Search Results (40)

To date, five herpesviruses have been identified in Leporidae (LeHV-1, LeHV-2, LeHV-3, LeHV-4, and LeHV-5). Two of these have been shown to infect the European rabbit (Oryctolagus cuniculus), causing either asymptomatic infection (LeHV-2, a gammaherpesvirus) or virulent disease (LeHV-4, an alphaherpesvirus). Unfortunately, apart from LeHV-4, for which complete genome sequences are available, molecular data on leporid herpesviruses are extremely limited, with no sequences available in public databases for LeHV-1 and LeHV-3, and only a few short sequences for LeHV-2 and LeHV-5. In this study, we investigated the presence of herpesviruses in biological samples from wild rabbits (n = 34) found dead in the field during 2024. A pan-herpesvirus nested PCR directed to the herpesviral DNA polymerase gene was used for screening. Positive samples (n = 14, 41.17%) were further investigated by sequencing analysis of a longer region of the DNA polymerase gene, as well as the glycoprotein B gene and the terminase gene. Blastn analysis of the amplicons revealed the highest similarity to gammaherpesvirus. Phylogenetic analyses based on glycoprotein B, DNA polymerase, and concatenated amino acid sequences consistently placed the newly identified LeHV-6 in close proximity to LeHV-5. Both viruses form a well-supported clade within the Gammaherpesvirinae, clustering with rodent-associated herpesviruses, such as Murine herpesvirus, MuHV-4, and A. sylvaticus rhadinovirus 1. Considering the species susceptibility and the nucleotide similarities with the five previously described leporid herpesviruses, we conclude that a new rabbit gammaherpesvirus has been identified, which we propose to name LeHV-6. Full article

(1) Background: We combined physiological and morphological data of the European rabbit (Oryctolagus cuniculus) to provide insights into the question of how urbanization affects the health of urban wildlife populations. (2) Methods: We dissected 39 urban and 34 rural wild rabbits in order to compare organ weights, as well as stomach contents. Furthermore, we collected blood and fecal samples. (3) Results: Rural rabbits had a significantly longer body and a higher body weight as well as more fat tissue around their kidneys compared to urban rabbits. In contrast, the stomach, the intestines, the liver, the lung, and the brain of urban rabbits were significantly heavier. The amount of hematocrit, hemoglobin, and the mean corpuscular volume was significantly higher in urban rabbits. The caloric energy content of the stomach was comparable between rural and urban rabbits and was merely influenced by the season being higher in autumn. Rural rabbits had an overall higher mean parasite index compared to urban rabbits. (4) Conclusions: The results of our study allow for a deeper understanding of how density-dependent (e.g., transmission of diseases) and density-independent factors (e.g., food quality) influence the health status and life history traits of urban wildlife populations compared to their rural counterparts. Full article

In a 1975 review, red kangaroos in the arid rangelands of Australia were said to be favoured with an anomalous prosperity following the introduction of ruminant livestock. In the western and central locations reviewed, this was not sustained, but in the sheep rangelands of Southern Australia, it is often claimed that such prosperity continues. Here, as elsewhere, the marsupial herbivore guild (kangaroos, wallabies, bettongs and bandicoots) has been simplified by the extinction of the smaller species (the anomaly), while large kangaroos remain abundant. However, the mammalian herbivore guild has gained complexity with not only the introduction of managed ruminant livestock, some of which run wild, but also game like rabbits. We studied the population dynamics, habitat selection and individual mobility of red, western and eastern grey kangaroos, common wallaroos, Merino sheep, feral goats and European rabbits at Fowlers Gap Station in far northwestern New South Wales, Australia. This site is representative of the arid chenopod (Family: Chenopodiaceae) shrublands stocked with sheep, where sheep and red kangaroos dominate the mammalian herbivores by biomass. The study site comprised two contiguous pairs of stocked and unstocked paddocks: a sloping run-off zone and a flat run-on zone, covering a total area of 2158 ha. This three-year study included initial rain-deficient (drought) months followed by more regular rainfall. Red kangaroos showed avoidance of sheep when given the opportunity and heightened mobility in response to localized drought-breaking storms and dispersion of the sheep flock at lambing. Western grey kangaroos were sedentary and did not dissociate from sheep. These effects were demonstrated at the population level and the individual level through radio-tracking a small cohort of females. The other kangaroo species and goats were transient and preferred other habitats. Rabbits were persistent and localized without strong interactions with other species. The results are discussed with a focus on the red kangaroo and some causes for its resilience in the sheep rangelands. Full article

Background: European wild rabbits (Oryctolagus cuniculus) are closely connected to the natural environment and might be a potential source of pathogenic bacteria and/or antimicrobial-resistant bacteria. The objective was to identify the bacterial community (species and genera) that colonizes the nasal cavities of European wild rabbits as well as to study the antimicrobial resistance (AMR) phenotypes of bacteria of public health interest. Methods: A total of 147 nasal swabs individually collected from wild rabbits in Spain and Portugal (between 2022 and 2024) were studied. Samples were inoculated in different culture media, and isolates were identified by MALDI-TOF. The AMR phenotypes of staphylococci, mammaliicocci, enterococci and Enterobacterales were evaluated by the disk-diffusion method. Results: Overall, 557 non-repetitive isolates were obtained (1 isolate per species and AMR phenotype of each animal). A wide diversity of genera (n = 40) and species (n = 90) was found. Staphylococcus (21.2%), Mammaliicoccus (11.7%), Enterococcus (23.3%), Enterobacter (9.2%), Citrobacter (4.5%) and Escherichia (5.9%) were the most detected genera. Most animals presented more than one genera (78.9%), and in 15.7% of them, at least five genera were identified. Susceptibility to all antimicrobials tested was found in 37.2%, 38.5% and 51.6% of staphylococci/mammaliicocci, enterococci and Escherichia coli isolates; moreover, multidrug resistance was detected in 10.4%, 14.6% and 9.6% of these groups of bacteria. Moreover, important species of pathogenic bacteria were found, such as Yersinia enterolocolitica (0.5%) and Bordetella bronchiseptica (0.2%), among others. Conclusions: A high bacterial diversity was detected in the nasal cavities of European wild rabbits from the Iberian Peninsula, including pathogenic species and/or resistant strains of public health interest. Full article

The European rabbit exists in the wild and has several highly bred domesticated forms. There are well-separated wild European rabbit populations, and intensive breeding has resulted in various forms and utilizations. In this work, we aimed to carry out an extended WGS-based population genomics study on several wild European rabbit populations and selected breeds. Utilizing multiple methods, we showed that although domestic and wild populations were clearly separated, there was evidence of admixture between them in France and Hungary. The populations showed various levels of inbreeding, with one of the Hungarian subpopulations having excess runs of homozygosity. We identified numerous variants fixed in either domestic or wild animals, two of which were found to be fixed at different alleles in the two populations. Some putatively selected regions did not overlap with any known genes in the rabbit genome, suggesting some importance to these intergenic sites. The enrichment of selected regions in certain types of transcription factor binding sites suggests a possible role for these regulatory elements during domestication. In addition, the new high-coverage rabbit whole-genome sequences may provide helpful material for further population genetics analyses. Full article

This study examined the grazing pressure and interactions between four species of wild kangaroos (Red Kangaroo Osphranter rufus, Common Wallaroo O. robustus, Eastern Grey Kangaroo Macropus giganteus, Western Grey Kangaroo M. fuliginosus), free-ranging feral goats (Capra hircus) and European rabbits (Oryctolagus cuniculus), and stocked Merino sheep (Ovis aries). The study site comprised two contiguous pairs of stocked and unstocked paddocks, one a sloping run-off zone, the other a flat run-on zone, covering a total area of 2158 ha. These paddocks on Fowlers Gap Station in far north-western New South Wales, Australia, are representative of the arid chenopod (Family: Chenopodiaceae) shrublands stocked with sheep. Sheep and red kangaroos dominate the mammalian herbivores by biomass. The study examined the relative grazing pressure exerted by the seven species of mammalian herbivores in stocked and unstocked conditions, where only sheep were confined, across a three-year period that included rain-deficient (drought) months. The effects of climate (especially rainfall and temperature) and herbivore density on the standing biomass of pasture were teased out at a macro-scale. Herbivory at a micro-scale was examined using open and exclosed plots with detection of herbivore species by fecal deposition and time-lapse videography. Sheep exerted the highest grazing pressure and there was no compensatory increase in grazing pressure by other herbivores in unstocked paddocks. Rainfall was a key driver of pasture biomass and condition and loss by senescence typically outweighed grazing pressure. Grazing effects at a micro-scale were plot-specific and complex. The results are discussed in relation to the sustainable management of rangelands for production and wildlife. Full article

Francisella tularensis is a vector-borne zoonotic bacterium that causes tularemia, a disease of great importance for animal and public health. Although wild lagomorphs are considered one of the major reservoirs of this bacterium, information about the circulation of F. tularensis in European wild rabbit (Oryctolagus cuniculus) and Iberian hare (Lepus granatensis) populations in Europe is still very limited. In Spain, F. tularensis is present in northern central regions, with recurrent outbreaks occurring annually. However, southern Spain has been neglected in terms of monitoring and research. Thus, the aim of this study was to investigate the occurrence of F. tularensis in wild lagomorphs in the Mediterranean ecosystems of southern Spain through using molecular techniques. Spleen samples from 774 European wild rabbits and 178 Iberian hares were collected on 135 hunting grounds between the 2017/2018 and 2022/2023 hunting seasons. A primer set targeting the 16S rRNA gene was used for the detection of F. tularensis DNA. None of the 952 (0.0%; 95%CI: 0.0–0.4) wild lagomorphs sampled showed presence of F. tularensis DNA. Our finding indicates the absence or very low circulation of the bacterium in wild rabbit and Iberian hare populations in the Mediterranean ecosystems of southern Spain, denoting a limited risk of transmission of this pathogen from wild lagomorphs to other sympatric species, including human beings, in this Iberian region. Full article

Encephalitozoon cuniculi and Encephalitozoon hellem are fungus-related, obligate intracellular pathogens belonging to the microsporidia. Both microorganisms occur in mammals, birds and even humans, thus revealing a zoonotic potential. Knowledge of their relevance in wild rabbits is very limited so far. Thus, the aim of the present study was to investigate the occurrence of E. cuniculi and E. hellem in wild rabbit populations in southern Germany (Bavaria). Therefore, blood and organ samples (brain/kidney) of 158 wild rabbits were investigated by immunofluorescence and PCR-based assays. Antibodies to E. cuniculi were detected in 24 of the 158 (15.2%) wild rabbits, while DNA of E. cuniculi was found in 7 (4.4%) and DNA of E. hellem was found in 3 (1.9%). Sequencing identified E. cuniculi genotype 1. This study provides the first E. cuniculi genotype determination in free-living wild rabbits worldwide and the first evidence of E. hellem in rabbits worldwide. Wild rabbits should, therefore, be regarded as a reservoir for both pathogens and, on the basis of molecular evidence from kidney tissue and presumed urine excretion, also as a source of infection for E. cuniculi for animals and humans. Full article

Rabbit haemorrhagic disease viruses (RHDV) belong to the family Caliciviridae, genus Lagovirus europaeus, genogroup GI, comprising four genotypes GI.1–GI.4, of which the genotypes GI.1 and GI.2 are pathogenic RHD viruses, while the genotypes GI.3 and GI.4 are non-pathogenic RCV (Rabbit calicivirus) viruses. Among the pathogenic genotypes GI.1 and GI.2 of RHD viruses, an antigenic variant of RHDV, named RHDVa—now GI.1a–RHDVa, was distinguished in 1996; and in 2010, a variant of RHDV—named RHDVb, later RHDV2 and now GI.2–RHDV2/b—was described; and recombinants of these viruses were registered. Pathogenic viruses of the genotype GI.1 were the cause of a disease described in 1984 in China in domestic (Oryctolagus (O.) cuniculus domesticus) and wild (O. cuniculus) rabbits, characterised by a very rapid course and a mortality rate of 90–100%, which spread in countries all over the world and which has been defined since 1989 as rabbit haemorrhagic disease. It is now accepted that GI.1–RHDV, including GI.1a–RHDVa, cause the predetermined primary haemorrhagic disease in domestic and wild rabbits, while GI.2–RHDV2/b cause it not only in rabbits, including domestic rabbits’ young up to 4 weeks and rabbits immunised with rabbit haemorrhagic disease vaccine, but also in five various species of wild rabbits and seven different species of hares, as well as wild ruminants: mountain muskoxen and European badger. Among these viruses, haemagglutination-positive, doubtful and harmful viruses have been recorded and described and have been shown to form phylogenogroups, immunotypes, haematotypes and pathotypes, which, together with traits that alter and expand their infectious spectrum (rabbit, hare, wild ruminant, badger and various rabbit and hare species), are the determinants of their pathogenicity (infectivity) and immunogenicity and thus shape their virulence. These relationships are the aim of our consideration in this article. Full article

Myxoma virus (MYXV) is a Leporipoxvirus (genus) belonging to the family Poxviridae; it is characterised by a genome of approximately 161 kb dsDNA encoding for several proteins that play an essential role in both host spectrum determination and immunomodulation. The healthy reservoir of the virus is Sylvilagus spp. At the same time, in wild and domestic European rabbits (Oryctolagus cuniculus), MYXV is the etiologic agent of myxomatosis, a disease with an extremely high mortality rate. In 2014, an interspecies jump of MYXV was reported in Lepus europaeus in the UK. In 2018, myxomatosis induced by a new recombinant strain called MYXV-To was identified during a large outbreak in Iberian hares (Lepus granatensis) in Spain. Here, we describe the case of myxomatosis in another hare species: an adult male Italian hare (Lepus corsicanus) found dead in 2018 in Sicily with lesions suggestive of myxomatosis and treponema infection. Laboratory tests, e.g., end-point PCR and negative staining electron microscopy, confirmed the presence of both pathogens. MYXV was then isolated from tissue samples in permissive cells and sequenced using NGS technology. Main genomic differences concerning known MYXV strains are discussed. Full article

Coxiella burnetii is an important zoonotic pathogen of worldwide distribution that can infect a wide range of wild and domestic species. The European wild rabbit (Oryctolagus cuniculus) can play a role as a reservoir for this bacterium in certain epidemiological scenarios, but, to date, a very limited numbers of large-scale serosurveys have been conducted for this species worldwide. Although exposure in hare species has also been described, C. burnetii in Iberian hare (Lepus granatensis) has never been assessed. Here, we aimed to determine the seroprevalence and risk factors associated with C. burnetii exposure in wild lagomorphs in the Mediterranean ecosystems of southern Spain. Between the 2018/2019 and 2021/2022 hunting seasons, blood samples from 638 wild lagomorphs, including 471 wild rabbits and 167 Iberian hares, were collected from 112 hunting grounds distributed across all eight provinces of Andalusia (southern Spain). The overall apparent individual seroprevalence was 8.9% (57/638; 95% CI: 6.8–11.4). Antibodies against C. burnetii were found in 11.3% (53/471; 95% CI: 8.4–14.1) of the wild rabbits and 2.4% (4/167; 95% CI: 0.1–4.7) of the Iberian hares. Seropositive animals were detected for 16 (14.3%; 95% CI: 7.8–20.8) of the 112 hunting grounds tested and in all the hunting seasons sampled. A generalized estimating equations model showed that the geographical area (western Andalusia) and presence of sheep were risk factors potentially associated with C. burnetii exposure in wild lagomorphs. A statistically significant spatial cluster (p < 0.001) was identified in the south-west of Andalusia. Our results provide evidence of moderate, endemic and heterogeneous circulation of C. burnetii in wild lagomorph populations in Spanish Mediterranean ecosystems. Risk-based strategies for integrative surveillance programs should be implemented in these species to reduce the risk of transmission of the bacterium to sympatric species, including humans. Full article

The human footprint on marine and terrestrial ecosystems of the planet has been substantial, largely due to the increase in the human population with associated activities and resource utilization. Oceanic islands have been particularly susceptible to such pressures, resulting in high levels of loss of biodiversity and reductions in the numbers and sizes of wild populations. One archipelago that has suffered from human impact has been the Juan Fernández (Robinson Crusoe) Archipelago, a Chilean national park located 667 km west of Valparaíso at 33° S. latitude. The park consists of three principal islands: Robinson Crusoe Island (48 km²); Santa Clara Island (2.2 km²); and Alejandro Selkirk Island (50 km²). The latter island lies 181 kms further west into the Pacific Ocean. No indigenous peoples ever visited or lived on any of these islands; they were first discovered by the Spanish navigator, Juan Fernández, in 1574. From that point onward, a series of European visitors arrived, especially to Robinson Crusoe Island. They began to cut the forests, and such activity increased with the establishment of a permanent colony in 1750 that has persisted to the present day. Pressures on the native and endemic flora increased due to the introduction of animals, such as goats, rats, dogs, cats, pigs, and rabbits. Numerous invasive plants also arrived, some deliberately introduced and others arriving inadvertently. At present, more than three-quarters of the endemic and native vascular species of the flora are either threatened or endangered. The loss of vegetation has also resulted in a loss of genetic variability in some species as populations are reduced in size or go extinct. It is critical that the remaining genetic diversity be conserved, and genomic markers would provide guidelines for the conservation of the diversity of the endemic flora. To preserve the unique flora of these islands, further conservation measures are needed, especially in education and phytosanitary monitoring. Full article

One of the problematic points of rabbit breeding is that the nutritional requirements of the kits are not fully satisfied by the does’ milk production from the third week of lactation onwards. The prolactin receptor gene has a significant effect on reproductive processes, and its polymorphisms have been associated with milk production in several species (cattle, goats, sheep, and buffalo). The European wild rabbit (Oryctolagus cuniculus), has a more diverse genetic background compared to domesticated lines. In the course of our study, sequencing of the 1210 bp long segment of the PRLR gene promoter region was accomplished. We detected four point mutations (SNP1-407G > A, SNP2-496G > C, SNP3-926T> and SNP4-973A > C) and one microsatellite at position 574. In our population, the four SNPs were segregated into four genotypes: AACCCCCC, GGGGTTAA, AAGGTTAC, and GGGGTCAC. Our results show that the genotype in the homozygous form is associated with higher milk production (1564.7 ± 444.7 g) compared to the other three genotypes (AACCCCCC 1399.1 ± 326.8 g; GTGACCTT 1403.8 ± 517.1 g; GGGGTCAC 1220.0 ± 666.2 g), and the short microsatellite repeat (167 bp) also coincides with significantly higher milk production (1623.8 ± 525.1 g). These results make the marker-assisted selection possible also for domesticated lines. Full article

The zoonotic hepatitis E virus genotype 3 (HEV-3) causes most autochthonous human hepatitis E cases in Europe, which are due to the consumption of raw or undercooked food products of animal origin. Pigs and wild boars are considered the main reservoirs of this genotype, while rabbits are the reservoir of a distinct phylogenetic group named HEV-3ra, which is classified within the HEV-3 genotype but in a separate clade. Evidence for the zoonotic potential of HEV-3ra was suggested by its detection in immunocompromised patients in several European countries. HEV-3ra infection was found in farmed and feral rabbit populations worldwide and its circulation was reported in a few European countries, including Italy. Furthermore, Italy is one of the major rabbit meat producers and consumers across Europe, but only a few studies investigated the presence of HEV in this reservoir. The aim of this study was to assess the presence of HEV in 328 Italian hares and 59 farmed rabbits collected in 3 Italian macro-areas (North, North-Central, and South-Central), between 2019 and 2021. For this purpose, liver samples were used to detect HEV RNA using broad-range real-time RT-PCR and nested RT-PCR. Using 28 liver transudates from hares, the ELISA test for anti-HEV IgG detection was also performed. Neither HEV RNA nor anti-HEV antibodies were detected. Further studies will be conducted to assess the HEV presence in Italian lagomorphs to establish the role of this host and the possible risk of transmission for workers with occupational exposure, to pet owners and via food. Full article

In intense breeding programs, rabbits are exposed to numerous stress factors which could affect their welfare and health. It has been suggested that group housing is more comfortable for does and similar to the living conditions of European wild rabbits. In this study, we compared three different housing systems—single housing; housing in pairs; and housing in groups of three does—to test whether there is a measurable impact on skin lesions, health, and hair corticosterone concentration (HCC) of their kits. The number of kits with lesions increased with the number of does kept together. The probability of kits getting injured was higher in groups of three does than in pens of single-housed does (p = 0.041). When does were pair-housed, kits seemed to have fewer disease symptoms compared to the other treatments. Concerning HCC of kits, there was no significant difference between the housing systems (p > 0.05). The mean HCC of kits was 2.94 pg/mg, while pair housing had the lowest HCC (2.59 pg/mg). This study focused on the welfare of kits from group-housed does. From this perspective, pair housing of does may be appropriate to allow social interaction between does without unduly affecting the welfare of their kits. Full article