a positive history and in none of the foxes from the control farm. Foxes less than 9 months of age were more commonly affected than older foxes (p = 0.03). Plasma taurine concentrations were significantly less (p less than 0.01) in foxes that had dilated cardiomyopathy (26.8 +/- 16.4 nmol/ml) than in the control foxes (99.3 +/- 60.2 nmol/ml). A significantly higher (p less than 0.01) incidence of dilated cardiomyopathy was present in foxes with a history of a sibling or offspring that died of dilated cardiomyopathy than in foxes without a family history of cardiac death. In one fox with dilated cardiomyopathy that was tested, the myocardial taurine concentration was lower (1.7 mumol/gm wet weight) than that of control foxes (7.3 +/- 1.6 mumol/gm wet weight). Hepatic cysteinesulfinic acid decarboxylase activity was significantly less (p less than 0.001) in foxes with dilated cardiomyopathy (0.97 +/- 0.2 nmol/mm.mg protein) than in control foxes (2.11 +/- 0.07 nmol CO2/mm.mg protein).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Rabies in urban foxes (Vulpes vulpes) in Britain: the use of a spatial stochastic simulation model to examine the pattern of spread and evaluate the efficacy of different control régimes.

The threat of rabies being reintroduced into Britain is probably greater now than at any time over the last 60 years. This threat is reviewed with particular regard to the problems that would be posed should rabies be introduced to the high-density fox populations found in many cities in southern England. Computer models can provide a valuable means of understanding the pattern of rabies spread in fox populations and the likely problems of control, so the construction of previous rabies models was reviewed. None were found to be suitable for analysing the particular problems posed by high-density, spatially heterogeneous, urban fox populations. Therefore, a new spatial stochastic simulation model was produced, based on demographic and other data collected during a long-term study on the urban fox population in Bristol, and fox density data collected from a number of cities in southern England. The simulation model was used to analyse the effects of spatial heterogeneity in the fox population on the pattern of rabies spread. Simulations were then used to evaluate the effects of: (i) varying levels of fox control; (ii) changing the size of the control zone; (iii) the onset of the rabies epizooty at different times of the year: and (iv) delay before the commencement of control on the chances of containing the disease. These simulations were run for four cities (Bournemouth and Poole, Bristol, Leicester and the West Midlands conurbation) with different mean fox population densities. It was found that the variance in the monthly velocity of the rabies front was greater for heterogeneous fox populations. In cities with high fox densities, low or moderate levels of control were unsuccessful in containing the disease, but these urban areas had the highest rates of success with the highest levels of control. A three-month delay in the commencement of a rabies control campaign on average reduced the chance of successfully controlling the disease by 10-20%, although this was higher in lower-density fox populations. Rabies outbreaks in the dispersal period were on average 10% less likely to be contained. Increasing the size of the control zone increased the chances of successfully containing the disease, although this effect was density dependent, so the effect was less in low-density fox populations. These results are discussed in relation to the current rabies contingency plans for British urban areas.

Animals↗
PubMed1991

Serological (Em2-ELISA) and parasitological examinations of fox populations for Echinococcus multilocularis infections.

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)

Animals↗
PubMed1992

Oral rabies vaccination of arctic foxes (Alopex lagopus) with an attenuated vaccine.

Arctic foxes were immunized with the SAG1 oral rabies vaccine. The effectiveness was determined by the serological response and by the survival to a challenge dose of rabies virus from an Alaskan fox. Vaccine virus was isolated from saliva 1 h after the liquid vaccine was placed directly into the mouth but not subsequently (tested up to 1 week postvaccination). Two weeks after vaccination, protective antibody levels were present in all foxes and all vaccinated foxes survived challenge at 9 weeks postvaccination. At 26 weeks postvaccination (17 weeks postchallenge) all but one fox had detectable antibody levels. Neural tissue harvested from surviving foxes was negative for rabies virus by direct immunofluorescent testing. One of the foxes vaccinated with SAG1 seroconverted and survived challenge even though the titre of the vaccine used was almost 4 logs less than that used to vaccinate the other foxes. These results suggest that the avirulent SAG1 oral rabies vaccine is very effective in protecting arctic foxes.

Administration, Oral↗
PubMed1991

A new type of lesion associated with severe fur damage in Canadian ranch foxes and an investigation of possible causes.

In the silver fox, as in its wild ancestor, the red fox (Vulpes vulpes L.), the annual growing phase (anagen) of guard hair follicles occupies at least four months. Severe damage to the hair coat near the end of this growing period was reported in 1985 on many ranches in New Brunswick and Nova Scotia. A histological analysis of serial sections of skin biopsies showed a marked increase in nuclear aberrations in the hair matrix of anagen guard hair follicles. These nuclear aberrations indicated that cells were undergoing apoptosis, a controlled form of cell death. Tissues from affected and unaffected foxes for histological and toxicological analysis, as well as other data, were obtained during visits to 26 ranches in 1986 and 34 ranches in 1987. Histological sections of the 1987 skin samples showed the mean percentage of nuclear aberrations in 43 unaffected foxes to be 0.08 +/- 0.01 (SEM), while that for 49 affected foxes was 0.51 +/- 0.23. The four foxes with the most severe coat damage also had the highest incidences of guard hair matrix cells with nuclear aberrations, ranging from 20 to 100 times greater than the mean for unaffected foxes. The mitotic index of the hair matrix, which normally remains fairly constant during the hair growth phase, was similar for unaffected and affected foxes (1.83 +/- 0.06 and 1.97 +/- 0.07 respectively). Although our analyses of field data have not established a specific environmental factor associated with increased nuclear aberrations, the possible involvement of toxic agents in follicle damage may warrant further investigation.

Adipose Tissue↗
PubMed1991

[Transmissibility and pathogenicity in the red fox of two rabies viruses isolated at a 10 year interval].

Two rabies virus strains collected from naturally infected foxes in France in 1976 and 1986 were inoculated in 2 groups each consisting of 10 foxes (approximately 50 lethal doses50 mouse intracerebral per fox). Another 20 healthy foxes were kept in the same cages as the inoculated animals in order to study the transmission of both strains. All the inoculated foxes became rabid and transmitted rabies to their cage companion. The intervals between death of the inoculated foxes and death of the cage companion were significantly more variable (P less than 0.001) with the earlier strain, from 1 to 33 days compared to the range obtained with the later strain, 10-14 days. However, the mean intervals did not differ. Epidemiological consequences of such a decrease in variability, if confirmed in the field could decrease the epidemiological extent of rabies. Viremia was demonstrated in 2 foxes inoculated with the later strain but we cannot assume this to be a characteristic of this strain compared with the earlier strain. Rabies virus (both strains) was isolated from the saliva of foxes 29 days or less before the onset of clinical symptoms. This last result raises the question of the time limit as regards security before onset of clinical symptoms in animals involved in human contamination.

Animals↗
PubMed2026

Synaptic Proteome Divergence in the Prefrontal Cortex of Tame and Aggressive Red Foxes (Vulpes vulpes).

The biological mechanisms behind aggressive and affiliative behaviors are difficult to pinpoint. In the Farm-Fox Experiment, conventional foxes were selectively bred since 1959 in two different directions, one for tame and another for aggressive response to humans. The distinct differences in social behavior of tame, aggressive, and conventional populations are genetically based and the three populations live in conditions that control for factors that could impact social reactions, such as environment and social experiences. Genomic and transcriptomic studies of genetic differences among the fox populations have highlighted genes involved in synaptic processes in the prefrontal cortex. To investigate how the synaptic mechanisms differ between the three fox populations, synaptosomes were isolated from prefrontal and premotor cortex extracts of sixteen female foxes. Tandem mass tags with liquid chromatography tandem mass spectrometry (LC-MS) were used to identify and quantify the relative abundance of the proteins. The results were sorted into protein groups and compared between populations using a limma analysis to determine proteins with differential expression (DE). In the tame versus aggressive comparison, 174 protein groups were found to be DE, while only five were found in the conventional versus aggressive comparison. Most DE protein groups had lower fold expression in the aggressive population compared to tame and aggressive populations. ADGRB2 was found to be the most DE protein group, with 11-fold higher expression in aggressive foxes than in tame foxes. ADGRB2 was previously shown to affect depression-like behavior in mice and is involved in the vascular endothelial growth factor signaling pathway, that is known to influence neurogenesis. Enrichment analyses on the DE protein groups found gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways that were enriched in the tame versus aggressive comparison, including multiple, highly enriched terms involving ribosome and translation. Local translation at synapses plays an important role in synaptic plasticity and, as a result, can profoundly influence behavior. This study highlighted potential mechanisms that could underly the behavioral differences between tame and aggressive foxes.

Journal Article↗
PubMed2026

Genome-wide characterization of the FOX gene family reveals sex-biased expression and FoxO-associated regulation during gonadal development in Bellamya aeruginosa.

Forkhead box (FOX) transcription factors are important regulators of development and reproduction, but their roles in molluscan gonadal development remain unclear. In this study, the FOX gene family was systematically identified in the freshwater gastropod Bellamya aeruginosa, and comparative gonadal transcriptomic analyses were performed across sexes and developmental stages.A total of 35 FOX genes were identified and classified into 19 subfamilies. Phylogenetic and synteny analyses indicated that the FOX gene family is generally conserved among mollusks, whereas FoxG and FoxL2 showed lineage-specific expansion. Structural analyses demonstrated that most BaeFOX proteins retained the conserved Forkhead domain architecture. Transcriptomic analyses revealed that gene expression divergence between testes and ovaries was markedly greater than that between developmental stages within the same gonad, indicating that sexual dimorphism is the major source of gonadal transcriptional variation. Functional enrichment consistently identified the FoxO signaling pathway in sex-biased comparisons. Several FOX genes also displayed clear gonad-biased expression patterns, and network analyses suggested that BaeFoxO, BaeFoxL2, and BaeFoxG may play central regulatory roles in gonadal development. These findings provide the first comprehensive characterization of the FOX gene family in B. aeruginosa and suggest that FOX-related regulatory networks potentially participate in gonadal development in gastropod mollusks.

Animals↗
PubMedDate not supplied

The role of foxes Vulpes vulpes in the epidemiology of Echinococcus granulosus in urban environments.

OBJECTIVE: To survey the prevalence of intestinal worms, particularly Echinococcus granulosus, in foxes in Canberra. DESIGN: The locations of foxes seen in Canberra during this study were recorded. Foxes and macropod marsupials killed on the roads of Canberra were collected and examined for the presence of intestinal helminths and hydatid cysts respectively. METHOD: The intestinal contents of the foxes were washed through a fine sieve and examined microscopically. All helminths recovered were collected and identified. All the internal organs of the macropods were examined for any cystic lesions. RESULTS: Forty-five foxes and 44 macropods were examined. Echinococcus granulosus was found in three of the foxes (7%). Hydatid cysts were not found in the internal organs of any of the macropods examined. CONCLUSIONS: Echinococcus granulosus is present in the urban fox population of Canberra. This hitherto unreported aspect of the epidemiology of E. granulosus in Australia could be a potential public health risk to urban populations.

Animals↗
PubMed1991

Prevalence and geographical distribution of the ear canker mite (Otodectes cynotis) among arctic foxes (Alopex lagopus) in Iceland.

Three hundred forty five adult arctic foxes (Alopex lagopus) from all counties in Iceland were examined for excess cerumen and ear canker mites (Otodectes cynotis). Only 13 foxes (4%) from a single county in northwestern Iceland were infested, where the prevalence of otodectiasis was 38%. Whether or not this parasite is new to the arctic fox in Iceland is unknown. If it is recently introduced, possible sources of infestation are farmed silver foxes (Vulpes vulpes), domestic dogs, domestic or feral cats, and arctic foxes from Greenland. It appears that the rate of transmission between adult foxes is low; a more common route of transmission is probably from the mother to her offspring or between vixens breeding in the same dens in subsequent years by contamination of the dens. No correlation was found between the prevalence of mites in foxes and Samson character.

Animals↗