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.     

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.     

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.     

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.     

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.     

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.     

In contrast to dogs, red foxes (Vulpes vulpes) did not shed Neospora caninum upon feeding of intermediate host tissues

To clarify whether red foxes (Vulpes vulpes) can be final hosts of Neospora caninum, foxes and dogs were fed in parallel on tissues of a sheep and a goat experimentally infected with N. caninum. The faeces of at least two of five dogs contained N. caninum oocysts, as determined by bioassay. In the faeces of all six foxes fed in parallel, oocysts were detected that were larger in size (length 12.6 +/- 0.5 microm, width 11.8 +/- 0.4 microm) than the oocysts shed by the dogs. Ribosomal RNA sequences and the results of an immunoblot-based bioassay provided further evidence that these oocysts were different from N. caninum. A titration experiment performed to determine the sensitivity of a bioassay utilising gerbils showed that as few as five sporulated N. caninum oocysts could be detected by this test. This indicates that, in two feeding experiments, less than 3,700 and 200 sporulated N. caninum oocysts, respectively, could have been among the Hammondia sp.-like oocysts collected from fox faeces. These results suggest that the red fox is either an inappropriate final host for N. caninum or not at all a final host for this parasite.     

The first report of Angiostrongylus vasorum (Nematoda; Metastrongyloidea) in Poland,in red foxes (Vulpes vulpes)

Angiostrongylus vasorum belongs to the superfamily of Metastrongyloidea. This nematode occurs in foxes, dogs and other predators. The Nematode A. vasorum place themselves in the pulmonary artery and its branches, and in the right ventricle and atrium of the heart. Numerous species of land snails are the intermediate hosts of the parasite. In 2013, lungs and hearts of 76 foxes shot in the Forest District G??boki Bród in Augustowska Primeval Forest were parasitologically necropsied. Four of the examined foxes were infected with the nematode A. vasorum, a prevalence of 5.2%. In one fox pericardium there were 6 male and 6 female nematodes. In the remaining three foxes nematodes were localized in the pulmonary artery. In two foxes 2 specimens of nematodes were detected (male and female, and two females) while 1 female was detected in the other fox. This is the first report of the presence of the nematode A. vasorum in fox in Poland.     

Analysis of vaccine-virus-associated rabies cases in red foxes (Vulpes vulpes) after oral rabies vaccination campaigns in Germany and Austria

To eradicate rabies in foxes, almost 97 million oral rabies vaccine baits have been distributed in Germany and Austria since 1983 and 1986, respectively. Since 2007, no terrestrial cases have been reported in either country. The most widely used oral rabies vaccine viruses in these countries were SAD (Street Alabama Dufferin) strains, e.g. SAD B19 (53.2%) and SAD P5/88 (44.5%). In this paper, we describe six possible vaccine-virus-associated rabies cases in red foxes (Vulpes vulpes) detected during post-vaccination surveillance from 2001 to 2006, involving two different vaccines and different batches. Compared to prototypic vaccine strains, full-genome sequencing revealed between 1 and 5 single nucleotide alterations in the L gene in 5 of 6 SAD isolates, resulting in up to two amino acid substitutions. However, experimental infection of juvenile foxes showed that those mutations had no influence on pathogenicity. The cases described here, coming from geographically widely separated regions, do not represent a spatial cluster. More importantly, enhanced surveillance showed that the vaccine viruses involved did not become established in the red fox population. It seems that the number of reported vaccine virus-associated rabies cases is determined predominantly by the intensity of surveillance after the oral rabies vaccination campaign and not by the selection of strains.

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On the facial artery of the raccoon dog (Nyctereutes procyonoides viverrinus Temminck).

Detailed observations were made of the facial artery in 20 raccoon dogs (Nyctereutes procyonoides viverrinus Temminck) utilizing the plastic injection method. The findings obtained were discussed in comparison with the facial artery of carnivorae. The facial artery diverged anterolaterally from the external carotid artery independently at a position between the origins of the lingual and the posterior auricular arteries when the external carotid bent laterally in front of the tympanic bulla. This artery, immediately after giving off the styloglossal branch, passed forwards superomedial to the digastricus muscle and medial to the insertion of the pterygoideus medialis muscle up to the posterolateral end of the mylohyoideus muscle, where the submental artery was derived. The submental ran forwards, giving off the digastric, the mylohyoid, the sublingual and the cutaneous branches, down to the posterolateral end of the intermandibular symphysis, where it anastomosed with the opposite fellow. The facial artery bent inferolaterally and passed laterally giving off the pterygoid and the inferior masseteric branches, and then emerged out onto the face through the facial vascular notch located inferoanterior to the angular process, which was extremely well developed in this species. The main stream of the artery ran anterosuperiorly at about 40 degrees to the horizontal plane along the anterior margin of the masseter muscle, since the notch was located on a projected level posterior to the middle of the zygomatic arch, giving rise en route to the anterior masseteric, the mandibular marginal, the buccal and the cutaneous branches. The artery finally divided into the inferior and superior labial arteries at the inferior margin of the mandibular origin of the buccalis muscle in the angle of the mouth. The facial artery of the raccoon dog was thus similar in its origin to that in the dog, cat and lion, but notably different in the short course of its submandibular region, and the nearly horizontal passage of the main route in the face, without the mandibular glandular branch. Additionally an extremely well developed angular process, a submandibular lobe and fairly posterior position of the vascular notch were found.     

A sero-epidemiological survey on the occurrence of opisthorchiid liver flukes in red foxes (Vulpes vulpes) in Berlin,Germany

Serum samples collected from red foxes in the city of Berlin between 1996 and 1999 were analysed for the presence of antibodies against Opisthorchis felineus and Metorchis bilis using an indirect ELISA. Out of 1,000 specimens, 30.6% and 46.5% reacted positively with specific O. felineus and M. bilis antigens, respectively. Seroprevalence in adult foxes was always higher than in juveniles. While no significant differences were observed in adult foxes throughout the period, in juvenile specimens seroprevalence declined from 1996 to 1997, then stayed at a comparable level in 1998 and increased in 1999. A varying availability of fresh cyprinid fish in different years seems to be the reason for changes in seroprevalence. By grouping the samples from juvenile foxes by season, antibodies against both Metorchis and Opisthorchis antigens started to appear between April and June, increased between July and September()and reached a level comparable to adult foxes in the October to December quarter. The lowest seroprevalence was found in Pankow, which is the district with the lowest share of the surface water.     

Helminth parasites of wild foxes (Vulpes vulpes L.) in The Netherlands

To study the helminth fauna of wild foxes (Vulpes vulpes) in The Netherlands, material was collected from 139 foxes. The following parasites were found. Cestodes:Taenia spp. 53.3%,Hymenolepis spp. 1.5%; Trematodes:Alaria alata 10.9%,Cryptocotyle lingua 3.6%,Euparyphium melis 1.5%,Apophallus donicus 0.7%; Nematodes:Toxocara canis 73.7%,Uncinaria stenocephala 59.9%,Capillaria aerophila 46.8%,C. plica 23.5%,Molineus patens 5.1%,Crenosoma vulpis 4.5%,Strongyloides spp. 0.7%. The tapewormsMesocestoides spp. andEchinococcus spp. were not seen. No relationship was observed between worm burden and sex, time of year or place of origin.     

Dose-dependent egg excretion in foxes ( Vulpes vulpes) after a single infection with Toxocara canis eggs

Faecal egg counts were performed daily for a period of 4 months on six silver fox cubs inoculated individually with an egg dose of 30, 100, 300, 1,000, 3,000, or 20,000 Toxocara canis eggs. At the lowest and the highest dose levels, the cubs did not develop patent infections. In the remaining cubs, the initial appearance of eggs in the faeces occurred 35-38 days post-infection (DPI), the patency period varied between 8 and 72 days, and the maximal EPG ranged from 980 to 5,700 (39-85 DPI). The highest egg excretion rates were found in cubs inoculated with 300 and 1,000 eggs. This study demonstrates that T. canis egg excretion rate in fox cubs is not linearly correlated with the ingestion level.     

Effect of selection for behavior on pituitary-adrenal axis and proopiomelanocortin gene expression in silver foxes (Vulpes vulpes)

Silver foxes from a commercial population (farm bred or unselected for behavior control) and from populations selected for tame behavior and enhanced aggressiveness towards man have been investigated. Plasma cortisol and adrenocorticotropic hormone (ACTH) levels, pituitary ACTH levels, POMC gene expression in the anterior pituitary, and corticotropin-releasing factor (CRF) gene expression in the hypothalamus were assessed. The results indicate that the males from the tame-behavior group have lower plasma cortisol and ACTH levels and POMC gene expression in the anterior pituitary in response to capture and handling in comparison with unselected ones. Foxes from the aggressive behavior group also have lower POMC expression, although plasma cortisol and ACTH levels remain the same as in unselected ones. The three groups of animals show no significant changes in the ACTH level in the pituitary and CRF expression in the hypothalamus.     

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.