Pathology of naturally acquired Angiostrongylus vasorum infection in the red fox (Vulpes vulpes)

199 out of 509 foxes culled in a rabies control scheme, were shown to be infected with the metastrongylid parasite Angiostrongylus vasorum. Pathological lesions associated with angiostrongylosis in the fox are described and compared to reported lesions of A. vasorum infection in the dog. The lesions observed in the foxes seemed to be less severe and mainly confined to the ventral parts of the lung lobes which showed granulomatous pneumonia. Right ventricular hypertrophy of the heart was present in all infected foxes. It is believed that the fox population represents an important reservoir of A. vasorum.     

Helminth fauna of the red fox (Vulpes vulpes Linnaeus, 1758) in southern Belarus

We examined 94 carcasses of and 1,213 faecal samples from red foxes collected between 1981 and 2001 in natural and transformed ecosystems in the southern part of Belarus. A total of 32 helminth species were found. Of these, the most common were Alaria alata, Pearsonema plica, Taenia crassiceps, Toxocara canis, Trichinella spp. larvae and Uncinaria stenocephala. All species are significant for medical and veterinary health.     

First report of Trichinella pseudospiralis in Poland, in red foxes (Vulpes vulpes)

Nematode worms of the genus Trichinella are one of the most widespread zoonotic pathogens. Natural transmission between hosts can only occur through the ingestion of infected meat. To date, two Trichinella species are known to be etiological agents of disease among domestic animals and wildlife in Poland: T. spiralis and T. britovi. In the last decades, since the administration of an oral vaccination against rabies, the red fox population in Poland has increased exponentially. The study area covers the Nowy Targ region: a mountainous area (585–1138 m above the sea) in southern Poland. Of 24 red foxes examined in the study, four were infected with Trichinella isolates: three were identified as T. britovi and one as T. pseudospiralis. The muscle of red foxes infected with T. britovi harboured 2.75, 3.11, 4.4 LPG and with T. pseudospiralis 0.36 LPG. Trichinella larvae were identified at species level by genomic and mitochondrial multiplex PCR, the products of which were sequenced for comparison with other sequences available in GenBank. The sequences obtained from the Polish T. pseudospiralis isolate, deposited in GenBank under the accession numbers JQ809660.1 and JQ809661.1, matched sequences already published in GenBank. Sequence comparison showed a 100% match with the large subunit ribosomal RNA gene of T. pseudospiralis isolate ISS 013, and a 96–95% match with those of T. pseudospiralis isolates ISS 141 and ISS 470. This is the first report of the identification of T. pseudospiralis larvae from red fox in Poland.     

Helminth fauna of the red fox (Vulpes vulpes Linnaeus, 1758) in southern Belarus

We examined 94 carcasses of and 1,213 faecal samples from red foxes collected between 1981 and 2001 in natural and transformed ecosystems in the southern part of Belarus. A total of 32 helminth species were found. Of these, the most common were Alaria alata, Pearsonema plica, Taenia crassiceps, Toxocara canis, Trichinella spp. larvae and Uncinaria stenocephala. All species are significant for medical and veterinary health.     

The vomeronasal organ of wild canids: the fox (Vulpes vulpes) as a model

The vomeronasal system (VNS) has been extensively studied within specific animal families, such as Rodentia. However, the study of the VNS in other families, such as Canidae, has long been neglected. Among canids, the vomeronasal organ (VNO) has only been studied in detail in the dog, and no studies have examined the morphofunctional or immunohistochemical characteristics of the VNS in wild canids, which is surprising, given the well-known importance of chemical senses for the dog and fox and the likelihood that the VNS plays roles in the socio-reproductive physiology and behaviours of these species. In addition, characterising the fox VNS could contribute to a better understanding of the domestication process that occurred in the dog, as the fox would represent the first wild canid to be studied in depth. Therefore, the aim of this study was to analyze the morphological and immunohistochemical characteristics of the fox VNO. Tissue dissection and microdissection techniques were employed, followed by general and specific histological staining techniques, including with immunohistochemical and lectin-histochemical labelling strategies, using antibodies against olfactory marker protein (OMP), growth-associated protein 43 (GAP-43), calbindin (CB), calretinin (CR), α-tubulin, Gαo, and Gαi2 proteins, to highlight the specific features of the VNO in the fox. This study found significant differences in the VNS between the fox and the dog, particularly concerning the expression of Gαi2 and Gαo proteins, which were associated with the expression of the type 1 vomeronasal receptors (V1R) and type 2 vomeronasal receptors (V2R), respectively, in the vomeronasal epithelium. Both are immunopositive in foxes, as opposed to the dog, which only expresses Gαi2. This finding suggests that the fox possesses a well-developed VNO and supports the hypothesis that a profound transformation in the VNS is associated with domestication in the canid family. Furthermore, the unique features identified in the fox VNO confirm the necessity of studying the VNS system in different species to better comprehend specific phylogenetic aspects of the VNS.     

Trichinella sp. in red foxes (Vulpes vulpes) from Catalonia, NE Spain

European legislation allows the official recognition of Trichinella-free pig holdings, provided Trichinella sp. infection is absent from humans and prevalence of Trichinella sp. infection in red foxes (Vulpes vulpes) is below 0.1% in the area, region or country. Tibialis anterior muscle samples from 1,319 red foxes captured in Catalonia (NE Spain) between 1998 and 2007 were analyzed for Trichinella sp. using the digestion method. Four foxes resulted positive (one in 1999, one in 2002 and two in 2006), accounting for a low prevalence (0.3%). However, this prevalence was concentrated in mountain or rural areas with a low sample size, reaching high local prevalences. The two positive samples in 2006 were characterized as Trichinella britovi, and a sylvatic cycle of trichinellosis seems to occur, at least in the rural insufficiently sampled regions of Catalonia. Overall, the results obtained do not currently allow the establishment of Trichinella-free pig holdings in the study area, but further research is needed to better know the prevalence and cycle of Trichinella sp. in Catalonia.     

Specific detection of Echinococcus spp. from the Tibetan fox (Vulpes ferrilata) and the red fox (V. vulpes) using copro-DNA PCR analysis

There are three Echinococcus species, Echinococcus granulosus, E. multilocularis, and E. shiquicus, which are distributed on the vast area of pastureland on the eastern Tibetan plateau in China. Tibetan foxes (Vulpes ferrilata) have been determined to be the main wild definitive host of E. multilocularis and E. shiquicus, but little information is available on the prevalence of these two parasites in Tibetan foxes. Consequently, the copro-prevalence of these parasites in foxes from the eastern Tibetan plateau was evaluated in this study. For each copro-DNA sample extracted from fox feces, a 133-bp segment of EgG1 Hae III was used to screen for infection with E. granulosus. Multiplex nested polymerase chain reaction (PCR) analysis was used to target an 874-bp segment of the mitochondrial COI gene to distinguish E. multilocularis and E. shiquicus. Among 184 fecal samples, 120 were from Tibetan foxes and six from red foxes (Vulpes vulpes). Of the fecal samples from Tibetan foxes, 74 (giving a copro-prevalence of 62?%) showed the presence of Echinococcus spp.: 23 (19?%) were found to contain E. multilocularis, 32 (27?%) E. shiquicus, and 19 (16?%) showed mixed infection with both E. multilocularis and E. shiquicus. Two fecal samples from red foxes were found to be infected with E. multilocularis. No fox feces were found to be infected with E. granulosus. Tests on zinc finger protein genes and a 105-bp fragment of the Sry gene found no significant difference in the prevalence of the two parasites between sexes. The efficiency of our multiplex nested PCR methods were compared with previous polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) methods and some problems associated with the copro-PCR were discussed.     

Comparative behavioral effects between synthetic 2,4,5-trimethylthiazoline (TMT) and the odor of natural fox (Vulpes vulpes) feces in mice

Synthetic 2,4,5-trimethylthiazoline (TMT)--a component of red fox (Vulpes vulpes) feces--is frequently used to induce unconditioned fear in rodents. Surprisingly, direct comparison between TMT and natural fox feces odor is almost nonexistent. In this study, Experiment 1 compared the avoidance in relation to TMT concentration, natural fox feces, and gender of fox and mice. Results show that the avoidance is (a) higher with either pure or 50% TMT as compared to natural fox feces, whereas the difference is slight with 10% TMT, and (b) significantly higher for the female mouse group compared to the male mouse group with TMT as well as natural fox feces. In addition, no clear difference in effect was observed between male and female fox feces. Experiment 2 compared behavioral parameters recorded as an index of fear and anxiety, general activity, and avoidance in elevated plus-maze and open-field chamber between 10% TMT and natural fox feces in relation to the estrus cycle of the mice. Results show no cycle period effect--except for the avoidance parameter "distance to odorant"--and no different effects between 10% TMT and natural fox feces except for freezing.     

High prevalence of Capillaria plica infections in red foxes (Vulpes vulpes) in Southern Germany

The nematode Capillaria plica is an ubiquitous parasite of the urinary tract of Canidae and Felidae. It causes a wide spectrum of clinical symptoms, ranging from asymptomatic infections to urinary bladder inflammation, pollacisuria, dysuria, and hematuria. Foxes serve as reservoir hosts and are considered to be a potential source of infection for companion and hunting dogs as well as domestic cats which acquire the infection by ingestion of earthworms which are the intermediate hosts. Despite its importance, epidemiological studies on this parasite are scarce and almost entirely lacking altogether for Central Europe. Therefore, we examined 116 red foxes (Vulpes vulpes) for the infection of C. plica by pathologic examination of the urinary bladders and microscopy of mucosal smears and urine sediments. The parasite was detected in 90 (78%; 95% CI, 68.9–84.8%) of the foxes, originating from all administrative districts of Bavaria (Southern Germany). Since Bavaria is characterized by a high number of forests and wildlife sanctuaries that provide ideal living conditions for foxes, the corresponding risk of infection of companion and hunting dogs by oral ingestion of earthworms as the intermediate hosts can likewise not be excluded. Because of the scarcity of reports on prevalences of C. plica worldwide, we also include a brief review of the available literature.     

Molecular evidence of kobuviruses in free-ranging red foxes (Vulpes vulpes)

Red foxes (Vulpes vulpes) are susceptible to viral diseases of domestic carnivores. In this study, by screening rectal swabs collected from 34 red foxes in Italy, we identified kobuvirus RNA in five samples. Based on analysis of partial RdRp and full-length VP1 genes, all of the strains shared the highest identity with canine kobuviruses (CaKVs) recently detected in the US, the UK and Italy. These findings provide the first evidence of the circulation of these novel viruses in foxes.     

Epidemiology of alveolar echinococcosis in France. 1. Intestinal helminths in the red fox (Vulpes vulpes L.) from Haute-Savoie

In the course of an epidemiological survey concerning the alveolar echinococcosis and its causative agent, Echinococcus multilocularis, the autopsies of 150 wild red foxes captured in the department of the Haute-Savoie between December 1983 and August 1988 disclosed 139 cases of intestinal helminthiasis with cestodes and nematodes; no trematode was found. Multiple infections were frequent. The cestoda recorded consist of the following species: Taenia crassiceps: 44 cases (29%); Echinococcus multilocularis: 34 cases (23%); Taenia polyacantha: 22 cases (14%); Mesocestoides litteratus: 7 cases (4.6%); Amoebotaenia paradoxa: 1 case (0.6%). The Nematoda concerned are: Uncinaria stenocephala: 79 cases (52%); Toxocara canis: 67 cases (44%); Toxascaris leonina: 16 cases (10%); Trichuris vulpis: 12 cases (8%); Pterygodermatites affinis: 8 cases (5%); Trichostrongyloidea sp.: 5 cases (3%). The animals were not examined for Trichinella spiralis. The results are compared with those observed anteriorly in the province of Auvergne (France).     

Intestinal helminth communities of the red fox (<Emphasis Type="Italic">Vulpes vulpes</Emphasis> L.) in the Italian Alps

The study analyses the intestinal helminth communities found in 645 red foxes of alpine populations from five areas of Northern Italy. In particular, the aim was to evaluate the contribution of both environmental variability and the structure of fox population (extrinsic and intrinsic factors, respectively) in shaping the structure and composition of the intestinal helminth communities. To identify the influence of the characteristics of the host (i.e. age and sex) together with extrinsic factors (year, site, season, and altitude of collection) on number of species, total load per fox, prevalence and abundance of each parasite species, general linear models were performed. Fifteen helminth species have been detected in the intestine of 545 infected animals (84.5%) with a total of 17,144 parasites collected. The analysis of factors influencing both prevalence and abundance of infection of the parasite species revealed the preponderance of extrinsic factors on intrinsic ones. In particular, geographical areas influenced prevalence and abundance of every parasite species, showing high spatial variability. The lower influence of host factors may suggest that, in this case, host dynamics play a trivial role with respect to spatial variability in determining parasite abundance. These results pointed out high prevalence of intestinal helminth infections in the Italian Alpine fox, confirmed the typical composition of parasite fauna within fox populations, underlined local differences in the structure and composition of the helminth communities. Moreover, this study highlights the major role of extrinsic factors vs intrinsic ones.     

Occurrence of Echinococcus multilocularis (Cestoda, Taeniidae) in red foxes (Vulpes vulpes) from Western Ukraine

Echinococcus multilocularis was found for the first time in red foxes in the L’vivska and Volynska regions (Western Ukraine). Prevalence was 36% and intensity was 11–731 parasites. The material was identified as E. multilocularis on morphological characters. It is presumed that this infection of foxes with E. multilocularis occurred locally and, probably, can be considered as a consequence of the expansion of the range of the parasite.     

Serological evidence of infection with Ehrlichia spp. in red foxes (Vulpes vulpes) in Switzerland

Serum samples from 1,550 red foxes in Switzerland were tested for antibodies to the agents of canine granulocytic and monocytic ehrlichiosis by an indirect immunofluorescent technique. Forty-four (2.8%) of the samples were positive for Ehrlichia phagocytophila, which is an antigen marker for granulocytic ehrlichiosis. In contrast, none of the samples had antibodies specific to Ehrlichia canis, the agent of monocytic ehrlichiosis.