Urbanization does not affect red foxes' interest in anthropogenic food, but increases their initial cautiousness.

Human presence and activities have profoundly altered animals' habitats, exposing them to greater risks but also providing new opportunities and resources. The animals' capacity to effectively navigate and strike a balance between risks and benefits is crucial for their survival in the Anthropocene era. Red foxes (Vulpes vulpes), adept urban dwellers, exhibit behavioral plasticity in human-altered environments. We investigated variations in detection frequency on trail cameras and the behavioral responses (explorative, bold, and fearful) of wild red foxes living along an urbanization gradient when exposed to a metal bin initially presented clean and then filled with anthropogenic food. All fox populations displayed an increased interest and similar explorative behavioral responses toward the anthropogenic food source, irrespective of the urbanization gradient. Despite no impact on explorative behaviors, foxes in more urbanized areas initially showed heightened fear toward the empty bin, indicating increased apprehension toward novel objects. However, this fear diminished over time, and in the presence of food, urban foxes displayed slightly reduced fear compared with their less urban counterparts. Our results highlight foxes' potential for adaptability to human landscapes, additionally underscoring the nuanced interplay of fear and explorative behavioral response of populations living along the urbanization gradient.

Wild red foxes (Vulpes vulpes) do not participate in SARS-CoV-2 circulation in Poland.

BACKGROUND: Biomonitoring is an essential activity for identifying possible vectors and reservoirs of pathogens and predicting potential outbreaks. Wild red foxes are present in both sylvatic and synanthropic environments, making them potential carriers of zoonotic pathogens. Experimental studies have shown that both coyotes and red foxes can transmit SARS-CoV-2. This study aimed to assess the prevalence and seroprevalence of SARS-CoV-2 in wild red foxes hunted in northern Poland. METHODS: Oral swabs, blood clots or heat tissue samples were collected from 292 red foxes hunted in northern Poland. We used both molecular (RT-PCR) and serological (IFA) approaches to detect SARS-CoV-2 infections in the sampled animals. RESULTS: We did not find any evidence of SARS-CoV-2 infection in the collected samples, using both molecular and serological methods. CONCLUSIONS: Despite foxes having frequent contact with humans, human waste, and other animals, they do not appear to participate in the circulation of the SARS-CoV-2 virus in our geographical region. Nevertheless, we believe that continuous biomonitoring should be performed to assess the SARS-CoV-2 epidemiological situation in the wild.

WILDbase: towards a common database to improve wildlife disease surveillance in Europe.

BackgroundTo be better prepared for emerging wildlife-borne zoonoses, we need to strengthen wildlife disease surveillance.AimThe aim of this study was to create a topical overview of zoonotic pathogens in wildlife species to identify knowledge gaps and opportunities for improvement of wildlife disease surveillance.MethodsWe created a database, which is based on a systematic literature review in Embase focused on zoonotic pathogens in 10 common urban wildlife mammals in Europe, namely brown rats, house mice, wood mice, common voles, red squirrels, European rabbits, European hedgehogs, European moles, stone martens and red foxes. In total, we retrieved 6,305 unique articles of which 882 were included.ResultsIn total, 186 zoonotic pathogen species were described, including 90 bacteria, 42 helminths, 19 protozoa, 22 viruses and 15 fungi. Most of these pathogens were only studied in one single animal species. Even considering that some pathogens are relatively species-specific, many European countries have no (accessible) data on zoonotic pathogens in these relevant animal species. We used the Netherlands as an example to show how this database can be used by other countries to identify wildlife disease surveillance gaps on a national level. Only 4% of all potential host-pathogen combinations have been studied in the Netherlands.ConclusionsThis database comprises a comprehensive overview that can guide future research on wildlife-borne zoonotic diseases both on a European and national scale. Sharing and expanding this database provides a solid starting point for future European-wide collaborations to improve wildlife disease surveillance.

Echinococcus multilocularis and Other Intestinal Parasites of the Red Fox (Vulpes vulpes) from the Pomerania Region, Northern Poland.

The aim of the study was to determine the species composition of the intestinal parasite fauna of foxes from the Pomerania region, with a particular emphasis on helminth species considered dangerous to humans, and to determine their prevalence and intensity of infection. In total, 165 digestive systems from foxes inhabiting the Pomeranian region were examined. The prevalence of intestinal parasites among the studied foxes was 61.8%. Our findings confirm that foxes in Pomerania carry various parasites, some of which pose a direct threat to human health. As such, constant monitoring of their infestation is essential. Particular attention should be paid to parasite species with potential for transmission to humans, such as Echinococcus multilocularis, Alaria alata and Toxocara canis, whose respective prevalence was found to be 10.9%, 17.6% and 28.5%.

Maintenance of a narrow hybrid zone between native and introduced red foxes (Vulpes vulpes) despite conspecificity and high dispersal capabilities.

Human-facilitated introductions of nonnative populations can lead to secondary contact between allopatric lineages, resulting in lineage homogenisation or the formation of stable hybrid zones maintained by reproductive barriers. We investigated patterns of gene flow between the native Sacramento Valley red fox (Vulpes vulpes patwin) and introduced conspecifics of captive-bred origin in California's Central Valley. Considering their recent divergence (20-70 kya), we hypothesised that any observed barriers to gene flow were primarily driven by pre-zygotic (e.g. behavioural differences) rather than post-zygotic (e.g. reduced hybrid fitness) barriers. We also explored whether nonnative genes could confer higher fitness in the human-dominated landscape resulting in selective introgression into the native population. Genetic analysis of red foxes (n = 682) at both mitochondrial (cytochrome b + D-loop) and nuclear (19,051 SNPs) loci revealed narrower cline widths than expected under a simulated model of unrestricted gene flow, consistent with the existence of reproductive barriers. We identified several loci with reduced introgression that were previously linked to behavioural divergence in captive-bred and domestic canids, supporting pre-zygotic, yet possibly hereditary, barriers as a mechanism driving the narrowness and stability of the hybrid zone. Several loci with elevated gene flow from the nonnative into the native population were linked to genes associated with domestication and adaptation to human-dominated landscapes. This study contributes to our understanding of hybridisation dynamics in vertebrates, particularly in the context of species introductions and landscape changes, underscoring the importance of considering how multiple mechanisms may be maintaining lineages at the species and subspecies level.

Epidemiology of sarcoptic mange in a geographically constrained insular red fox population.

BACKGROUND: Sarcoptic mange is a skin disease caused by the contagious ectoparasite Sarcoptes scabiei, capable of suppressing and extirpating wild canid populations. Starting in 2015, we observed a multi-year epizootic of sarcoptic mange affecting a red fox (Vulpes vulpes) population on Fire Island, NY, USA. We explored the ecological factors that contributed to the spread of sarcoptic mange and characterized the epizootic in a landscape where red foxes are geographically constrained. METHODS: We tested for the presence of S. scabiei DNA in skin samples collected from deceased red foxes with lesions visibly consistent with sarcoptic mange disease. We deployed 96-100 remote trail camera stations each year to capture red fox occurrences and used generalized linear mixed-effects models to assess the affects of red fox ecology, human and other wildlife activity, and island geography on the frequency of detecting diseased red foxes. We rated the extent of visual lesions in diseased individuals and mapped the severity and variability of the sarcoptic mange disease. RESULTS: Skin samples that we analyzed demonstrated 99.8% similarity to S. scabiei sequences in GenBank. Our top-ranked model (weight = 0.94) showed that diseased red foxes were detected more frequently close to roadways, close to territories of other diseased red foxes, away from human shelters, and in areas with more mammal activity. There was no evidence that detection rates in humans and their dogs or distance to the nearest red fox den explained the detection rates of diseased red foxes. Although detected infrequently, we observed the most severe signs of sarcoptic mange at the periphery of residential villages. The spread of visual signs of the disease was approximately 7.3 ha/week in 2015 and 12.1 ha/week in 2017. CONCLUSIONS: We quantified two separate outbreaks of sarcoptic mange disease that occurred > 40 km apart and were separated by a year. Sarcoptic mange revealed an unfettered spread across the red fox population. The transmission of S. scabiei mites in this system was likely driven by red fox behaviors and contact between individuals, in line with previous studies. Sarcoptic mange is likely an important contributor to red fox population dynamics within barrier island systems.

The Animal Welfare Consequences and Moral Implications of Lethal and Non-Lethal Fox Control Methods.

Control methods are applied worldwide to reduce predation on livestock by European red foxes (Vulpes vulpes). Lethal methods can inflict suffering; however, moral debate about their use is lacking. Non-lethal methods can also inflict suffering and can unintentionally lead to death, and yet both the welfare consequences and ethical perspectives regarding their use are rarely discussed. The aim of this study was to investigate the animal welfare consequences, the level of humaneness, the ethical considerations and the moral implications of the global use of fox control methods according to Tom Regan's animal rights view and Peter Singer's utilitarian view. According to Regan, foxes ought not to be controlled by either lethal or potentially harmful non-lethal methods because this violates the right of foxes not to be harmed or killed. According to Singer, if an action maximises happiness or the satisfaction of preferences over unhappiness or suffering, then the action is justified. Therefore, if and only if the use of fox control methods can prevent suffering and death in livestock in a manner that outweighs comparable suffering and death in foxes is one morally obligated to use them. It is clear that lethal fox control methods and some non-lethal methods are inhumane.

How do invasive predators and their native prey respond to prescribed fire?

Fire shapes animal communities by altering resource availability and species interactions, including between predators and prey. In Australia, there is particular concern that two highly damaging invasive predators, the feral cat (Felis catus) and European red fox (Vulpes vulpes), increase their activity in recently burnt areas and exert greater predation pressure on the native prey due to their increased exposure. We tested how prescribed fire occurrence and extent, along with fire history, vegetation, topography, and distance to anthropogenic features (towns and farms), affected the activity (detection frequency) of cats, foxes, and the native mammal community in south-eastern Australia. We used camera traps to quantify mammal activity before and after a prescribed burn and statistically tested how the fire interacted with these habitat variables to affect mammal activity. We found little evidence that the prescribed fire influenced the activity of cats and foxes and no evidence of an effect on kangaroo or small mammal (<800 g) activity. Medium-sized mammals (800-2000 g) were negatively associated with prescribed fire extent, suggesting that prescribed fire has a negative impact on these species in the short term. The lack of a clear activity increase from cats and foxes is likely a positive outcome from a fire management perspective. However, we highlight that their response is likely dependent upon factors like fire size, severity, and prey availability. Future experiments should incorporate GPS-trackers to record fine-scale movements of cats and foxes in temperate ecosystems immediately before and after prescribed fire to best inform management within protected areas.

Host weight, seasonality and anthropogenic factors contribute to parasite community differences between urban and rural foxes.

Pathogens often occur at different prevalence along environmental gradients. This is of particular importance for gradients of anthropogenic impact such as rural-urban transitions presenting a changing interface between humans and wildlife. The assembly of parasite communities is affected by both the external environmental conditions and individual host characteristics. Hosts with low body weight (smaller individuals or animals with poor body condition) might be more susceptible to infection. Furthermore, parasites' mode of transmission might affect their occurrence: rural environments with better availability of intermediate hosts might favour trophic transmission, while urban environments, typically with dense definitive host populations, might favour direct transmission. We here study helminth communities (141 intestinal samples) within the red fox (Vulpes vulpes), a synanthropic host, using DNA metabarcoding of multiple marker genes. We analysed the effect of urbanisation, seasonality and host-intrinsic (weight, sex) variables on helminth communities. Helminth species richness increased in foxes with lower body weight and in winter and spring. Season and urbanisation, however, had strong effects on the community composition, i.e., on the identity of the detected species. Surprisingly, transmission in two-host life cycles (trophic transmission) was more pronounced in urban Berlin than in rural Brandenburg. This disagrees with the prevailing hypothesis that trophically transmitted helminths are less prevalent in urban areas than in rural areas. Generally, co-infestations with multiple helminths and high infection intensity are associated with lighter (younger, smaller or low body condition) animals. Both host-intrinsic traits and environmental drivers together shape parasite community composition and turnover along urban-rural gradients.

Effects of resource availability and interspecific interactions on Arctic and red foxes' winter use of ungulate carrion in the Fennoscandian low-Arctic tundra.

In the Arctic tundra, predators face recurrent periods of food scarcity and often turn to ungulate carcasses as an alternative food source. As important and localized resource patches, carrion promotes co-occurrence of different individuals, and its use by predators is likely to be affected by interspecific competition. We studied how interspecific competition and resource availability impact winter use of carrion by Arctic and red foxes in low Arctic Fennoscandia. We predicted that the presence of red foxes limits Arctic foxes' use of carrion, and that competition depends on the availability of other resources. We monitored Arctic and red fox presence at supp lied carrion using camera traps. From 2006 to 2021, between 16 and 20 cameras were active for 2 months in late winter (288 camera-winters). Using a multi-species dynamic occupancy model at a week-to-week scale, we evaluated the use of carrion by foxes while accounting for the presence of competitors, rodent availability, and supplemental feeding provided to Arctic foxes. Competition affected carrion use by increasing both species' probability to leave occupied carcasses between consecutive weeks. This increase was similar for the two species, suggesting symmetrical avoidance. Increased rodent abundance was associated with a higher probability of colonizing carrion sites for both species. For Arctic foxes, however, this increase was only observed at carcasses unoccupied by red foxes, showing greater avoidance when alternative preys are available. Supplementary feeding increased Arctic foxes' carrion use, regardless of red fox presence. Contrary to expectations, we did not find strong signs of asymmetric competition for carrion in winter, which suggests that interactions for resources at a short time scale are not necessarily aligned with interactions at the scale of the population. In addition, we found that competition for carcasses depends on the availability of other resources, suggesting that interactions between predators depend on the ecological context.

Forensic findings in urban red fox mortality in the metropolitan area of Madrid, 2014-2022.

The expanding presence of red foxes (Vulpes vulpes) in urban and suburban regions could potentially lead to increased instances of human aggression towards this species. We studied 10 deceased red foxes that were submitted by law enforcement agencies in the metropolitan area of Madrid in 2014-2022 because of suspected abuse. Forensic autopsies were performed to establish the cause and manner of death. In 4 of the 10 cases, the cause of death was deemed unnatural, involving blunt-force trauma (n = 2), asphyxia resulting from hanging (n = 1), and firearm injury (n = 1). Among the remaining cases, most had succumbed to natural causes (n = 4), often marked by severe emaciation and a high burden of parasites, primarily Sarcoptes scabiei. In 2 cases, death was undetermined given the poor preservation of the carcass. The growing prevalence of wildlife species in urban areas, particularly red foxes, may require forensic veterinary investigation of deaths potentially related to abuse.

Mitogenomic analysis of Rüppell's fox (Vulpes rueppellii) confirms phylogenetic placement within the Palaearctic clade shared with its sister species, the red fox (Vulpes vulpes).

The Rüppell's fox (Vulpes rueppellii) inhabits desert regions across North Africa, the Arabian Peninsula and southwestern Asia. Its phylogenetic relationship with other fox species, especially within the phylogeographic context of its sister species, V. vulpes, remain unclear. We here report the sequencing and de-novo assembly of the first annotated mitogenome of V. rueppellii, analysed with data from other foxes (tribe Vulpini, subfamily Caninae). We used four bioinformatic approaches to reconstruct the V. rueppellii mitogenome, obtaining identical sequences except for the incompletely assembled tandem-repeat region within the D-loop. The mitogenome displayed an identical organization, number and length of genes as V. vulpes. We found high support for clustering of both known subclades of V. rueppellii within the Palearctic clade of V. vulpes, rendering the latter species paraphyletic, consistent with previous analyses of shorter mtDNA fragments. More work is needed for a full understanding of the evolutionary drivers and consequences of hybridization in foxes.

Acanthocephala Species of Mammals in Türkiye and A New Species Record from Foxes.

Acanthocephaliasis is a zoonotic parasitic infection of vertebrates. The phylum Acanthocephala contains nearly 1500 acanthocephalan species. The Archiacanthocephala class is observed in terrestrial habitats and usually has a large, spineless trunk. Acanthocephalans are parasitic worms that use insects as intermediate hosts in their two-host life cycles. Insects, millipedes, and crustaceans in terrestrial areas serve as intermediate hosts and birds and mammals as definitive hosts. Acanthocephalans collected from the red fox (Vulpes vulpes) found dead on the road to Sarikamis-Kars in 1995 and stored in formaldehyde were kept in Ondokuz Mays University Faculty of Veterinary Medicine, Veterinary Parasitology Laboratory Museum until 2023 after our parasitological study found an infected red fox with Pachysentis sp. This study provides the anatomy of the acanthocephalans and the laboratory practice necessary for a good and reliable diagnosis. This study reports a new species, Pachysentis sp., of acanthocephalan (thorny-headed worm) found in red foxes for Türkiye. On the basis of relevant articles, we have created a key to Acanthocephala species occurring in mammals.

Study of Canine Distemper Virus Presence in Catalonia's Wild Carnivores through H Gene Amplification and Sequencing.

Canine distemper virus (CDV) is recognised worldwide as an important pathogen in both domestic and wild carnivores. Few data are available on its impact and spread on the wildlife/wildlife-domestic animal-environment interface. This study, aimed at developing a conservation-oriented control strategy, analysed 89 sick or deceased animals from 2019 to 2023 at the Wildlife Rehabilitation Centre in Torreferrussa. RT-PCR and sequencing of the partial H gene were used to detect and analyse CDV in tissues. The total positive percentage was 20.22% (18/89), comprising 13 red foxes (44.8%), 4 European badgers (28.6%), and 1 American mink (4.5%), while 24 Eurasian otters tested negative. Phylogenetic analysis indicated that all of the CDV strains belong to the European lineage. Geographically distant individuals and different species shared the same viral strain, suggesting a strong capacity of CDV for interspecies and long-distance transmission. This calls for further research, particularly focusing on potential impacts of CDV on endangered carnivores.

Tumor and Tumor-like Lesions in Red Foxes (Vulpes vulpes) from Croatia.

The red fox, found on all continents except Antarctica, occupies diverse habitats. In Croatia, it is an indigenous wild species with a population density of 0.7 animals per square kilometer. While tumors in wild animals from the Canidae family are scarce, the true prevalence and diversity of tumors are likely underestimated due to limited research. So far, a limited number of tumors have been observed among the red fox population, either in their natural habitat or in captivity. As part of the National Rabies Control Program, we examined 1890 red fox carcasses over a four-year period. Our focus was on identifying abnormalities on the skin and internal organs that suggest potential neoplastic proliferation. Five red foxes, three males and two females, were found to have growths resembling potential tumors. Their age distribution spanned from 2 to 7 years. Microscopic investigation revealed two collagenous hamartomas, two Meibomian gland adenomas, and one intra-abdominal teratoma within a cryptorchid testis. This retrospective study aims to provide a comprehensive description of tumor and tumor-like lesions observed in free-range red foxes from Croatia, marking the first research of its kind in Croatia.

Camera traps reveal a high prevalence of sarcoptic mange in red foxes from northern Spain.

The mite Sarcoptes scabiei affects numerous mammal species causing the sarcoptic mange, a widespread disease with relevance for wildlife conservation, welfare, and management. The red fox (Vulpes vulpes) could become infested by direct and indirect routes leading to external skin lesions potentially recognizable by devices such as camera traps (CTs). In the present study, 86 randomly placed CTs were used to investigate the apparent prevalence and severity of S. scabiei in a red fox population from northern Spain. Their potential environmental and population-related drivers were also assessed. A total of 341 independent encounters were examined to visually identify mange-compatible lesions. The apparent prevalence was 19.16% (confidence interval (CI) 95%: 15.08-23.80) of which 82.81% (CI95%: 71.33-91.10) were severe. Our results revealed that habitat attributes such as lower altitudes, higher coverage of water-linked habitats and woodland predominance, were significant predictors of the apparent risk of mange. The models also suggested that the apparent prevalence of mange was associated with poor body condition and elevated frequencies of spatial coincidence among fox encounters, which facilitates indirect transmission. Interestingly, we did not observe mange-compatible lesions in other sympatric wild species (>15,000 encounters examined). This could be explained by the mite's host specificity and the low probability that these other potential hosts use sites where transmission among foxes usually occurs, such as dens. This study illustrates how camera trapping can be used as an interesting tool for the surveillance of wildlife diseases, thus overcoming the logistic constraints derived from direct sampling and allowing the early detection and better management of pathogens in the riskiest areas.

The first record of Brachylaima ezohelicis (Trematoda: Brachylaimidae) in the red fox (Vulpes vulpes schrencki).

Brachylaima spp. are trematodes that have a unique life cycle as they exclusively use land snails as the intermediate host. Although their intermediate host has been well studied, very little information is available about their definitive host, partly as isolation of its adult stage from wild animals is rare. We found three trematodes in the small intestine of a red fox (Vulpes vulpes schrencki) in Hokkaido, the northernmost island of Japan. The trematodes were identified as Brachylaima ezohelicis based on morphological features and genetic analysis, which is believed to have a definitive avian host. The morphological features of the isolated trematodes were consistent with B. ezohelicis samples grown in the definitive host except for body length. Our study suggests that B. ezohelicis uses mammals as definitive hosts as well as birds.

Phylogenetic status and diet of red fox (Vulpes vulpes griffithii) inhabiting Ayubia National Park, Pakistan

Abstract The red fox (Vulpes vulpes) is a medium-sized carnivore that occurs in different regions of Pakistan, however, still lacks scientific data on its ecology and distribution. The current study investigated the phylogenetic status and diet of the red fox (V.v. griffithii) occurring in Ayubia National Park, Pakistan. Through camera trapping and molecular analysis, we confirmed the occurrence of red fox in the study area. Based on mitochondrial cytochrome B (304 bp) and limited sampling, nearly all red foxes of Ayubia National Park and surrounding Himalayan ranges fall within Holarctic maternal lineage, whereas red foxes found in plains of Pakistan are part of the basal Palearctic maternal lineage. Using 32 scats, we found that red fox diet comprises of 80% animal-based prey species (both wild and domestic) and 19% plant matter. The wild animal prey species included Cape hare (Lepus capensis) and flying squirrel (Pteromyini sp.), which constituted 17% and 15% of diet, respectively. Red foxes infrequently consumed House mouse (Mus musculus), Himalayan Palm civet (Paguma larvata) and sheep (Ovis aries), each comprising around 6% to 9% of red fox diet. The fox species also scavenged on domestic donkey opportunistically. Based on our sampling, our study suggests that the red fox (V.v. griffithii) that occurs in Ayubia National Park and across the lesser Himalayan ranges belongs to Holarctic maternal lineage. The study also highlights consumption of plant seeds by red foxes, indicating it may play an important ecological role in seed dispersal in Ayubia National Park.

Resumo A raposa-vermelha (Vulpes vulpes) é um carnívoro de médio porte que ocorre em diferentes regiões do Paquistão, porém ainda carece de dados científicos sobre sua ecologia e distribuição. O presente estudo investigou o status filogenético e a dieta da raposa-vermelha (V.v. griffithii) que ocorre no Parque Nacional de Ayubia, Paquistão. Por meio de armadilhas fotográficas e análises moleculares, confirmamos a ocorrência de raposa-vermelha na área de estudo. Com base no citocromo B mitocondrial (304 bp) e amostragem limitada, quase todas as raposas-vermelhas do Parque Nacional de Ayubia e áreas circundantes do Himalaia se enquadram na linhagem materna holártica, enquanto as raposas-vermelhas encontradas nas planícies do Paquistão fazem parte da linhagem materna basal paleártica. Usando 32 fezes, descobrimos que a dieta da raposa-vermelha compreende 80% de espécies de presas de origem animal (selvagens e domésticas) e 19% de matéria vegetal. As espécies de presas de animais selvagens incluíram a lebre-do-cabo (Lepus capensis) e o esquilo-voador (Pteromyini sp.), que constituíram 17% e 15% da dieta, respectivamente. As raposas-vermelhas consumiam raramente ratos domésticos (Mus musculus), algas do Himalaia (Paguma larvata) e ovelhas (Ovis aries), cada um compreendendo cerca de 6% a 9% da dieta da raposa-vermelha. A espécie de raposa também se alimentava de burros domésticos de forma oportunista. Com base em nossa amostragem, nosso estudo sugere que a raposa-vermelha (V.v. griffithii) que ocorre no Parque Nacional de Ayubia e nas cordilheiras menores do Himalaia pertence à linhagem materna holártica. O estudo também destaca o consumo de sementes de plantas por raposas-vermelhas, indicando que pode desempenhar um papel ecológico importante na dispersão de sementes no Parque Nacional de Ayubia.

Characterization of Inflammasomes and Their Regulation in the Red Fox.

BACKGROUND: Inflammasomes recognize endogenous and exogenous danger signals, and subsequently induce the secretion of IL-1ß. Studying inflammasomes in the red fox (Vulpes vulpes) is crucial for wildlife veterinary medicine, as it can help control inflammatory diseases in foxes. METHODS: We investigated the activation and intracellular mechanisms of three inflammasomes (NLRP3, AIM2, and NLRC4) in fox peripheral blood mononuclear cells (PBMCs), using established triggers and inhibitors derived from humans and mice. RESULTS: Fox PBMCs exhibited normal activation and induction of IL-1ß secretion in response to representative inflammasome triggers (ATP and nigericin for NLRP3, dsDNA for AIM2, flagellin for NLRC4). Additionally, PBMCs showed normal IL-1ß secretion when inoculated with inflammasome-activating bacteria. In inhibitors of the inflammasome signaling pathway, fox inflammasome activation was compared with mouse inflammasomes. MCC950, a selective NLRP3 inhibitor, suppressed the secretion of dsDNA- and flagellin-mediated IL-1ß in foxes, unlike mice. CONCLUSIONS: These findings suggest that NLRP3 may have a common role in dsDNA- and flagellin-mediated inflammasome activation in the red fox. It implies that this fox inflammasome biology can be applied to the treatment of inflammasome-mediated diseases in the red fox.

Dental and temporomandibular joint pathology of the red fox (Vulpes vulpes).

Skulls from 305 red foxes (Vulpes vulpes) were examined using predefined criteria to assess for the presence and severity of dental and temporomandibular joint (TMJ) pathology. Of the 305 specimens examined, 131 were male (42.9%), 103 were female (33.4%), 71 were of unknown sex (23.3%), 238 were adults (78.03%) and 67 were young adults (21.97%), with juveniles excluded from the study. Of a maximum of 12,810 possible teeth, 12,355 (96.5%) were present for examination, 72 (0.6%) were absent congenitally, 97 (0.8%) were acquired tooth loss and 280 (2.2%) were absent artefactually. Eight teeth (0.06%) in five specimens (1.6%) had abnormal tooth form and four (0.03%) supernumerary teeth were present across four (1.3%) specimens. Ten persistent deciduous teeth were present in seven (2.3%) specimens and six (0.05%) unerupted teeth were found in four (1.1%) specimens. Root number variation was present in 51 (0.4%) teeth, predominantly premolar teeth. Twenty-one (6.9%) specimens had lesions consistent with enamel hypoplasia and 42 (13.8%) showed root fenestrations in the maxillary alveolar bone. Periodontitis and attrition/abrasion were present in most specimens (56.7% and 96.1%, respectively). Three-hundred and eighty (3.1%) teeth were fractured, with the most common fracture type being root fractures. Eleven periapical lesions were found in nine (0.03%) specimens. Six-hundred and eight TMJs were evaluated and many specimens (11.5%) had evidence of low-grade TMJ osteoarthritis. Overall, these red foxes share similar dental pathology to other foxes, but had a higher prevalence of congenital tooth absence, persistent deciduous teeth, TMJ pathology and enamel hypoplasia.